Glucosinolates(GSLs) are a group of nitrogen-and sulfur-containing secondary metabolites, synthesized primarily in members of the Brassicaceae family, that play an important role in food flavor, plant antimicrobial ac...Glucosinolates(GSLs) are a group of nitrogen-and sulfur-containing secondary metabolites, synthesized primarily in members of the Brassicaceae family, that play an important role in food flavor, plant antimicrobial activity, resistance to insect attack, stress tolerance, and human anti-cancer effects. As a sulfur-containing compound, glutathione has a strong connection with GSLs biosynthesis as a sulfur donor or redox system, and exists in reduced(glutathione;GSH) and oxidized(glutathione disulfide;GSSG) forms. However, the mechanism of GSH regulating GSLs biosynthesis remainds unclear. Hence, the exogenous therapy to pakchoi under normal growth condition and sulfur deficiency condition were conducted in this work to explore the relevant mechanism. The results showed that exogenous application of buthionine sulfoximine, an inhibitor of GSH synthesis, decreased the transcript levels of GSLs synthesis-related genes and transcription factors, as well as sulfur assimilation-related genes under the normal growth condition. Application of exogenous GSH inhibited the expression of GSLs synthesis-and sulfur assimilation-related genes under the normal condition, while the GSLs biosynthesis and the sulfur assimilation pathway were activated by exogenous application of GSH when the content of GSH in vivo of plants decreased owing to sulfur deficiency. Moreover,exogenous application of GSSG increased the transcript levels of GSLs synthesis-and sulfur assimilation-related genes under the normal growth condition and under sulfur deficiency. The present work provides new insights into the molecular mechanisms of GSLs biosynthesis underlying glutathione regulation.展开更多
Pakchoi(Brassica campestris L. ssp. chinensis) is an important leafy vegetable. Various light spectra, especially red and blue light, play vital roles in the regulation of nitrate metabolism. Information on the effect...Pakchoi(Brassica campestris L. ssp. chinensis) is an important leafy vegetable. Various light spectra, especially red and blue light, play vital roles in the regulation of nitrate metabolism. Information on the effects of red and blue light on nitrate metabolism at the transcriptome level in pakchoi is still limited, so this study used RNA sequencing technology to explore this molecular mechanism. Through pairwise comparisons with white LED light, 3 939 and 5 534 differentially expressed genes(DEGs) were identified under red and blue light, respectively. By Kyoto Encyclopedia of Genes and Genomes(KEGG) and Gene Ontology(GO) analyses, these unigenes were found to be involved in nitrate assimilation, plant-pathogen interaction, biosynthesis of secondary metabolites, and phenylpropanoid biosynthesis. The differential effects of light spectra on the nitrate concentration and metabolism-related enzyme activities were also confirmed at the physiological level. Several signal transduction modules, including Crys/Phys-COP1-HY5/HY5-like, were found to be involved in red and blue light-induced nitrate metabolism, and the transcript levels for this complex were consistent with the observed degree of nitrate assimilation. The expression patterns of 15 randomly selected DEGs were further validated using qPCR. Taken together, the results of this study could help improve our understanding of light spectrumregulated nitrate metabolism in pakchoi at the transcriptome level.展开更多
A pot experiment was carried out to study the effects of two amendments, lime and calcium magnesium phosphate, on the growth and Cd, Pb, Zn, Cu, Mn, Fe, N, P and K uptake of pakchoi (Brassica chinensis)in a Cd, Pb and...A pot experiment was carried out to study the effects of two amendments, lime and calcium magnesium phosphate, on the growth and Cd, Pb, Zn, Cu, Mn, Fe, N, P and K uptake of pakchoi (Brassica chinensis)in a Cd, Pb and Zn polluted acid soil in the southern part of China. The growth of pakchoi was apparently improved by lime and calcium magnesium phosphate application, the uptake of Cd, Pb, Cu and Zn by pakchoi was significantly depressed and the symptom caused by heavy metals pollution was eliminated.Meanwhile, the absorption of N, K and Mn was also inhibited by these amendments. Soil pH was the main factor controlling the uptake of the heavy metals by pakchoi. This suggests that lime and calcium magnesium phosphate could be used as effective amendments for eliminating the toxicity of heavy metals to the vegetable and inhibiting their absorption by the crop.展开更多
