Vegetable fields are often contaminated by heavy metals,and Spodoptera exigua is a major vegetable pest which is stressed by heavy metals mainly by feeding.In this study,cadmium accumulation in the tissues of S.exigua...Vegetable fields are often contaminated by heavy metals,and Spodoptera exigua is a major vegetable pest which is stressed by heavy metals mainly by feeding.In this study,cadmium accumulation in the tissues of S.exigua exposed to cadmium and its effects on the growth and development of the parents and the offspring were investigated.Under the stress of different concentrations of cadmium(0.2,3.2,and 51.2 mg kg^(-1)),the cadmium content in each tissue of S.exigua increased in a dose-dependent manner.At the larval stage,the highest cadmium accumulation was found in midgut in all three cadmium treatments,but at the adult stage,the highest cadmium content was found in fat body.In addition,the cadmium content in ovaries was much higher than in testes.When F1S.exigua was stressed by cadmium and the F_(2)generation was not fed a cadmium-containing diet,the larval survival,pupation rate,emergence rate and fecundity of the F_(2)generation were significantly reduced in the 51.2 mg kg^(-1)treatment compared to the corresponding F1generation.Even in the F_(2)generation of the 3.2 mg kg^(-1)treatment,the fecundity was significantly lower than in the parental generation.The fecundity of the only-female stressed treatment was significantly lower than that of the only-male stressed treatment at the 3.2 and 51.2 mg kg^(-1)cadmium exposure levels.When only mothers were stressed at the larval stage,the fecundity of the F_(2)generation was significantly lower than that of the F1generation in the 51.2 mg kg^(-1)treatment,and it was also significantly lower than in the 3.2 and 0.2 mg kg^(-1)treatments.The results of our study can provide useful information for forecasting the population increase trends under different heavy metal stress conditions and for the reliable environmental risk assessment of heavy metal pollution.展开更多
Cytochrome P450s(CYPs)are the largest family of enzymes in plant and play multifarious roles in development and defense but the available information about the CYP superfamily in citrus is very limited.Here we provide...Cytochrome P450s(CYPs)are the largest family of enzymes in plant and play multifarious roles in development and defense but the available information about the CYP superfamily in citrus is very limited.Here we provide a comprehensive genome-wide analysis of the CYP superfamily in Citrus clementina genome,identifying 301 CYP genes grouped into ten clans and 49 families.The characteristics of both gene structures and motif compositions strongly supported the reliability of the phylogenetic relationship.Duplication analysis indicated that tandem duplication was the major driving force of expansion for this superfamily.Promoter analysis revealed numerous cis-acting elements related to various responsiveness.RNA-seq data elucidated their expression patterns in citrus fruit peel both during development and in response to UV-B.Furthermore,we characterize a UV-B-induced CYP gene(Ciclev10019637m,designated CitF3′H)as a f lavonoid 3-hydroxylase for the first time.CitF3 H catalyzed numerous f lavonoids and favored naringenin in yeast assays.Virusinduced silencing of CitF3′ H in citrus seedlings significantly reduced the levels of 3′-hydroxylated f lavonoids and their derivatives.These results together with the endoplasmic reticulum-localization of CitF3 H in plant suggest that this enzyme is responsible for the biosynthesis of 3-hydroxylated f lavonoids in citrus.Taken together,our findings provide extensive information about the CYP superfamily in citrus and contribute to further functional verification.展开更多
Huanglongbing(HLB) is a devastating disease that has led to an acute crisis for growers of citrus, one of the world's most important fruit crops. The phloem-feeding Asian citrus psyllid(ACP), Diaphorina citri, is ...Huanglongbing(HLB) is a devastating disease that has led to an acute crisis for growers of citrus, one of the world's most important fruit crops. The phloem-feeding Asian citrus psyllid(ACP), Diaphorina citri, is the main pest at the new shoot stage and is the only natural vector of HLB pathogenic bacteria. Little is known about how plants perceive and defend themselves from this destructive pest. Here, we characterized changes in the expression of various genes in citrus plants that were continuously infested by D. citri for different durations(12, 24, and 48 h). A total of 5 219 differentially expressed genes(DEGs) and 643 common DEGs were identified across all time points. Several pathways related to defense were activated, such as peroxisome, alpha-linolenic acid metabolism, and phenylpropanoid and terpenoid biosynthesis, and some pathways related to growth and signal transduction were suppressed in response to D. citri infestation. The expression of genes including kinases(CML44, CIPK6, and XTH6), phytohormones(SAMT, LOX6, and NPR3), transcription factors(bHLH162, WRKY70, and WRKY40), and secondary metabolite synthesis-related genes(PAL, 4CL2, UGT74B1 and CYP82G1) was significantly altered in response to D. citri infestation. The findings of this study greatly enhance our understanding of the mechanisms underlying the defense response of citrus plants to D. citri infestation at the molecular level. Functional characterization of the candidate defense-related genes identified in this study will aid the molecular breeding of insect-resistant citrus varieties.展开更多
Seedless citrus has become one of the breeding goals due to its high edible ratio and convenience in fresh consumption and processing.In this study, the ‘Hongjiangcheng' sweet orange(WT) and its seedless mutant(M...Seedless citrus has become one of the breeding goals due to its high edible ratio and convenience in fresh consumption and processing.In this study, the ‘Hongjiangcheng' sweet orange(WT) and its seedless mutant(MT) after cobalt-60 radiation were selected to study the formation metabolism of citrus seedless phenotype. Compared with WT, the MT had altered primary metabolite contents, as indicated by GC-MS analysis. The mature pollen of the MT was mostly distorted and shrunken, and the orange mutant exhibited significantly lower fertility than the WT. Through pollination experiments and paraffin sectioning of the MT, we observed self-compatibility during pollen tube germination in situ, in combination with the absence of natural parthenocarpy and arrested zygotic embryo development at the fourth week after pollination. From transcriptomic analyses of ovules in the fourth week, 815 differentially expressed genes(DEGs) were identified.Furthermore, according to the annotation of gene function and qRT-PCR analysis, Cs4g10930, Cs5g21900 and orange1.1t02243 were identified as candidate genes that may govern the mechanism of seedlessness. Finally, Agrobacterium-mediated transformation verified that the overexpression of Cs4g10930 and Cs5g21900 in Newhall navel orange calli inhibited embryoid production. This study provides a better understanding of seedless formation in citrus and two key genes that may play an important role in the early selection of seedless lines in citrus breeding programs.展开更多
