Sugar plays an important role in apple fruit development,appearance and quality as well as contributing to a plant’s water stress response.Trehalose and the trehalose biosynthetic metabolic pathways are part of the s...Sugar plays an important role in apple fruit development,appearance and quality as well as contributing to a plant’s water stress response.Trehalose and the trehalose biosynthetic metabolic pathways are part of the sugar signaling system in plants,which are important regulator of water stress response in apple.The effect of water stress treatments applied to apple trees and the corresponding effects of ABA on developmental fruit quality were examined for indicators of fruit quality during fruit development.The results indicated that the severe water stress treatment(W2)occurring after the last stage of fruit cell division caused a decrease in the color and size of fruit.The moderate water stress(W1)occurring after the last stage of fruit cell enlargement(S2)caused an increase in the content of fructose and sorbitol while the apple fruit shape was not affected.These changes in sugar are related to the activity of sugar metabolic enzymes.While the enzymatic activity of vacuolar acid invertase(vAINV)was higher,that of sucrose-phosphate synthase(SPS)was lower in water stress treated fruit throughout the developmental period.This indicates that enhanced sucrose degradation and reduced sucrose synthesis leads to an overall reduced sucrose content during times of drought.Thus,water stress reduced sucrose content.Whereas the content of endogenous trehalose and ABA were the highest in water stress treated fruit.A moderate water stress(W1)imposed on apple trees via water restriction(60%–65%of field capacity)after the fruit cell enlargement phase of fruit development yielded sweeter fruit of higher economic value.展开更多
Sugar metabolism plays an essential role in plant male reproduction. Defects in sugar metabolism during anther and pollen development often result in genic male sterility(GMS). In this review, we summarize the recent ...Sugar metabolism plays an essential role in plant male reproduction. Defects in sugar metabolism during anther and pollen development often result in genic male sterility(GMS). In this review, we summarize the recent progresses of the sugar metabolism-related GMS genes and their roles during plant anther and pollen development, including callose wall and primexine formation, intine development, pollen maturation and starch accumulation, anther dehiscence, and pollen germination and tube growth. We predict 112 putative sugar metabolic GMS genes in maize based on bioinformatics and RNA-seq analyses, and most of them have peak expression patterns during middle or late anther developmental stages.Finally, we outline the potential applications of sugar metabolic GMS genes in crop hybrid breeding and seed production. This review will deepen our understanding on sugar metabolic pathways in controlling pollen development and male fertility in plants.展开更多
Sugar composition not only affects fruit flavor but is also an important determinant of fruit taste and consumer preference.In this study,changes in the sugar content and sugar-metabolizing enzymes were investigated f...Sugar composition not only affects fruit flavor but is also an important determinant of fruit taste and consumer preference.In this study,changes in the sugar content and sugar-metabolizing enzymes were investigated from different sections of various fruit development phases of‘Hongshuijing’pitaya(Hylocereus monacanthus).Genes related to sugar metabolism were also screened by transcriptome analyses.The results indicated that glucose was the major sugar in mature pitaya fruit,and was mainly regulated by vacuolar acid invertase(VAI)and sucrose synthase(SS)(degradative direction).Sugar accumulation varied in pulp between different sections of the pitaya fruit.VAI,neutral invertase(NI)and SS(degradative direction)are crucial enzymes for sugar accumulation in pitaya.The expression of 17 genes related to sucrose metabolism obtained from seven databases[NCBI non-redundant protein database(Nr),NCBI non-redundant nucleotide sequence database(Nt),EuKaryotic Orthologous Groups(KOG),The Protein Families(Pfam),Kyoto Encyclopedia of Genes and Genomes(KEGG),Swiss-prot,and Gene Ontology(GO)]were analyzed in different pitaya pulp sections.HpVAI1 had the highest relative expression level on the 29th day after pollination(DAP).Positive correlations were found between HpVAI1 expression and VAI activity;HpNI4 and NI activity;HpSS2,HpSS5,and SS activity(synthetic direction),indicating that HpVAI1,HpNI4,and HpSS2 and HpSS5 were involved in the regulation of VAI,NI,and SS(synthetic direction),respectively.HpVAI1 and HpNI4 regulated sucrose degradation and the accumulation of glucose and fructose,while HpSS2 and HpSS5 regulated sucrose synthesis.These results suggest that HpVAI1 plays a key role in sugar metabolism during fruit development of‘Hongshuijing’pitaya.The results of this study provide new information about sugar metabolism in pitaya fruit that could help improve fruit quality and the breeding of new cultivars.展开更多