Two pot experiments with a completely random design and 4 replications were performed in a greenhouse to examine the response difference of 17 cultivars of pakchoi (Brassica chinensis L.) grown in a Cu-spiked and a cl...Two pot experiments with a completely random design and 4 replications were performed in a greenhouse to examine the response difference of 17 cultivars of pakchoi (Brassica chinensis L.) grown in a Cu-spiked and a clean soil to Cu.relatively tolerant. When the 17 cultivars of pakchoi grew in clean garden soil, the Cu concentrations in the aboveground part were positively correlated (r = 0.6693) with their root Cu concentrations. However, when they grew in the Cu-spiked soil a highly negative correlation coefficient (r = -0.5376) was obtained in the Cu concentration between the aboveground part and the root. This meant that the Cu tolerant cultivars had a weak ability to transfer Cu from their root to their aboveground part, and therefore stored much more Cu in their root than the Cu sensitive cultivars.展开更多
The dissipation of chlorpyrifos on pakchoi inside and outside greenhouse was studied. The decline curve of chlorpyrifos on pakchoi could be described as first-order kinetic. The experimental data showed that both the ...The dissipation of chlorpyrifos on pakchoi inside and outside greenhouse was studied. The decline curve of chlorpyrifos on pakchoi could be described as first-order kinetic. The experimental data showed that both the hermetic environment of greenhouse and season affected dissipation rates of chlorpyrifos on pakchoi. Chlorpyrifos declined faster outside greenhouse than inside greenhouse. Chlorpyrifos residues at pre-harvest time were below the maximum residue limits(MRLs) fixed in China, whereas the values inside greenhouse were higher than those outside greenhouse by almost 50%. The recommended pre-harvest time established under conditions of open field might not always fit to greenhouse production.展开更多
Different nitrogen(N) forms may cause changes in the metabolic profiles of plants. However, few studies have been conducted on the effects of amino acid-N on plant metabolic profiles. The main objective of this study ...Different nitrogen(N) forms may cause changes in the metabolic profiles of plants. However, few studies have been conducted on the effects of amino acid-N on plant metabolic profiles. The main objective of this study was to identify primary metabolites associated with amino acid-N(Gly, Gln and Ala) through metabolic profile analysis using gas chromatographymass spectrometry(GC-MS). Plants of pakchoi(Brassica campestris L. ssp. chinensis L.), Huawang and Wuyueman cultivars, were grown with different nitrogen forms(i.e., Gly, Gln, Ala, NO3--N, and N starvation) applied under sterile hydroponic conditions. The fresh weight and plant N accumulation of Huawang were greater than those of Wuyueman, which indicates that the former exhibited better N-use efficiency than the latter. The physiological performances of the applied N forms were generally in the order of NO3--N>Gln>Gly>Ala. The metabolic analysis of leaf polar extracts revealed 30 amino acid N-responsive metabolites in the two pakchoi cultivars, mainly consisting of sugars, amino acids, and organic acids. Changes in the carbon metabolism of pakchoi leaves under amino acid treatments occurred via the accumulation of fructose, glucose, xylose, and arabinose. Disruption of amino acid metabolism resulted in accumulation of endogenous Gly in Gly treatment, Pro in Ala treatment, and Asn in three amino acid(Gly, Gln and Ala) treatments. By contrast, the levels of endogenous Gln and Leu decreased. However, this reduction varied among cultivars and amino acid types. Amino acid-N supply also affected the citric acid cycle, namely, the second stage of respiration, where leaves in Gly, Gln and Ala treatments contained low levels of malic, citric and succinic acids compared with leaves in NO3--N treatments. No significant difference in the metabolic responses was observed between the two cultivars which differed in their capability to use N. The response of primary metabolites in pakchoi leaves to amino acid-N supply may serve an important function in pakchoi adaptation to amino acid-N sources.展开更多