Low-affinity nitrate transporter genes have been identified in subfamilies 4-8 of the rice nitrate transporter 1(NRT1)/peptide transporter family(NPF),but the OsNPF3 subfamily responsible for nitrate and phytohormone ...Low-affinity nitrate transporter genes have been identified in subfamilies 4-8 of the rice nitrate transporter 1(NRT1)/peptide transporter family(NPF),but the OsNPF3 subfamily responsible for nitrate and phytohormone transport and rice growth and development remains unknown.In this study,we described OsNPF3.1 as an essential nitrate and phytohormone transporter gene for rice tillering and nitrogen utilization efficiency(NUtE).OsNPF3.1 possesses four major haplotypes of its promoter sequence in 517 cultivars,and its expression is positively associated with tiller number.Its expression was higher in the basal part,culm,and leaf blade than in other parts of the plant,and was strongly induced by nitrate,abscisic acid(ABA)and gibberellin 3(GA_3)in the root and shoot of rice.Electrophysiological experiments demonstrated that OsNPF3.1 is a pH-dependent low-affinity nitrate transporter,with rice protoplast uptake assays showing it to be an ABA and GA_3 transporter.OsNPF3.1 overexpression significantly promoted ABA accumulation in the roots and GA accumulation in the basal part of the plant which inhibited axillary bud outgrowth and rice tillering,especially at high nitrate concentrations.The NUtE of OsNPF3.1-overexpressing plants was enhanced under low and medium nitrate concentrations,whereas the NUtE of OsNPF3.1 clustered regularly interspaced short palindromic repeats(CRISPR)plants was increased under high nitrate concentrations.The results indicate that OsNPF3.1 transports nitrate and phytohormones in different rice tissues under different nitrate concentrations.The altered OsNPF3.1 expression improves NUtE in the OsNPF3.1-overexpressing and CRISPR lines at low and high nitrate concentrations,respectively.展开更多
The Citrus tristeza virus(CTV) uses 3 silencing suppressor genes, p20, p23 and p25, to resist the attacks from its Citrus hosts. Inactivating these genes is therefore obviously a potential defensive option in addition...The Citrus tristeza virus(CTV) uses 3 silencing suppressor genes, p20, p23 and p25, to resist the attacks from its Citrus hosts. Inactivating these genes is therefore obviously a potential defensive option in addition to the current control strategies including aphid management and the use of mild strain cross protection. In this study, we cloned partial DNA fragments from the three genes, and used them to construct vectors for expressing hairpin RNAs(hp RNAs). To facilitate the formation of hp RNAs, the constructs were introduced in a loop structure. Following transformation of sour orange(Citrus aurantium) with these constructs, 8 p20 hp RNA(hp20) and 1 p25 hp RNA(hp25) expressing lines were obtained. The 7 hp20 transgenic lines were further characterized. Their reactions to CTV were tested following inoculation with CT14 A and/or TR-L514, both of which are severe strains. Results showed that 3 lines(hp20-5, hp20-6 and hp20-8) were completely resistant to TR-L514 under greenhouse conditions for no detectable viral load was found in their leaves by PCR. However, they exhibited only partial suppression of TR-L514 under screen house conditions since the virus was detected in their leaves, though 2 months later compared to non-transgenic controls. Further tests showed that hp20-5 was tolerant also to CT14 A under screen house conditions. The growth of hp20-5 was much better than others including the controls that were concurrently challenged with CT14 A. These results showed that expressing p20 hp RNA was sufficient to c onfer sour orange with CTV resistance/tolerance.展开更多
The genetic regulatory mechanisms that govern natural corolla senescence in petunia are not well understood.To identify key genes and pathways that regulate the process,we performed a transcriptome analysis in petunia...The genetic regulatory mechanisms that govern natural corolla senescence in petunia are not well understood.To identify key genes and pathways that regulate the process,we performed a transcriptome analysis in petunia corolla at four developmental stages,including corolla fully opening without anther dehiscence(D0),corolla expansion,2 days after anthesis(D2),corolla with initial signs of senescence(D4),and wilting corolla(D7).We identified large numbers of differentially expressed genes(DEGs),ranging from 4626 between the transition from D0 and D2,1116 between D2 and D4,a transition to the onset of flower senescence,and 327 between D4 and D7,a developmental stage representing flower senescence.KEGG analysis showed that the auxin-and ethylene-related hormone biosynthesis and signaling transduction pathways were significantly activated during the flower development and highly upregulated at onset of flower senescence.Ethylene emission was detected at the D2 to D4 transition,followed by a large eruption at the D4 to D7 transition.Furthermore,large numbers of transcription factors(TFs)were activated over the course of senescence.Functional analysis by virus-induced gene silencing(VIGS)experiments demonstrated that inhibition of the expression of TFs,such as ethylene-related ERF,auxin-related ARF,bHLH,HB,and MADS-box,significantly extended or shortened flower longevity.Our data suggest that hormonal interaction between auxin and ethylene may play critical regulatory roles in the onset of natural corolla senescence in petunia.展开更多
The acetylcholinesterase 2(AChE2)cloned from Plutella xylostella was first successfully expressed in methylotrophic yeast Pichia pastoris GS115.One transformant with high-level expression of the recombinant AChE(rAChE...The acetylcholinesterase 2(AChE2)cloned from Plutella xylostella was first successfully expressed in methylotrophic yeast Pichia pastoris GS115.One transformant with high-level expression of the recombinant AChE(rAChE,23.2 U mL^(-1)in supernatant)was selected by plating on increasing concentrations of antibiotic G418 and by using a simple and specific chromogenic reaction with indoxyl acetate as a substrate.The maximum production of r ACh E reached about 11.8 mg of the enzyme protein per liter of culture.The r ACh E was first precipitated with ammonium sulfate(50%saturation)and then purified with procainamide affinity column chromatography.The enzyme was purified 12.1-fold with a yield of 22.8%and a high specific activity of 448.3 U mg^(-1).It was sensitive to inhibition by methamidophos and pirimicarb,the calculated 50% inhibitory concentration(IC_(50))values of the two pesticides were 0.357 and 0.888 mg L^(-1),respectively,and the calculated 70% inhibitory concentration(IC_(70))values were 0.521 and 0.839 mg L^(-1),respectively.The results suggested that it has a potential application in the detection of pesticide residues.展开更多