The steviol glycosides(SGs)in stevia(Stevia rebaudiana Bertoni)leaves are becoming increasingly valuable due to its high sweetness but low calorific value,which is driving the development of stevia commercial cultivat...The steviol glycosides(SGs)in stevia(Stevia rebaudiana Bertoni)leaves are becoming increasingly valuable due to its high sweetness but low calorific value,which is driving the development of stevia commercial cultivation.Optimizing fertilization management can effectively increase SGs productivity,but knowledge on the relationship between potassium(K)fertilization and SGs production is still lacking.In this study,pot experiments were conducted in order to investigate the effect of K deficiency on SGs synthesis in stevia leaves,as well as the underlying mechanisms.Our results showed that when compared with standard K fertilization,K deficiency treatment has no significant effect on the biomass of stevia plant grown in a given soil with high K contents.However,K deficiency critically decreased leaf SGs contents as well as the expression of SGs synthesis-related genes.The contents of different sugar components decreased and the activities of sugar metabolism-related enzymes were inhibited under the K deficiency condition.Moreover,spraying sucrose on the leaves of stevia seedlings diminished the inhibitory effect caused by K deficiency.Our results also revealed the significant positive correlations between sucrose,glucose and SGs contents.Overall,our results suggest that K deficiency would suppress the synthesis of SGs in stevia leaves,and this effect may be mediated by the leaf sugar metabolism.Our findings provide new insights into the improvement of SGs production potential.展开更多
The effect of NaCl with or without silicon on the growth and metabolism in rice seedlings cv. MTU1010 was studied. In these seedlings, the oxidative stress has been observed with NaCl treatments and the levels of prol...The effect of NaCl with or without silicon on the growth and metabolism in rice seedlings cv. MTU1010 was studied. In these seedlings, the oxidative stress has been observed with NaCl treatments and the levels of proline, H<sub>2</sub>O<sub>2</sub> and malondialdehyde contents were increased whereas catalase activity was decreased. NaCl exposure at 25 mM, 50 mM and 100 mM concentrations in the test seedlings resulted in an increase in both reducing and non-reducing sugar content. There was a decrease in starch contents and the activity of starch phosphorylase was increased. NaCl stress also affected the activities of different carbohydrate metabolizing enzymes. The activities of sucrose synthase and sucrose phosphate synthase were increased, while the activity of acid invertase was decreased. Joint application of silicon with NaCl showed significant alterations on all parameters tested under the purview of NaCl treatment alone leading to better growth and metabolism in rice seedlings. Thus the use of silicon enriched fertilizers may help to grow healthy rice plants in NaCl rich soil.展开更多
In this study,high performance liquid chromatography(HPLC)and RNA-seq transcriptome sequencing were used to study the changes in soluble sugar components and flavonoids in Prunus persica‘Jinxiangyu’at different deve...In this study,high performance liquid chromatography(HPLC)and RNA-seq transcriptome sequencing were used to study the changes in soluble sugar components and flavonoids in Prunus persica‘Jinxiangyu’at different developmental stages(20–90 d after flowering)and screen the key genes regulating the formation of soluble sugar and flavonoids in the fruits.The results showed that 60–85 d after flowering was the key stage of quality formation of Prunus persica‘Jinxiangyu’,and the content of soluble sugar,soluble solid,fructose,and sucrose in the fruit increased significantly during this period.The sugar content of ripe fruits was mainly fructose and sucrose.The content of kaempferol glycoside was low in the fruit.Quercetin glycoside content was higher in the young fruit stage and decreased with fruit maturity.There