Pakchoi,a popular leafy vegetable in China,is expected to be planted in plant factories with artificial lighting(PFALs).In order to examine the effects of different red and blue light ratios(R:B ratio)on growth,photos...Pakchoi,a popular leafy vegetable in China,is expected to be planted in plant factories with artificial lighting(PFALs).In order to examine the effects of different red and blue light ratios(R:B ratio)on growth,photosynthesis,and absorption spectrum of plant leaves,and to analyze the energy use efficiency,the pakchoi(Brassica Chinensis L.cv.Xiazhijiao)was cultivated hydroponically under white LEDs with R:B ratios of 0.9(L0.9)and 1.8(L1.8),white plus red LEDs with R:B ratios of 2.7(L2.7)and 4.0(L4.0)for 40 d,respectively.The results showed that the leaf length and width were significantly greater in the L0.9 treatment than in other treatments,and the dry weight per plant increased by over 33%when R:B ratio decreased from 4.0 to 0.9.The net photosynthesis rates of pakchoi leaves ranged from 9.2 to 9.6μmol/(m2·s)under different lighting conditions,which had no significant difference.The biggest difference in the spectrum absorptance of pakchoi leaves was expressed in green light waveband,and the highest absorption of plant leaves was under L0.9 and L1.8 treatments.The light energy use efficiency(LUE),photon yield(PY),and energy yield(EY)in L0.9 were over 25%higher than that in the other treatments,while there was no significant difference in the electrical energy use efficiency(EUE).In conclusion,an optimal light quality to cultivate pakchoi in PFALs was the white LEDs with R:B ratio of 0.9,and this finding could provide a promising lighting environment to hydroponic pakchoi yield and energy use efficiency.展开更多
The seed germination and seedling growth of pakchoi (Brassica campestris ssp. chinensis var.communis Tsen et Lee cv. Hanxiao) were not significantly inhibited until the concentration of NaCl was increased to150 mmol/L...The seed germination and seedling growth of pakchoi (Brassica campestris ssp. chinensis var.communis Tsen et Lee cv. Hanxiao) were not significantly inhibited until the concentration of NaCl was increased to150 mmol/L. Treatment of pakchoi seeds with exogenous 5-aminolevulinic acid (ALA), at concentrations ranging from 0.01 to 10.00 mg/L, promoted seed germination when seeds were stressed by salinity, whereas levulinic acid (LA), an inhibitor of ALA dehydrase, significantly inhibited seed germination and seedling growth, suggesting that metabolism of ALA into porphyrin compounds was necessary for seed germination and seedling growth. Determination of respiratory rate during seed germination showed that ALA increased seed respiration under both normal conditions and salt stress. Furthermore, salt stress decreased levels of endogenous ALA, as well as heme, in etiolated seedlings. More salt-tolerant cultivars of pakchoi contained higher relative levels of endogenous ALA and heme under conditions of salt stress.These results indicate that salt stress may inhibit the biosynthesis of endogenous ALA and then heme,which is necessary for seed germination, and treatment of seeds with exogenous ALA prior to germination may be associated with the biosynthesis of heme.展开更多
The selection and breeding of pollution-safe cultivars (PSCs) is a practicable and cost-effective approach to minimize the influx of heavy metal to the human food chain.In this study,both pot-culture and field experim...The selection and breeding of pollution-safe cultivars (PSCs) is a practicable and cost-effective approach to minimize the influx of heavy metal to the human food chain.In this study,both pot-culture and field experiments were conducted to identify and screen out cadmium pollution-safe cultivars (Cd-PSCs) from 50 pakchoi (Brassica rapa L.ssp.chinensis) cultivars for food safety.When treated with 1.0 or 2.5 mg/kg Cd,most of the pakchoi cultivars (>70%) showed greater or similar shoot biomass when compared with the control.This result indicates that pakchoi has a considerable tolerance to soil Cd stress.Cd concentrations in the shoot varied significantly (P<0.05) between cultivars:in two Cd treatments (1.0 and 2.5 mg/kg),the average values were 0.074 and 0.175 mg/kg fresh weight (FW),respectively.Cd concentrations in the shoots of 14 pakchoi cultivars were lower than 0.05 mg/kg FW.In pot-culture experiments,both enrichment factors (EFs) and translocation factors (TFs) of six pakchoi cultivars were lower than 1.0.The field studies further confirmed that the Hangzhouyoudonger,Aijiaoheiye 333,and Zaoshenghuajing cultivars are Cd-PSCs,and are therefore suitable for growth in low Cd-contaminated soils (≤1.2 mg/kg) without any risk to food safety.展开更多