Pitaya(Hylocereus)is the most economically important fleshy-fruited tree of the Cactaceae family that is grown worldwide,and it has attracted significant attention because of its betalain-abundant fruits.Nonetheless,t...Pitaya(Hylocereus)is the most economically important fleshy-fruited tree of the Cactaceae family that is grown worldwide,and it has attracted significant attention because of its betalain-abundant fruits.Nonetheless,the lack of a pitaya reference genome significantly hinders studies focused on its evolution,as well as the potential for genetic improvement of this crop.Herein,we employed various sequencing approaches,namely,PacBio-SMRT,Illumina HiSeq paired-end,10×Genomics,and Hi-C(high-throughput chromosome conformation capture)to provide a chromosome-level genomic assembly of‘GHB’pitaya(H.undatus,2n=2x=22 chromosomes).The size of the assembled pitaya genome was 1.41 Gb,with a scaffold N50 of~127.15 Mb.In total,27,753 protein-coding genes and 896.31Mb of repetitive sequences in the H.undatus genome were annotated.Pitaya has undergone a WGT(whole-genome triplication),and a recent WGD(whole-genome duplication)occurred after the gamma event,which is common to the other species in Cactaceae.A total of 29,328 intact LTR-RTs(~696.45Mb)were obtained in H.undatus,of which two significantly expanded lineages,Ty1/copia and Ty3/gypsy,were the main drivers of the expanded genome.A high-density genetic map of F1 hybrid populations of‘GHB’בDahong’pitayas(H.monacanthus)and their parents were constructed,and a total of 20,872 bin markers were identified(56,380 SNPs)for 11 linkage groups.More importantly,through transcriptomic and WGCNA(weighted gene coexpression network analysis),a global view of the gene regulatory network,including structural genes and the transcription factors involved in pitaya fruit betalain biosynthesis,was presented.Our data present a valuable resource for facilitating molecular breeding programs of pitaya and shed novel light on its genomic evolution,as well as the modulation of betalain biosynthesis in edible fruits.展开更多
An investigation on the soil microbe populations from an agricultural inning area at the Pearl River estuary in Guangdong province, China was conducted via high through-put sequencing. The results revealed abundant di...An investigation on the soil microbe populations from an agricultural inning area at the Pearl River estuary in Guangdong province, China was conducted via high through-put sequencing. The results revealed abundant diversity in the soil bacterial and fungal populations. In total, 197103 sequence tags were obtained from soil samples, most of which represented bacterial genera Actinomycetes, Bacillus and Marinobacter, while a majority of 118378 tags obtained were derived from fungal genera Clostridium, Devosia, Bradyrhizobium, Bdellovibrio, Phenylobacterium, Penicillium, and Emericella. Furthermore, nine physiological indexes (pH, available phosphorous, basic-group nitrogen, available potassium, catalase, sucrose, urease, phosphatase, and organic matters) were measured in three soil samples, and the association between these physiological indexes and microbe population composition was examined. The results revealed obvious inter-sample differences associated with ten dominating microbial groups: genera Clostridium, Devosia, Bradyrhizobium, Bdellovibrio, Phenylobacterium, and Penicillium were mainly impacted by pH (with a positive correlation), genera Sphingomonas and Acinetobacter mainly by available phosphorous (positive correlation), and genera Gemmatimonas and Pseudomonas by both pH and available phosphorous (negative correlation). Our study suggested that regulation of microbial species/populations might help improve soil environment to facilitate the growth of crops’ above-ground parts, and this provides practical information for inning agriculture.展开更多
In order to better distinguish true hybrids in litchi crossbreeding,F1generations of two litchi hybridized combinations namely that‘Xuehuaizi’בGuiwei’and‘Xuehuaizi’בJiaohesanyuehong’were used as ma...In order to better distinguish true hybrids in litchi crossbreeding,F1generations of two litchi hybridized combinations namely that‘Xuehuaizi’בGuiwei’and‘Xuehuaizi’בJiaohesanyuehong’were used as materials to identify true hybrids,to construct mapping populations and to study the genetic diversities of the two populations with EST-SSR markers.The results showed that F1generations of the two hybrid populations could be identified with an identification rate of100%by the combination of four pair primers,respectively,and the 159 individual plants of the two populations were true hybrids.In addition,variations were exited in leaf morphology of the progenies of the two populations and bands of parents absented were occurred on genotype.The clustering analysis showed that 113 F1plants from the hybridized combination of‘Xuehuaizi’בGuiwei’were clustered into six categories(similarity coefficient was 0.68),and 63.72%(72 plants)of which clustered into one group with male parent.The genetic distances between 32 plants(28.3%)and their parents were far which indicated that larger variation or recombinant appeared in these plants.Forty six hybrid progenies of the combination of‘Xuehuaizi’בJiaohesanyuehong’were divided into two categories when the similarity coefficient was 0.642 and most individual plants(60.87%)showed closer genetic relationship with female parent and partial maternal genetic tendency.It is concluded that EST-SSR markers are suitable to identify true hybrids of litchi.The construction of the two F1mapping populations has established basis for further genetic linkage mapping,meanwhile,has accumulated materials for cultivar improvement of litchi.展开更多
The experiment was mainly used to study the effect of insect-proof net mulching cultivation technology on the temperature and humidity of the greenhouse and the spring shoot growth of citrus Shatangju. The results sho...The experiment was mainly used to study the effect of insect-proof net mulching cultivation technology on the temperature and humidity of the greenhouse and the spring shoot growth of citrus Shatangju. The results showed that the 40-mesh translucent insect-proof net had a positive effect on the spring shoot growth of Shatangju in the spring from January to April. In the meantime,according to the change of the temperature and humidity inside and outside the insect-proof net and the change of quantity of Aleyrodidae,Tetranychidae and Phyllocnisidae,it was found that the role of insect-proof net in enhancing the spring shoot growth of Shatangju was possibly achieved by the regulation of citrus pests and the temperature and humidity inside the net.展开更多