were no anthocyanin compounds in the fruit.The expression levels of genes involved in flavonoid metabolism(ANS,DFR,F3H,FLS,4CL1,etc.)were low in the fruit.A total of 181 differentially expressed genes were identified during fruit development to participate in five sugar metabolism pathways,among which the SDH gene had a higher expression level,which continuously rised in the later stage of fruit development.It mainly promoted the accumulation of fructose content in the later stage of fruit development.The expression levels of SPS1,SS,and SS1 genes were continuously up-regulated,which played a key role in sucrose regulation.The higher expression levels of SUS3 and INVA genes in the early stage of fruit development promoted the degradation of sucrose.展开更多
Sugars are fundamental metabolites synthesized in leaves and further delivered to fruit in fruit crops.They not only provide"sweetness"as fruit quality traits,but also function as signaling molecules to modu...Sugars are fundamental metabolites synthesized in leaves and further delivered to fruit in fruit crops.They not only provide"sweetness"as fruit quality traits,but also function as signaling molecules to modulate the responses of fruit to environmental stimuli.Therefore,the understanding to the molec-ular basis for sugar metabolism and transport is crucial for improving fruit quality and dissecting responses to abiotic/biotic factors.Here,we provide a review for mol ecular components involved in sugar metabolism and transport,crostalk with hormone signaling and the roles of sugars in responses to abiotic and biotic stresses.Moreover,we also envisage the strategies for optimizing sugar metabolism during fruit quality maintenance.展开更多
Invertase （INV） hydrolyzes sucrose into glucose and fructose, thereby playing key roles in primary metabolism and plant development. Based on their pH optima and sub-cellular locations, INVs are categorized into cel...Invertase （INV） hydrolyzes sucrose into glucose and fructose, thereby playing key roles in primary metabolism and plant development. Based on their pH optima and sub-cellular locations, INVs are categorized into cell wall, cytoplasmic, and vacuolar subgroups, abbreviated as CWlN, CIN, and VlN, respectively. The broad importance and implications of INVs in plant development and crop productivity have attracted enormous interest to examine INV function and regulation from multiple perspectives. Here, we review some exciting advances in this area over the last two decades, focusing on （1） new or emerging roles of INV in plant development and regulation at the post-translational level through interaction with inhibitors, （2） cross-talk between INV-mediated sugar signaling and hormonal control of development, and （3） sugar- and INV-mediated responses to drought and heat stresses and their impact on seed and fruit set. Finally, we discuss major questions arising from this new progress and outline future directions for unraveling mechanisms underlying INV-mediated plant development and their potential applications in plant biotechnology and agriculture.展开更多
Vitamin B(VB1),including thiamin,thiamin monophosphate(TMP),and thiamin pyrophosphate(TPP),is an essential micronutrient for all living organisms.Nevertheless,the precise function of VB1 in rice remains unclear.Here,w...Vitamin B(VB1),including thiamin,thiamin monophosphate(TMP),and thiamin pyrophosphate(TPP),is an essential micronutrient for all living organisms.Nevertheless,the precise function of VB1 in rice remains unclear.Here,we described a VB1 auxotrophic mutant,chlorotic lethal seedling(cles)from the mutation of OsTH1,which displayed collapsed chloroplast membrane system and decreased pigment content.OsTH1 encoded a phosphomethylpyrimidine kinase/thiamin-phosphate pyrophosphorylase,and was expressed in various tissues,especially in seedlings,leaves,and young panicles.The VB1 content in cles was markedly reduced,despite an increase in the expression of VB1 synthesis genes.The decreased TPP content affected the tricarboxylic acid cycle,pentose phosphate pathway,and de novo fatty acid synthesis,leading to a reduction in fatty acids(C16:0 and C18:0)and sugars(sucrose and glucose)of cles.Additionally,irregular expression of chloroplast membrane synthesis genes led to membrane collapse.We also found that alternative splicing and translation allowed OsTH1 to be localized to both chloroplast and cytosol.Our study revealed that OsTH1 was an essential enzyme in VB1 biosynthesis and played crucial roles in seedling growth and development by participating in fatty acid and sugar metabolism,providing new perspectives on VB1 function in rice.展开更多