基金funded by the National Natural Science Foundation of China (Grant Nos.31972394 and 31501748)。
文摘Glucosinolates(GSLs) are a group of nitrogen-and sulfur-containing secondary metabolites, synthesized primarily in members of the Brassicaceae family, that play an important role in food flavor, plant antimicrobial activity, resistance to insect attack, stress tolerance, and human anti-cancer effects. As a sulfur-containing compound, glutathione has a strong connection with GSLs biosynthesis as a sulfur donor or redox system, and exists in reduced(glutathione;GSH) and oxidized(glutathione disulfide;GSSG) forms. However, the mechanism of GSH regulating GSLs biosynthesis remainds unclear. Hence, the exogenous therapy to pakchoi under normal growth condition and sulfur deficiency condition were conducted in this work to explore the relevant mechanism. The results showed that exogenous application of buthionine sulfoximine, an inhibitor of GSH synthesis, decreased the transcript levels of GSLs synthesis-related genes and transcription factors, as well as sulfur assimilation-related genes under the normal growth condition. Application of exogenous GSH inhibited the expression of GSLs synthesis-and sulfur assimilation-related genes under the normal condition, while the GSLs biosynthesis and the sulfur assimilation pathway were activated by exogenous application of GSH when the content of GSH in vivo of plants decreased owing to sulfur deficiency. Moreover,exogenous application of GSSG increased the transcript levels of GSLs synthesis-and sulfur assimilation-related genes under the normal growth condition and under sulfur deficiency. The present work provides new insights into the molecular mechanisms of GSLs biosynthesis underlying glutathione regulation.
基金financially supported by the National Key Research and Development Program of China(2017YFB0403903)the Agricultural Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(ASTIP-CAAS,34-IUA-03)。
文摘Pakchoi(Brassica campestris L. ssp. chinensis) is an important leafy vegetable. Various light spectra, especially red and blue light, play vital roles in the regulation of nitrate metabolism. Information on the effects of red and blue light on nitrate metabolism at the transcriptome level in pakchoi is still limited, so this study used RNA sequencing technology to explore this molecular mechanism. Through pairwise comparisons with white LED light, 3 939 and 5 534 differentially expressed genes(DEGs) were identified under red and blue light, respectively. By Kyoto Encyclopedia of Genes and Genomes(KEGG) and Gene Ontology(GO) analyses, these unigenes were found to be involved in nitrate assimilation, plant-pathogen interaction, biosynthesis of secondary metabolites, and phenylpropanoid biosynthesis. The differential effects of light spectra on the nitrate concentration and metabolism-related enzyme activities were also confirmed at the physiological level. Several signal transduction modules, including Crys/Phys-COP1-HY5/HY5-like, were found to be involved in red and blue light-induced nitrate metabolism, and the transcript levels for this complex were consistent with the observed degree of nitrate assimilation. The expression patterns of 15 randomly selected DEGs were further validated using qPCR. Taken together, the results of this study could help improve our understanding of light spectrumregulated nitrate metabolism in pakchoi at the transcriptome level.
基金the National Natural Science Foundation of China(No.49671048) the Education Department of Fujian Province,China(No.K98025).
文摘A pot experiment was carried out to study the effects of two amendments, lime and calcium magnesium phosphate, on the growth and Cd, Pb, Zn, Cu, Mn, Fe, N, P and K uptake of pakchoi (Brassica chinensis)in a Cd, Pb and Zn polluted acid soil in the southern part of China. The growth of pakchoi was apparently improved by lime and calcium magnesium phosphate application, the uptake of Cd, Pb, Cu and Zn by pakchoi was significantly depressed and the symptom caused by heavy metals pollution was eliminated.Meanwhile, the absorption of N, K and Mn was also inhibited by these amendments. Soil pH was the main factor controlling the uptake of the heavy metals by pakchoi. This suggests that lime and calcium magnesium phosphate could be used as effective amendments for eliminating the toxicity of heavy metals to the vegetable and inhibiting their absorption by the crop.