Banana(Musa spp.)is an ancient and popular fruit plant with highly nutritious fruit.The pseudo-stem of banana represents on average 75%of the total dry mass but its valorization as a nutritional and industrial by-prod...Banana(Musa spp.)is an ancient and popular fruit plant with highly nutritious fruit.The pseudo-stem of banana represents on average 75%of the total dry mass but its valorization as a nutritional and industrial by-product is limited.Recent advances in metabolomics have paved the way to understand and evaluate the presence of diverse sets of metabolites in different plant parts.This study aimed at exploring the diversity of primary and secondary metabolites in the banana pseudo-stem.Hereby,we identified and quantified 373 metabolites from a diverse range of classes including,alkaloids,flavonoids,lipids,phenolic acids,amino acids and its derivatives,nucleotide and its derivatives,organic acids,lignans and coumarins,tannins,and terpene using the widely-targeted metabolomics approach.Banana pseudo-stem is enriched in metabolites for utilization in the food industry(L-lysine and L-tryptophan,L-glutamic acid,Phenylalanine,Palmitoleic acid,α-Linolenic acid,and Lauric acid,and Adenine)and pharmaceutical industry(Guanosine and Cimidahurinine,Bergapten,Coumarins,Procyanidin A2,Procyanidin B1,Procyanidin B3,Procyanidin B2,and Procyanidin B4,Asiatic acid).The metabolome of banana pseudo-stem with integration across multiomics data may provide the opportunity to exploit the rich metabolome of banana pseudo-stem for industrial and nutritional applications.展开更多
Peptide transport is important for plant tissues where rapid proteolysis occurs,especially during germination and senescence,to enhance redistribution of organic nitrogen(N).However,the biological role of peptide tran...Peptide transport is important for plant tissues where rapid proteolysis occurs,especially during germination and senescence,to enhance redistribution of organic nitrogen(N).However,the biological role of peptide transporters is poorly investigated in rice.We characterized the function of the peptide transporter OsNPF8.1 of rice nitrate transporter 1/peptide transporter family(NPF).Ectopic expression of OsNPF8.1 in yeast revealed that OsNPF8.1 encoded a high-affinity di-/tri-peptide transporter,and the osnpf8.1 mutants had a lower uptake rate of the fluorescent-labelled dipeptide c in leaves of rice seedlings.Histochemical assays showed that OsNPF8.1 was highly expressed in mesophyll cells and vascular parenchyma cells,but not detected in root hairs and epidermises.Expression of OsNPF8.1 was induced by N deficiency,drought,Na Cl and abscisic acid,and kept at a high level in senescing leaves.Under N deficiency conditions,compared with the wild type Zhonghua 11,the osnpf8.1 mutants grew slower at the seedling stage,and had lower grain yield and lower N content in the grains.In contrast,OsNPF8.1-over-expressing rice(OsNPF8.1-OE)grew faster at the seedling stage and had a higher grain yield.The osnpf8.1 seedlings were less tolerant to salt and drought stresses.These results suggested that stress-induced organic N transportation mediated by OsNPF8.1 might contribute to balance plant growth and tolerate to salt/drought stress and N-deficiency.展开更多
Based on the former constructed ‘Tyr1’ locus genetic map in family 9145, from LB6-2 [Clementine mandarin (C. reticulata) × Hamlin orange (C. sinensis)] × Swingle citrumelo (C. paradise × P. trifoliata...Based on the former constructed ‘Tyr1’ locus genetic map in family 9145, from LB6-2 [Clementine mandarin (C. reticulata) × Hamlin orange (C. sinensis)] × Swingle citrumelo (C. paradise × P. trifoliata), 9 markers were chosen for application in evaluating their effectiveness in marker-assisted selection (MAS) for citrus rootstock breeding program from many F1 progeny of Poncirus trifoliata. As the mapping revealed that these markers were estimated within a range of 12.1 cM in the linkage group, and among them, SCO07 co-segregated with ‘Tyr1’, and 7A4R as the closest to ‘Tyr1’ with a distance of 1.5 cM, these markers were basically fitful to go MAS screening. The results of screening P. trifoliata F1 progeny indicated that all the markers were inherited in codominant fashion and most of them were heterozygous on PT (Pomery of P. trifoliata)., marker 4L17R/CfoI and 7A4(1407)/BfaI were proved to be consistently reliable for accurate scoring of genotypes and the revealed polymorphism was basically coincided with the citrus nematode resistant phenotype within tested populations. The polymorphic genotype with marker 4L17R/CfoI was found completely matched up with the phenotype of individuals that conferred high resistance to citrus nematode when the USDA hybrid rootstocks were screened. Utilization of these markers, especially the highly specific 4L17R/CfoI and 7A4(1407)/BfaI, should result in great benefit to world citrus industry for early selection in rootstock-breeding program.展开更多
基金partially supported by the Open Project Program from the Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization(Ministry of Agriculture and Rural Affairs),China(212103)。
文摘Vegetable fields are often contaminated by heavy metals,and Spodoptera exigua is a major vegetable pest which is stressed by heavy metals mainly by feeding.In this study,cadmium accumulation in the tissues of S.exigua exposed to cadmium and its effects on the growth and development of the parents and the offspring were investigated.Under the stress of different concentrations of cadmium(0.2,3.2,and 51.2 mg kg^(-1)),the cadmium content in each tissue of S.exigua increased in a dose-dependent manner.At the larval stage,the highest cadmium accumulation was found in midgut in all three cadmium treatments,but at the adult stage,the highest cadmium content was found in fat body.In addition,the cadmium content in ovaries was much higher than in testes.When F1S.exigua was stressed by cadmium and the F_(2)generation was not fed a cadmium-containing diet,the larval survival,pupation rate,emergence rate and fecundity of the F_(2)generation were significantly reduced in the 51.2 mg kg^(-1)treatment compared to the corresponding F1generation.Even in the F_(2)generation of the 3.2 mg kg^(-1)treatment,the fecundity was significantly lower than in the parental generation.The fecundity of the only-female stressed treatment was significantly lower than that of the only-male stressed treatment at the 3.2 and 51.2 mg kg^(-1)cadmium exposure levels.When only mothers were stressed at the larval stage,the fecundity of the F_(2)generation was significantly lower than that of the F1generation in the 51.2 mg kg^(-1)treatment,and it was also significantly lower than in the 3.2 and 0.2 mg kg^(-1)treatments.The results of our study can provide useful information for forecasting the population increase trends under different heavy metal stress conditions and for the reliable environmental risk assessment of heavy metal pollution.