Kiwifruit is a recently domesticated horticultural fruit crop with substantial economic and nutritional value,especially because of the high content of vitamin C in its fruit.In this study,we de novo assembled two tel...Kiwifruit is a recently domesticated horticultural fruit crop with substantial economic and nutritional value,especially because of the high content of vitamin C in its fruit.In this study,we de novo assembled two telomere-to-telomere kiwifruit genomes from Actinidia chinensis var.‘Donghong’(DH)and Actinidia latifolia‘Kuoye’(KY),with total lengths of 608327852 and 640561626 bp for 29 chromosomes,respectively.With a burst of structural variants involving inversion,translocations,and duplications within 8.39 million years,the metabolite content of DH and KY exhibited differences in saccharides,lignans,and vitamins.A regulatory ERF098 transcription factor family has expanded in KY and Actinidia eriantha,both of which have ultra-high vitamin C content.With each assembly phased into two complete haplotypes,we identified allelic variations between two sets of haplotypes,leading to protein sequence variations in 26494 and 27773 gene loci and allele-specific expression of 4687 and 12238 homozygous gene pairs.Synchronized metabolome and transcriptome changes during DH fruit development revealed the same dynamic patterns in expression levels and metabolite contents;free fatty acids and flavonols accumulated in the early stages,but sugar substances and amino acids accumulated in the late stages.The AcSWEET9b gene that exhibits allelic dominance was further identified to positively correlate with high sucrose content in fruit.Compared with wild varieties and other Actinidia species,AcSWEET9b promoters were selected in red-flesh kiwifruits that have increased fruit sucrose content,providing a possible explanation on why red-flesh kiwifruits are sweeter.Collectively,these two gap-free kiwifruit genomes provide a valuable genetic resource for investigating domestication mechanisms and genome-based breeding of kiwifruit.展开更多
Bumblebees play an important role in maintaining the balance of natural and agricultural ecosystems,and the characteristic gut microbiota of bumblebees exhibit significant mutualistic functions.China has the highest d...Bumblebees play an important role in maintaining the balance of natural and agricultural ecosystems,and the characteristic gut microbiota of bumblebees exhibit significant mutualistic functions.China has the highest diversity of bumblebees;however,gut microbiota of Chinese bumblebees have mostly been investigated through cultureindependent studies.Here,we analyzed the gut communities of bumblebees from Sichuan,Yunnan,and Shaanxi provinces in China through 16S ribosomal RNA amplicon sequencing and bacterial isolation.It revealed that the bumblebees examined in this study harbored two gut enterotypes as previously reported:one is dominated by Gilliamella and Snodgrassella,and the other is distinguished by prevalent environmental species.The gut compositions obviously varied among different individual bees.We then isolated 325 bacterial strains and the comparative genomic analysis of Gillianiella strains revealed that galactose and pectin digestion pathways were conserved in strains from bumblebees,while genes for the utilization of arabinose,mannose,xylose,and rhamnose were mostly lost.Only two strains from the Chinese bumblebees possess the multidrug-resistant gene emrB,which is phylogenetically closely related to that from the symbionts of soil entomopathogenic nematode.In contrast,tetracycline-resistant genes were uniquely present in three strains from the USA.Our results illustrate the prevalence of strain-level variations in the metabolic potentials and the distributions of antibiotic-resistant genes in Chinese bumblebee gut bacteria.展开更多
基金supported by the National Key Technology R&D Program(Grant No.2014BAD16B06)the project of the China Agriculture Research System(Grant No.CARS-28)。