文摘Two pot experiments with a completely random design and 4 replications were performed in a greenhouse to examine the response difference of 17 cultivars of pakchoi (Brassica chinensis L.) grown in a Cu-spiked and a clean soil to Cu.relatively tolerant. When the 17 cultivars of pakchoi grew in clean garden soil, the Cu concentrations in the aboveground part were positively correlated (r = 0.6693) with their root Cu concentrations. However, when they grew in the Cu-spiked soil a highly negative correlation coefficient (r = -0.5376) was obtained in the Cu concentration between the aboveground part and the root. This meant that the Cu tolerant cultivars had a weak ability to transfer Cu from their root to their aboveground part, and therefore stored much more Cu in their root than the Cu sensitive cultivars.
基金The National Natural Science Foundation of China(No. 20377036 30230250 and 30270880)+1 种基金 the Major State Basic Research Development Programme of China(No. 2002CB410806) the Natural Science Foundation of Zhejiang Province(No. 301050) and Hangzhou Committee of Science and Technology(No. 2002112A08)
文摘The dissipation of chlorpyrifos on pakchoi inside and outside greenhouse was studied. The decline curve of chlorpyrifos on pakchoi could be described as first-order kinetic. The experimental data showed that both the hermetic environment of greenhouse and season affected dissipation rates of chlorpyrifos on pakchoi. Chlorpyrifos declined faster outside greenhouse than inside greenhouse. Chlorpyrifos residues at pre-harvest time were below the maximum residue limits(MRLs) fixed in China, whereas the values inside greenhouse were higher than those outside greenhouse by almost 50%. The recommended pre-harvest time established under conditions of open field might not always fit to greenhouse production.
基金the National High-Tech R&D Program of China(863,2012AA101903)the Special Fund of China for Agro-Scientific Research in the Public Interest(200903056)
文摘Different nitrogen(N) forms may cause changes in the metabolic profiles of plants. However, few studies have been conducted on the effects of amino acid-N on plant metabolic profiles. The main objective of this study was to identify primary metabolites associated with amino acid-N(Gly, Gln and Ala) through metabolic profile analysis using gas chromatographymass spectrometry(GC-MS). Plants of pakchoi(Brassica campestris L. ssp. chinensis L.), Huawang and Wuyueman cultivars, were grown with different nitrogen forms(i.e., Gly, Gln, Ala, NO3--N, and N starvation) applied under sterile hydroponic conditions. The fresh weight and plant N accumulation of Huawang were greater than those of Wuyueman, which indicates that the former exhibited better N-use efficiency than the latter. The physiological performances of the applied N forms were generally in the order of NO3--N>Gln>Gly>Ala. The metabolic analysis of leaf polar extracts revealed 30 amino acid N-responsive metabolites in the two pakchoi cultivars, mainly consisting of sugars, amino acids, and organic acids. Changes in the carbon metabolism of pakchoi leaves under amino acid treatments occurred via the accumulation of fructose, glucose, xylose, and arabinose. Disruption of amino acid metabolism resulted in accumulation of endogenous Gly in Gly treatment, Pro in Ala treatment, and Asn in three amino acid(Gly, Gln and Ala) treatments. By contrast, the levels of endogenous Gln and Leu decreased. However, this reduction varied among cultivars and amino acid types. Amino acid-N supply also affected the citric acid cycle, namely, the second stage of respiration, where leaves in Gly, Gln and Ala treatments contained low levels of malic, citric and succinic acids compared with leaves in NO3--N treatments. No significant difference in the metabolic responses was observed between the two cultivars which differed in their capability to use N. The response of primary metabolites in pakchoi leaves to amino acid-N supply may serve an important function in pakchoi adaptation to amino acid-N sources.
基金This research was funded by the China Agriculture Research System of MOF and MARA(CARS-21)the National Key Research and Development Program of China(2017YFB0403901).