基金supported by the China Postdoctoral Science Foundation(2021 M692845 and 2021 M700124)the National Natural Science Foundation of China(32101932 and 32072132)the Fundamental Research Funds for the Central Universities(K20220104 and 226-2022-00215).
文摘Cytochrome P450s(CYPs)are the largest family of enzymes in plant and play multifarious roles in development and defense but the available information about the CYP superfamily in citrus is very limited.Here we provide a comprehensive genome-wide analysis of the CYP superfamily in Citrus clementina genome,identifying 301 CYP genes grouped into ten clans and 49 families.The characteristics of both gene structures and motif compositions strongly supported the reliability of the phylogenetic relationship.Duplication analysis indicated that tandem duplication was the major driving force of expansion for this superfamily.Promoter analysis revealed numerous cis-acting elements related to various responsiveness.RNA-seq data elucidated their expression patterns in citrus fruit peel both during development and in response to UV-B.Furthermore,we characterize a UV-B-induced CYP gene(Ciclev10019637m,designated CitF3′H)as a f lavonoid 3-hydroxylase for the first time.CitF3 H catalyzed numerous f lavonoids and favored naringenin in yeast assays.Virusinduced silencing of CitF3′ H in citrus seedlings significantly reduced the levels of 3′-hydroxylated f lavonoids and their derivatives.These results together with the endoplasmic reticulum-localization of CitF3 H in plant suggest that this enzyme is responsible for the biosynthesis of 3-hydroxylated f lavonoids in citrus.Taken together,our findings provide extensive information about the CYP superfamily in citrus and contribute to further functional verification.
基金supported by Key Realm R&D Program of Guangdong Province (Grant No. 2020B0202090005)Special Fund for Scientific Innovation Strategy-construction of High Level Academy of Agriculture Science (Grant No. R2020PY-JG002)the President Foundation of Guangdong Academy of Agricultural Sciences (Grant No. 202030)。
文摘Huanglongbing(HLB) is a devastating disease that has led to an acute crisis for growers of citrus, one of the world's most important fruit crops. The phloem-feeding Asian citrus psyllid(ACP), Diaphorina citri, is the main pest at the new shoot stage and is the only natural vector of HLB pathogenic bacteria. Little is known about how plants perceive and defend themselves from this destructive pest. Here, we characterized changes in the expression of various genes in citrus plants that were continuously infested by D. citri for different durations(12, 24, and 48 h). A total of 5 219 differentially expressed genes(DEGs) and 643 common DEGs were identified across all time points. Several pathways related to defense were activated, such as peroxisome, alpha-linolenic acid metabolism, and phenylpropanoid and terpenoid biosynthesis, and some pathways related to growth and signal transduction were suppressed in response to D. citri infestation. The expression of genes including kinases(CML44, CIPK6, and XTH6), phytohormones(SAMT, LOX6, and NPR3), transcription factors(bHLH162, WRKY70, and WRKY40), and secondary metabolite synthesis-related genes(PAL, 4CL2, UGT74B1 and CYP82G1) was significantly altered in response to D. citri infestation. The findings of this study greatly enhance our understanding of the mechanisms underlying the defense response of citrus plants to D. citri infestation at the molecular level. Functional characterization of the candidate defense-related genes identified in this study will aid the molecular breeding of insect-resistant citrus varieties.
基金supported by the National Key Research and Development Program (Grant No. 2018YFD1000200)Special Fund for Basic Research Funds in Central Universities (Grant No. 2662018PY072)。
文摘Seedless citrus has become one of the breeding goals due to its high edible ratio and convenience in fresh consumption and processing.In this study, the ‘Hongjiangcheng' sweet orange(WT) and its seedless mutant(MT) after cobalt-60 radiation were selected to study the formation metabolism of citrus seedless phenotype. Compared with WT, the MT had altered primary metabolite contents, as indicated by GC-MS analysis. The mature pollen of the MT was mostly distorted and shrunken, and the orange mutant exhibited significantly lower fertility than the WT. Through pollination experiments and paraffin sectioning of the MT, we observed self-compatibility during pollen tube germination in situ, in combination with the absence of natural parthenocarpy and arrested zygotic embryo development at the fourth week after pollination. From transcriptomic analyses of ovules in the fourth week, 815 differentially expressed genes(DEGs) were identified.Furthermore, according to the annotation of gene function and qRT-PCR analysis, Cs4g10930, Cs5g21900 and orange1.1t02243 were identified as candidate genes that may govern the mechanism of seedlessness. Finally, Agrobacterium-mediated transformation verified that the overexpression of Cs4g10930 and Cs5g21900 in Newhall navel orange calli inhibited embryoid production. This study provides a better understanding of seedless formation in citrus and two key genes that may play an important role in the early selection of seedless lines in citrus breeding programs.