文摘Sugar plays an important role in apple fruit development,appearance and quality as well as contributing to a plant’s water stress response.Trehalose and the trehalose biosynthetic metabolic pathways are part of the sugar signaling system in plants,which are important regulator of water stress response in apple.The effect of water stress treatments applied to apple trees and the corresponding effects of ABA on developmental fruit quality were examined for indicators of fruit quality during fruit development.The results indicated that the severe water stress treatment(W2)occurring after the last stage of fruit cell division caused a decrease in the color and size of fruit.The moderate water stress(W1)occurring after the last stage of fruit cell enlargement(S2)caused an increase in the content of fructose and sorbitol while the apple fruit shape was not affected.These changes in sugar are related to the activity of sugar metabolic enzymes.While the enzymatic activity of vacuolar acid invertase(vAINV)was higher,that of sucrose-phosphate synthase(SPS)was lower in water stress treated fruit throughout the developmental period.This indicates that enhanced sucrose degradation and reduced sucrose synthesis leads to an overall reduced sucrose content during times of drought.Thus,water stress reduced sucrose content.Whereas the content of endogenous trehalose and ABA were the highest in water stress treated fruit.A moderate water stress(W1)imposed on apple trees via water restriction(60%–65%of field capacity)after the fruit cell enlargement phase of fruit development yielded sweeter fruit of higher economic value.
基金supported by the National Key Research and Development Program of China(2018YFD0100806,2017YFD0101201 and 2017YFD0102001)the National Natural Science Foundation of China(31871702,31971958 and 31771875)+2 种基金the Fundamental Research Funds for the Central Universities of China(06500136)the Beijing Science&Technology Plan Program(Z191100004019005)。
文摘Sugar metabolism plays an essential role in plant male reproduction. Defects in sugar metabolism during anther and pollen development often result in genic male sterility(GMS). In this review, we summarize the recent progresses of the sugar metabolism-related GMS genes and their roles during plant anther and pollen development, including callose wall and primexine formation, intine development, pollen maturation and starch accumulation, anther dehiscence, and pollen germination and tube growth. We predict 112 putative sugar metabolic GMS genes in maize based on bioinformatics and RNA-seq analyses, and most of them have peak expression patterns during middle or late anther developmental stages.Finally, we outline the potential applications of sugar metabolic GMS genes in crop hybrid breeding and seed production. This review will deepen our understanding on sugar metabolic pathways in controlling pollen development and male fertility in plants.
基金supported by grants from the Key Science and Technology Planning Project of Guangzhou (Grant No. 201904020015)Science and Technology Program of Zhanjiang (Grant No. 2019A01003)+1 种基金Key Realm R&D Program of Guangdong Province (Grant No. 2018B020202011)Science and Technology Program of Guangzhou (Grant Nos. 202002020060, 201704020003 and 2014Y2-00164)
文摘Sugar composition not only affects fruit flavor but is also an important determinant of fruit taste and consumer preference.In this study,changes in the sugar content and sugar-metabolizing enzymes were investigated from different sections of various fruit development phases of‘Hongshuijing’pitaya(Hylocereus monacanthus).Genes related to sugar metabolism were also screened by transcriptome analyses.The results indicated that glucose was the major sugar in mature pitaya fruit,and was mainly regulated by vacuolar acid invertase(VAI)and sucrose synthase(SS)(degradative direction).Sugar accumulation varied in pulp between different sections of the pitaya fruit.VAI,neutral invertase(NI)and SS(degradative direction)are crucial enzymes for sugar accumulation in pitaya.The expression of 17 genes related to sucrose metabolism obtained from seven databases[NCBI non-redundant protein database(Nr),NCBI non-redundant nucleotide sequence database(Nt),EuKaryotic Orthologous Groups(KOG),The Protein Families(Pfam),Kyoto Encyclopedia of Genes and Genomes(KEGG),Swiss-prot,and Gene Ontology(GO)]were analyzed in different pitaya pulp sections.HpVAI1 had the highest relative expression level on the 29th day after pollination(DAP).Positive correlations were found between HpVAI1 expression and VAI activity;HpNI4 and NI activity;HpSS2,HpSS5,and SS activity(synthetic direction),indicating that HpVAI1,HpNI4,and HpSS2 and HpSS5 were involved in the regulation of VAI,NI,and SS(synthetic direction),respectively.HpVAI1 and HpNI4 regulated sucrose degradation and the accumulation of glucose and fructose,while HpSS2 and HpSS5 regulated sucrose synthesis.These results suggest that HpVAI1 plays a key role in sugar metabolism during fruit development of‘Hongshuijing’pitaya.The results of this study provide new information about sugar metabolism in pitaya fruit that could help improve fruit quality and the breeding of new cultivars.