文摘Pakchoi,a popular leafy vegetable in China,is expected to be planted in plant factories with artificial lighting(PFALs).In order to examine the effects of different red and blue light ratios(R:B ratio)on growth,photosynthesis,and absorption spectrum of plant leaves,and to analyze the energy use efficiency,the pakchoi(Brassica Chinensis L.cv.Xiazhijiao)was cultivated hydroponically under white LEDs with R:B ratios of 0.9(L0.9)and 1.8(L1.8),white plus red LEDs with R:B ratios of 2.7(L2.7)and 4.0(L4.0)for 40 d,respectively.The results showed that the leaf length and width were significantly greater in the L0.9 treatment than in other treatments,and the dry weight per plant increased by over 33%when R:B ratio decreased from 4.0 to 0.9.The net photosynthesis rates of pakchoi leaves ranged from 9.2 to 9.6μmol/(m2·s)under different lighting conditions,which had no significant difference.The biggest difference in the spectrum absorptance of pakchoi leaves was expressed in green light waveband,and the highest absorption of plant leaves was under L0.9 and L1.8 treatments.The light energy use efficiency(LUE),photon yield(PY),and energy yield(EY)in L0.9 were over 25%higher than that in the other treatments,while there was no significant difference in the electrical energy use efficiency(EUE).In conclusion,an optimal light quality to cultivate pakchoi in PFALs was the white LEDs with R:B ratio of 0.9,and this finding could provide a promising lighting environment to hydroponic pakchoi yield and energy use efficiency.
基金the Overseas Scholarship Foundation of the Chinese Education Department，国家自然科学基金
文摘The seed germination and seedling growth of pakchoi (Brassica campestris ssp. chinensis var.communis Tsen et Lee cv. Hanxiao) were not significantly inhibited until the concentration of NaCl was increased to150 mmol/L. Treatment of pakchoi seeds with exogenous 5-aminolevulinic acid (ALA), at concentrations ranging from 0.01 to 10.00 mg/L, promoted seed germination when seeds were stressed by salinity, whereas levulinic acid (LA), an inhibitor of ALA dehydrase, significantly inhibited seed germination and seedling growth, suggesting that metabolism of ALA into porphyrin compounds was necessary for seed germination and seedling growth. Determination of respiratory rate during seed germination showed that ALA increased seed respiration under both normal conditions and salt stress. Furthermore, salt stress decreased levels of endogenous ALA, as well as heme, in etiolated seedlings. More salt-tolerant cultivars of pakchoi contained higher relative levels of endogenous ALA and heme under conditions of salt stress.These results indicate that salt stress may inhibit the biosynthesis of endogenous ALA and then heme,which is necessary for seed germination, and treatment of seeds with exogenous ALA prior to germination may be associated with the biosynthesis of heme.
基金Project supported by the National High-Tech R & D Program (863) of China (No.2009AA06Z316)the Science and Technology Commission of Zhejiang Province (No.2008C33047)the Fundamental Research Funds for the Central Universities,China
文摘The selection and breeding of pollution-safe cultivars (PSCs) is a practicable and cost-effective approach to minimize the influx of heavy metal to the human food chain.In this study,both pot-culture and field experiments were conducted to identify and screen out cadmium pollution-safe cultivars (Cd-PSCs) from 50 pakchoi (Brassica rapa L.ssp.chinensis) cultivars for food safety.When treated with 1.0 or 2.5 mg/kg Cd,most of the pakchoi cultivars (>70%) showed greater or similar shoot biomass when compared with the control.This result indicates that pakchoi has a considerable tolerance to soil Cd stress.Cd concentrations in the shoot varied significantly (P<0.05) between cultivars:in two Cd treatments (1.0 and 2.5 mg/kg),the average values were 0.074 and 0.175 mg/kg fresh weight (FW),respectively.Cd concentrations in the shoots of 14 pakchoi cultivars were lower than 0.05 mg/kg FW.In pot-culture experiments,both enrichment factors (EFs) and translocation factors (TFs) of six pakchoi cultivars were lower than 1.0.The field studies further confirmed that the Hangzhouyoudonger,Aijiaoheiye 333,and Zaoshenghuajing cultivars are Cd-PSCs,and are therefore suitable for growth in low Cd-contaminated soils (≤1.2 mg/kg) without any risk to food safety.