基金supported by the the Guizhou Provincial Excellent Young Talents Project of Science and Technology,China(YQK(2023)002)the Guizhou Provincial Science and Technology Projects,China((2022)Key 008)+2 种基金the Guizhou Provincial Science and Technology Support Plan,China((2022)Key 026)the Key Laboratory of Molecular Breeding for Grain and Oil Crops in Guizhou Province,China((2023)008)the Key Laboratory of Functional Agriculture of Guizhou Provincial Higher Education Institutions,China((2023)007)。
文摘Low-affinity nitrate transporter genes have been identified in subfamilies 4-8 of the rice nitrate transporter 1(NRT1)/peptide transporter family(NPF),but the OsNPF3 subfamily responsible for nitrate and phytohormone transport and rice growth and development remains unknown.In this study,we described OsNPF3.1 as an essential nitrate and phytohormone transporter gene for rice tillering and nitrogen utilization efficiency(NUtE).OsNPF3.1 possesses four major haplotypes of its promoter sequence in 517 cultivars,and its expression is positively associated with tiller number.Its expression was higher in the basal part,culm,and leaf blade than in other parts of the plant,and was strongly induced by nitrate,abscisic acid(ABA)and gibberellin 3(GA_3)in the root and shoot of rice.Electrophysiological experiments demonstrated that OsNPF3.1 is a pH-dependent low-affinity nitrate transporter,with rice protoplast uptake assays showing it to be an ABA and GA_3 transporter.OsNPF3.1 overexpression significantly promoted ABA accumulation in the roots and GA accumulation in the basal part of the plant which inhibited axillary bud outgrowth and rice tillering,especially at high nitrate concentrations.The NUtE of OsNPF3.1-overexpressing plants was enhanced under low and medium nitrate concentrations,whereas the NUtE of OsNPF3.1 clustered regularly interspaced short palindromic repeats(CRISPR)plants was increased under high nitrate concentrations.The results indicate that OsNPF3.1 transports nitrate and phytohormones in different rice tissues under different nitrate concentrations.The altered OsNPF3.1 expression improves NUtE in the OsNPF3.1-overexpressing and CRISPR lines at low and high nitrate concentrations,respectively.
基金supported by the International Science & Technology Cooperation Program of China (2012DFA30610)the National Natural Science Foundation of China (30571291)the Special Fund for Agro-Scientific Research in the Public Interest, China (201203075-07)
文摘The Citrus tristeza virus(CTV) uses 3 silencing suppressor genes, p20, p23 and p25, to resist the attacks from its Citrus hosts. Inactivating these genes is therefore obviously a potential defensive option in addition to the current control strategies including aphid management and the use of mild strain cross protection. In this study, we cloned partial DNA fragments from the three genes, and used them to construct vectors for expressing hairpin RNAs(hp RNAs). To facilitate the formation of hp RNAs, the constructs were introduced in a loop structure. Following transformation of sour orange(Citrus aurantium) with these constructs, 8 p20 hp RNA(hp20) and 1 p25 hp RNA(hp25) expressing lines were obtained. The 7 hp20 transgenic lines were further characterized. Their reactions to CTV were tested following inoculation with CT14 A and/or TR-L514, both of which are severe strains. Results showed that 3 lines(hp20-5, hp20-6 and hp20-8) were completely resistant to TR-L514 under greenhouse conditions for no detectable viral load was found in their leaves by PCR. However, they exhibited only partial suppression of TR-L514 under screen house conditions since the virus was detected in their leaves, though 2 months later compared to non-transgenic controls. Further tests showed that hp20-5 was tolerant also to CT14 A under screen house conditions. The growth of hp20-5 was much better than others including the controls that were concurrently challenged with CT14 A. These results showed that expressing p20 hp RNA was sufficient to c onfer sour orange with CTV resistance/tolerance.
基金We thank Chuan-Bei Jiang(Genepioneer Biotechnologies,Nanjing 210014,China)for providing bioinformatics analysisThis work was partially supported by National Natural Science Foundation of China(grant nos.31540052+2 种基金31300469)Jiangsu Natural Science Foundation of China(grant no.BK 20141383)United States Department of Agriculture(USDA)CRIS project 5306-21000-019-00D.
文摘The genetic regulatory mechanisms that govern natural corolla senescence in petunia are not well understood.To identify key genes and pathways that regulate the process,we performed a transcriptome analysis in petunia corolla at four developmental stages,including corolla fully opening without anther dehiscence(D0),corolla expansion,2 days after anthesis(D2),corolla with initial signs of senescence(D4),and wilting corolla(D7).We identified large numbers of differentially expressed genes(DEGs),ranging from 4626 between the transition from D0 and D2,1116 between D2 and D4,a transition to the onset of flower senescence,and 327 between D4 and D7,a developmental stage representing flower senescence.KEGG analysis showed that the auxin-and ethylene-related hormone biosynthesis and signaling transduction pathways were significantly activated during the flower development and highly upregulated at onset of flower senescence.Ethylene emission was detected at the D2 to D4 transition,followed by a large eruption at the D4 to D7 transition.Furthermore,large numbers of transcription factors(TFs)were activated over the course of senescence.Functional analysis by virus-induced gene silencing(VIGS)experiments demonstrated that inhibition of the expression of TFs,such as ethylene-related ERF,auxin-related ARF,bHLH,HB,and MADS-box,significantly extended or shortened flower longevity.Our data suggest that hormonal interaction between auxin and ethylene may play critical regulatory roles in the onset of natural corolla senescence in petunia.