基金supported by the Natural Science Foundation of Jiangsu Province,China(BK20180312)the Jiangsu Key Laboratory for the Research and Utilization of Plant Resources,China(JSPKLB201810)the Natural Science Foundation of Shanxi Province,China(201901D111230)。
文摘The steviol glycosides(SGs)in stevia(Stevia rebaudiana Bertoni)leaves are becoming increasingly valuable due to its high sweetness but low calorific value,which is driving the development of stevia commercial cultivation.Optimizing fertilization management can effectively increase SGs productivity,but knowledge on the relationship between potassium(K)fertilization and SGs production is still lacking.In this study,pot experiments were conducted in order to investigate the effect of K deficiency on SGs synthesis in stevia leaves,as well as the underlying mechanisms.Our results showed that when compared with standard K fertilization,K deficiency treatment has no significant effect on the biomass of stevia plant grown in a given soil with high K contents.However,K deficiency critically decreased leaf SGs contents as well as the expression of SGs synthesis-related genes.The contents of different sugar components decreased and the activities of sugar metabolism-related enzymes were inhibited under the K deficiency condition.Moreover,spraying sucrose on the leaves of stevia seedlings diminished the inhibitory effect caused by K deficiency.Our results also revealed the significant positive correlations between sucrose,glucose and SGs contents.Overall,our results suggest that K deficiency would suppress the synthesis of SGs in stevia leaves,and this effect may be mediated by the leaf sugar metabolism.Our findings provide new insights into the improvement of SGs production potential.
文摘The effect of NaCl with or without silicon on the growth and metabolism in rice seedlings cv. MTU1010 was studied. In these seedlings, the oxidative stress has been observed with NaCl treatments and the levels of proline, H<sub>2</sub>O<sub>2</sub> and malondialdehyde contents were increased whereas catalase activity was decreased. NaCl exposure at 25 mM, 50 mM and 100 mM concentrations in the test seedlings resulted in an increase in both reducing and non-reducing sugar content. There was a decrease in starch contents and the activity of starch phosphorylase was increased. NaCl stress also affected the activities of different carbohydrate metabolizing enzymes. The activities of sucrose synthase and sucrose phosphate synthase were increased, while the activity of acid invertase was decreased. Joint application of silicon with NaCl showed significant alterations on all parameters tested under the purview of NaCl treatment alone leading to better growth and metabolism in rice seedlings. Thus the use of silicon enriched fertilizers may help to grow healthy rice plants in NaCl rich soil.
文摘In this study,high performance liquid chromatography(HPLC)and RNA-seq transcriptome sequencing were used to study the changes in soluble sugar components and flavonoids in Prunus persica‘Jinxiangyu’at different developmental stages(20–90 d after flowering)and screen the key genes regulating the formation of soluble sugar and flavonoids in the fruits.The results showed that 60–85 d after flowering was the key stage of quality formation of Prunus persica‘Jinxiangyu’,and the content of soluble sugar,soluble solid,fructose,and sucrose in the fruit increased significantly during this period.The sugar content of ripe fruits was mainly fructose and sucrose.The content of kaempferol glycoside was low in the fruit.Quercetin glycoside content was higher in the young fruit stage and decreased with fruit maturity.There were no anthocyanin compounds in the fruit.The expression levels of genes involved in flavonoid metabolism(ANS,DFR,F3H,FLS,4CL1,etc.)were low in the fruit.A total of 181 differentially expressed genes were identified during fruit development to participate in five sugar metabolism pathways,among which the SDH gene had a higher expression level,which continuously rised in the later stage of fruit development.It mainly promoted the accumulation of fructose content in the later stage of fruit development.The expression levels of SPS1,SS,and SS1 genes were continuously up-regulated,which played a key role in sucrose regulation.The higher expression levels of SUS3 and INVA genes in the early stage of fruit development promoted the degradation of sucrose.
基金National Natural Science Foundation of China(31930086,32072637).
文摘Sugars are fundamental metabolites synthesized in leaves and further delivered to fruit in fruit crops.They not only provide"sweetness"as fruit quality traits,but also function as signaling molecules to modulate the responses of fruit to environmental stimuli.Therefore,the understanding to the molec-ular basis for sugar metabolism and transport is crucial for improving fruit quality and dissecting responses to abiotic/biotic factors.Here,we provide a review for mol ecular components involved in sugar metabolism and transport,crostalk with hormone signaling and the roles of sugars in responses to abiotic and biotic stresses.Moreover,we also envisage the strategies for optimizing sugar metabolism during fruit quality maintenance.
文摘Invertase （INV） hydrolyzes sucrose into glucose and fructose, thereby playing key roles in primary metabolism and plant development. Based on their pH optima and sub-cellular locations, INVs are categorized into cell wall, cytoplasmic, and vacuolar subgroups, abbreviated as CWlN, CIN, and VlN, respectively. The broad importance and implications of INVs in plant development and crop productivity have attracted enormous interest to examine INV function and regulation from multiple perspectives. Here, we review some exciting advances in this area over the last two decades, focusing on （1） new or emerging roles of INV in plant development and regulation at the post-translational level through interaction with inhibitors, （2） cross-talk between INV-mediated sugar signaling and hormonal control of development, and （3） sugar- and INV-mediated responses to drought and heat stresses and their impact on seed and fruit set. Finally, we discuss major questions arising from this new progress and outline future directions for unraveling mechanisms underlying INV-mediated plant development and their potential applications in plant biotechnology and agriculture.
基金supported by the National Natural Science Foundation of China(32170337,31870303)。
文摘Vitamin B(VB1),including thiamin,thiamin monophosphate(TMP),and thiamin pyrophosphate(TPP),is an essential micronutrient for all living organisms.Nevertheless,the precise function of VB1 in rice remains unclear.Here,we described a VB1 auxotrophic mutant,chlorotic lethal seedling(cles)from the mutation of OsTH1,which displayed collapsed chloroplast membrane system and decreased pigment content.OsTH1 encoded a phosphomethylpyrimidine kinase/thiamin-phosphate pyrophosphorylase,and was expressed in various tissues,especially in seedlings,leaves,and young panicles.The VB1 content in cles was markedly reduced,despite an increase in the expression of VB1 synthesis genes.The decreased TPP content affected the tricarboxylic acid cycle,pentose phosphate pathway,and de novo fatty acid synthesis,leading to a reduction in fatty acids(C16:0 and C18:0)and sugars(sucrose and glucose)of cles.Additionally,irregular expression of chloroplast membrane synthesis genes led to membrane collapse.We also found that alternative splicing and translation allowed OsTH1 to be localized to both chloroplast and cytosol.Our study revealed that OsTH1 was an essential enzyme in VB1 biosynthesis and played crucial roles in seedling growth and development by participating in fatty acid and sugar metabolism,providing new perspectives on VB1 function in rice.