基金supported by a grant from the Public Benefit Research Foundation of China (200903052)the Science and Technology Department of Guangdong Province, China (2009A020101003)
文摘The acetylcholinesterase 2(AChE2)cloned from Plutella xylostella was first successfully expressed in methylotrophic yeast Pichia pastoris GS115.One transformant with high-level expression of the recombinant AChE(rAChE,23.2 U mL^(-1)in supernatant)was selected by plating on increasing concentrations of antibiotic G418 and by using a simple and specific chromogenic reaction with indoxyl acetate as a substrate.The maximum production of r ACh E reached about 11.8 mg of the enzyme protein per liter of culture.The r ACh E was first precipitated with ammonium sulfate(50%saturation)and then purified with procainamide affinity column chromatography.The enzyme was purified 12.1-fold with a yield of 22.8%and a high specific activity of 448.3 U mg^(-1).It was sensitive to inhibition by methamidophos and pirimicarb,the calculated 50% inhibitory concentration(IC_(50))values of the two pesticides were 0.357 and 0.888 mg L^(-1),respectively,and the calculated 70% inhibitory concentration(IC_(70))values were 0.521 and 0.839 mg L^(-1),respectively.The results suggested that it has a potential application in the detection of pesticide residues.
基金This work was supported by the National Natural Science Foundation of China(grant nos.31972367 and 31960578)Key Science and Technology Planning Project of Guangzhou(grant no.201904020015)+2 种基金Science and Technology Program of Zhanjiang(grant no.2019A01003)Science and Technology Program of Guangzhou(grant nos.202002020060,201704020003 and 2014Y2-00164)Key Realm R&D Program of Guangdong Province(grant no.2018B020202011).
文摘Pitaya(Hylocereus)is the most economically important fleshy-fruited tree of the Cactaceae family that is grown worldwide,and it has attracted significant attention because of its betalain-abundant fruits.Nonetheless,the lack of a pitaya reference genome significantly hinders studies focused on its evolution,as well as the potential for genetic improvement of this crop.Herein,we employed various sequencing approaches,namely,PacBio-SMRT,Illumina HiSeq paired-end,10×Genomics,and Hi-C(high-throughput chromosome conformation capture)to provide a chromosome-level genomic assembly of‘GHB’pitaya(H.undatus,2n=2x=22 chromosomes).The size of the assembled pitaya genome was 1.41 Gb,with a scaffold N50 of~127.15 Mb.In total,27,753 protein-coding genes and 896.31Mb of repetitive sequences in the H.undatus genome were annotated.Pitaya has undergone a WGT(whole-genome triplication),and a recent WGD(whole-genome duplication)occurred after the gamma event,which is common to the other species in Cactaceae.A total of 29,328 intact LTR-RTs(~696.45Mb)were obtained in H.undatus,of which two significantly expanded lineages,Ty1/copia and Ty3/gypsy,were the main drivers of the expanded genome.A high-density genetic map of F1 hybrid populations of‘GHB’בDahong’pitayas(H.monacanthus)and their parents were constructed,and a total of 20,872 bin markers were identified(56,380 SNPs)for 11 linkage groups.More importantly,through transcriptomic and WGCNA(weighted gene coexpression network analysis),a global view of the gene regulatory network,including structural genes and the transcription factors involved in pitaya fruit betalain biosynthesis,was presented.Our data present a valuable resource for facilitating molecular breeding programs of pitaya and shed novel light on its genomic evolution,as well as the modulation of betalain biosynthesis in edible fruits.
文摘An investigation on the soil microbe populations from an agricultural inning area at the Pearl River estuary in Guangdong province, China was conducted via high through-put sequencing. The results revealed abundant diversity in the soil bacterial and fungal populations. In total, 197103 sequence tags were obtained from soil samples, most of which represented bacterial genera Actinomycetes, Bacillus and Marinobacter, while a majority of 118378 tags obtained were derived from fungal genera Clostridium, Devosia, Bradyrhizobium, Bdellovibrio, Phenylobacterium, Penicillium, and Emericella. Furthermore, nine physiological indexes (pH, available phosphorous, basic-group nitrogen, available potassium, catalase, sucrose, urease, phosphatase, and organic matters) were measured in three soil samples, and the association between these physiological indexes and microbe population composition was examined. The results revealed obvious inter-sample differences associated with ten dominating microbial groups: genera Clostridium, Devosia, Bradyrhizobium, Bdellovibrio, Phenylobacterium, and Penicillium were mainly impacted by pH (with a positive correlation), genera Sphingomonas and Acinetobacter mainly by available phosphorous (positive correlation), and genera Gemmatimonas and Pseudomonas by both pH and available phosphorous (negative correlation). Our study suggested that regulation of microbial species/populations might help improve soil environment to facilitate the growth of crops’ above-ground parts, and this provides practical information for inning agriculture.
基金Supported by Special Fund of National Natural Science Foundation of China(31272135)Modern Agricultural Industry Technology System of Guangdong Province(LNSG2013-04)
文摘In order to better distinguish true hybrids in litchi crossbreeding,F1generations of two litchi hybridized combinations namely that‘Xuehuaizi’בGuiwei’and‘Xuehuaizi’בJiaohesanyuehong’were used as materials to identify true hybrids,to construct mapping populations and to study the genetic diversities of the two populations with EST-SSR markers.The results showed that F1generations of the two hybrid populations could be identified with an identification rate of100%by the combination of four pair primers,respectively,and the 159 individual plants of the two populations were true hybrids.In addition,variations were exited in leaf morphology of the progenies of the two populations and bands of parents absented were occurred on genotype.The clustering analysis showed that 113 F1plants from the hybridized combination of‘Xuehuaizi’בGuiwei’were clustered into six categories(similarity coefficient was 0.68),and 63.72%(72 plants)of which clustered into one group with male parent.The genetic distances between 32 plants(28.3%)and their parents were far which indicated that larger variation or recombinant appeared in these plants.Forty six hybrid progenies of the combination of‘Xuehuaizi’בJiaohesanyuehong’were divided into two categories when the similarity coefficient was 0.642 and most individual plants(60.87%)showed closer genetic relationship with female parent and partial maternal genetic tendency.It is concluded that EST-SSR markers are suitable to identify true hybrids of litchi.The construction of the two F1mapping populations has established basis for further genetic linkage mapping,meanwhile,has accumulated materials for cultivar improvement of litchi.