基金supported by the Provincial Technology Innovation Program of Shandongan award from the Natural Science Foundation of Shandong Province(ZR2021ZD30)+2 种基金the Director’s Award from the Peking University Institute of Advanced Agricultural Sciences,the National Top Young Talents Program of Chinathe Boya Postdoctoral Program of Peking University,the National Key R&D Program of China(2019YFD1000200)the Youth Innovation Promotion Association CAS(2018376).
文摘Kiwifruit is a recently domesticated horticultural fruit crop with substantial economic and nutritional value,especially because of the high content of vitamin C in its fruit.In this study,we de novo assembled two telomere-to-telomere kiwifruit genomes from Actinidia chinensis var.‘Donghong’(DH)and Actinidia latifolia‘Kuoye’(KY),with total lengths of 608327852 and 640561626 bp for 29 chromosomes,respectively.With a burst of structural variants involving inversion,translocations,and duplications within 8.39 million years,the metabolite content of DH and KY exhibited differences in saccharides,lignans,and vitamins.A regulatory ERF098 transcription factor family has expanded in KY and Actinidia eriantha,both of which have ultra-high vitamin C content.With each assembly phased into two complete haplotypes,we identified allelic variations between two sets of haplotypes,leading to protein sequence variations in 26494 and 27773 gene loci and allele-specific expression of 4687 and 12238 homozygous gene pairs.Synchronized metabolome and transcriptome changes during DH fruit development revealed the same dynamic patterns in expression levels and metabolite contents;free fatty acids and flavonols accumulated in the early stages,but sugar substances and amino acids accumulated in the late stages.The AcSWEET9b gene that exhibits allelic dominance was further identified to positively correlate with high sucrose content in fruit.Compared with wild varieties and other Actinidia species,AcSWEET9b promoters were selected in red-flesh kiwifruits that have increased fruit sucrose content,providing a possible explanation on why red-flesh kiwifruits are sweeter.Collectively,these two gap-free kiwifruit genomes provide a valuable genetic resource for investigating domestication mechanisms and genome-based breeding of kiwifruit.
基金This work was supported by the National Key R&D Program of China(Grant No.2019YFA0906500)National Natural Science Foundation of China Project 31870472 and 31470123.
文摘Bumblebees play an important role in maintaining the balance of natural and agricultural ecosystems,and the characteristic gut microbiota of bumblebees exhibit significant mutualistic functions.China has the highest diversity of bumblebees;however,gut microbiota of Chinese bumblebees have mostly been investigated through cultureindependent studies.Here,we analyzed the gut communities of bumblebees from Sichuan,Yunnan,and Shaanxi provinces in China through 16S ribosomal RNA amplicon sequencing and bacterial isolation.It revealed that the bumblebees examined in this study harbored two gut enterotypes as previously reported:one is dominated by Gilliamella and Snodgrassella,and the other is distinguished by prevalent environmental species.The gut compositions obviously varied among different individual bees.We then isolated 325 bacterial strains and the comparative genomic analysis of Gillianiella strains revealed that galactose and pectin digestion pathways were conserved in strains from bumblebees,while genes for the utilization of arabinose,mannose,xylose,and rhamnose were mostly lost.Only two strains from the Chinese bumblebees possess the multidrug-resistant gene emrB,which is phylogenetically closely related to that from the symbionts of soil entomopathogenic nematode.In contrast,tetracycline-resistant genes were uniquely present in three strains from the USA.Our results illustrate the prevalence of strain-level variations in the metabolic potentials and the distributions of antibiotic-resistant genes in Chinese bumblebee gut bacteria.