基金Supported by Special Construction Project of Modern Agriculture(Citrus)Industry Technology System(cars-27)
文摘The experiment was mainly used to study the effect of insect-proof net mulching cultivation technology on the temperature and humidity of the greenhouse and the spring shoot growth of citrus Shatangju. The results showed that the 40-mesh translucent insect-proof net had a positive effect on the spring shoot growth of Shatangju in the spring from January to April. In the meantime,according to the change of the temperature and humidity inside and outside the insect-proof net and the change of quantity of Aleyrodidae,Tetranychidae and Phyllocnisidae,it was found that the role of insect-proof net in enhancing the spring shoot growth of Shatangju was possibly achieved by the regulation of citrus pests and the temperature and humidity inside the net.
基金This research was financially supported by National Key Research and Development Project(2018YFD1000102,2019YFD1000200,2019YFD1000901)Guangdong Science and Technology Project(2019B030316007)+2 种基金special fund for scientific innovation strategy-construction of high level Academy of Agriculture Science(R2018PY-QY004,R2017PY-QY001,R2017PY-JX002)Guangzhou national modern agricultural industry science and technology innovation center project(2018kczx06)National Banana Industry and Technology System Project(CARS-31-01).
文摘Banana(Musa spp.)is an ancient and popular fruit plant with highly nutritious fruit.The pseudo-stem of banana represents on average 75%of the total dry mass but its valorization as a nutritional and industrial by-product is limited.Recent advances in metabolomics have paved the way to understand and evaluate the presence of diverse sets of metabolites in different plant parts.This study aimed at exploring the diversity of primary and secondary metabolites in the banana pseudo-stem.Hereby,we identified and quantified 373 metabolites from a diverse range of classes including,alkaloids,flavonoids,lipids,phenolic acids,amino acids and its derivatives,nucleotide and its derivatives,organic acids,lignans and coumarins,tannins,and terpene using the widely-targeted metabolomics approach.Banana pseudo-stem is enriched in metabolites for utilization in the food industry(L-lysine and L-tryptophan,L-glutamic acid,Phenylalanine,Palmitoleic acid,α-Linolenic acid,and Lauric acid,and Adenine)and pharmaceutical industry(Guanosine and Cimidahurinine,Bergapten,Coumarins,Procyanidin A2,Procyanidin B1,Procyanidin B3,Procyanidin B2,and Procyanidin B4,Asiatic acid).The metabolome of banana pseudo-stem with integration across multiomics data may provide the opportunity to exploit the rich metabolome of banana pseudo-stem for industrial and nutritional applications.
基金supported by the National Natural Science Foundation of China(Grant No.31772384)Science and Technology Project of Zhanjiang,Guangdong Province,China(Grant No.2021A05030)。
文摘Peptide transport is important for plant tissues where rapid proteolysis occurs,especially during germination and senescence,to enhance redistribution of organic nitrogen(N).However,the biological role of peptide transporters is poorly investigated in rice.We characterized the function of the peptide transporter OsNPF8.1 of rice nitrate transporter 1/peptide transporter family(NPF).Ectopic expression of OsNPF8.1 in yeast revealed that OsNPF8.1 encoded a high-affinity di-/tri-peptide transporter,and the osnpf8.1 mutants had a lower uptake rate of the fluorescent-labelled dipeptide c in leaves of rice seedlings.Histochemical assays showed that OsNPF8.1 was highly expressed in mesophyll cells and vascular parenchyma cells,but not detected in root hairs and epidermises.Expression of OsNPF8.1 was induced by N deficiency,drought,Na Cl and abscisic acid,and kept at a high level in senescing leaves.Under N deficiency conditions,compared with the wild type Zhonghua 11,the osnpf8.1 mutants grew slower at the seedling stage,and had lower grain yield and lower N content in the grains.In contrast,OsNPF8.1-over-expressing rice(OsNPF8.1-OE)grew faster at the seedling stage and had a higher grain yield.The osnpf8.1 seedlings were less tolerant to salt and drought stresses.These results suggested that stress-induced organic N transportation mediated by OsNPF8.1 might contribute to balance plant growth and tolerate to salt/drought stress and N-deficiency.
基金supported in part by grants from the USDA NRICGP (9201765, 9600748)USDA/National Citrus Research Council (98012205)the Florida Citrus Production Research Advisory Council, USA(942-27)
文摘Based on the former constructed ‘Tyr1’ locus genetic map in family 9145, from LB6-2 [Clementine mandarin (C. reticulata) × Hamlin orange (C. sinensis)] × Swingle citrumelo (C. paradise × P. trifoliata), 9 markers were chosen for application in evaluating their effectiveness in marker-assisted selection (MAS) for citrus rootstock breeding program from many F1 progeny of Poncirus trifoliata. As the mapping revealed that these markers were estimated within a range of 12.1 cM in the linkage group, and among them, SCO07 co-segregated with ‘Tyr1’, and 7A4R as the closest to ‘Tyr1’ with a distance of 1.5 cM, these markers were basically fitful to go MAS screening. The results of screening P. trifoliata F1 progeny indicated that all the markers were inherited in codominant fashion and most of them were heterozygous on PT (Pomery of P. trifoliata)., marker 4L17R/CfoI and 7A4(1407)/BfaI were proved to be consistently reliable for accurate scoring of genotypes and the revealed polymorphism was basically coincided with the citrus nematode resistant phenotype within tested populations. The polymorphic genotype with marker 4L17R/CfoI was found completely matched up with the phenotype of individuals that conferred high resistance to citrus nematode when the USDA hybrid rootstocks were screened. Utilization of these markers, especially the highly specific 4L17R/CfoI and 7A4(1407)/BfaI, should result in great benefit to world citrus industry for early selection in rootstock-breeding program.
