Cold stress adversely affects rice growth,particularly at the early vegetative growth stage.In higher plants,nitrogen metabolism plays a central role in amino acid metabolism,plant defense mechanisms and productivity....Cold stress adversely affects rice growth,particularly at the early vegetative growth stage.In higher plants,nitrogen metabolism plays a central role in amino acid metabolism,plant defense mechanisms and productivity.This report investigated the effects of cold stress and supplementalγ-aminobutyric acid(GABA)under cold stress on nitrogen metabolism in rice seedlings.Cold stress resulted in a greater increase in the transformation to NH_(4)^(+)by nitrate reductase(NR)in roots,it further resulted in lower levels of NO_(3)^(-)content in roots,weakened glutamine glutamate(GOGAT/GS)pathway and elevated glutamate dehydrogenase(GDH)pathway of rice seedlings.Whereas,compared with cold stress,supplementation of GABA(2.5 mmol·L^(-1))could increase relative water content(79.43%)and biomass(34.15%)of rice seedlings.GABA could act as an amplifier of stress signal conduction/transduction to increase NR activity and promote NO_(3)^(-)assimilation in leaves.In addition,GABA elicited the Ca^(2+)signaling pathway which could promote the GDH pathway and GABA shunt,increase the activities of GS and GDH,and the expression of OsGAD2 and OsGDH family.The GABA might increase the ratio of the Glu family and avoid NH4+toxicity in order to raise the concentration of organic compounds and alleviate the harmful consequences of cold stress.Based on these observations,this study proposed that GABA mediated cold tolerance in rice seedlings by activating Ca^(2+)burst and subsequent crosstalk among Ca^(2+)signaling,GDH pathway and GABA shunt.展开更多
Present study was conducted to characterise ten rice(Oryza sativa L.) cultivars viz. IET-23466, Dhan-201, IET-23448, MAS-946, IET-23445, IET-23463, IET-23455, PR-123, PR-115 and IET-23449 based on antioxidants(total p...Present study was conducted to characterise ten rice(Oryza sativa L.) cultivars viz. IET-23466, Dhan-201, IET-23448, MAS-946, IET-23445, IET-23463, IET-23455, PR-123, PR-115 and IET-23449 based on antioxidants(total phenolics, flavonols and tannins), bioactive compounds(phytic acid, gamma amino butyric acid, tocopherol and reduced ascorbate) and antioxidant activity(1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, hydroxyl radical scavenging activity, free radical antioxidant power and total reducing power) with an aim to identify cultivars containing higher health promoting components after germination. Three cultivars IET-23466, IET-23463 and PR-123 performed better as revealed by higher level of antioxidants, bioactive compounds and antioxidant activity before and after germination. Three cultivars MAS-946, IET-23445 and IET-23449 had moderate level of antioxidants, bioactive compounds and antioxidant activity. Four cultivars Dhan-201, IET-23448, IET-23455 and PR-115 performed intermediately. Strong positive correlation was observed among total phenolics and the antioxidant activity. Phytic acid was found to be negatively correlated to the antioxidant activity. Our results highlighted that cultivars IET-23466, IET-23463 and PR-123 hold great potential after germination and would open up a useful opportunity for the functional food industry, and consumption of these cultivars after germination would afford health benefits to consumers since they contain higher level of antioxidants.展开更多
We successfully identified a novel and unique OsbZIP transcription factor,OsbZIP09,whose mutants exhibited longer seeds and less severe pre-harvest sprouting than the wild type,but shared similar germination rate as t...We successfully identified a novel and unique OsbZIP transcription factor,OsbZIP09,whose mutants exhibited longer seeds and less severe pre-harvest sprouting than the wild type,but shared similar germination rate as the wild type under normal germination conditions.The expression of OsbZIP09 was induced by abscisic acid(ABA)and declined as the germination process.As a nucleus-localized transcription factor,the conserved binding motif of OsbZIP09 was identified via DNA affinity purification sequencing technique.Further evidences indicated that OsbZIP09 directly enhanced the expression of ABA catabolism gene ABA8ox1,thus reducing ABA accumulation.In addition,OsbZIP09 also directly bound to the promoter of LEA3 gene to inhibit its expression,thus further alleviating the suppressive effect of ABA on seed germination.These results demonstrated that OsbZIP09 likely functions as a brake of the ABA pathway to attenuate the inhibitory effect of ABA on rice seed germination via dual strategies.展开更多
Brown rice was treated by segmented moisture conditioning to reach the suitable water content and aerated with air for germination.The effects of germination and aeration treatment on theγ-aminobutyric acid(GABA)cont...Brown rice was treated by segmented moisture conditioning to reach the suitable water content and aerated with air for germination.The effects of germination and aeration treatment on theγ-aminobutyric acid(GABA)content in germinated brown rice were studied.The results showed that the germination rate,glutamic acid,glutamate decarboxylase activity and GABA content in germinated brown rice increased significantly and then decreased with the increase of germination and aeration treatment parameters.Correlation analysis also revealed that there was a significant positive correlation between GABA accumulation and glutamic acid content,glutamate decarboxylase activity.These results suggested that the aeration treatment during germination following segmented moisture conditioning could contribute to a high GABA content of germinated brown rice.展开更多
Aromatic rice belongs to a small but important sub-group of rice,which is highly regarded for its excellent aroma and superior grain quality.Aromatic rice,especially Basmati-and Jasmine-type rice,is being traded at a ...Aromatic rice belongs to a small but important sub-group of rice,which is highly regarded for its excellent aroma and superior grain quality.Aromatic rice,especially Basmati-and Jasmine-type rice,is being traded at a high price in the local and global markets.Genetically,rice aroma is a phenotypical expression of spontaneous recessive mutations of the OsBadh2 gene(also known as fgr/badh2/osbadh2/os2AP gene).These mutations inhibit the flow ofγ-aminobutyraldehyde(GAB-ald)toγ-aminobutyric acid(GABA),and consequently,the accumulated GAB-ald is diverted to a potent flavour component 2-acetyl-1-pyrroline(2AP)by a non-enzymatic reaction with methylglyoxal.The natural incidence of non-functional osbadh2 mutation along with selection and nursing by the farmer from the ancient time makes rice aroma as a prominent natural gift.As GABA and methylglyoxal play significant roles in stress tolerance,and their biosynthesis is strictly regulated in rice plants,the accumulation of 2AP in aromatic rice depends on the interaction of various genetic and environmental factors,and its production may come at some costs of sacrificing tolerance.This review focused on some potential underlying genes in the 2AP and GABA biosynthesis pathways,and analyzed most aspects of aroma formation in rice,and summarized the molecular mechanism of aroma production together with its genetic and non-genetic influencing factors.The present review also stated approaches to produce high-quality aromatic rice via developing novel cultivars and with good agronomic knowledge-based practice.展开更多
Seed germination of plants with various acid-resis tance display different responses to acid rain.To understand the reason why such differences occur,the effects of sim ulated acid rain(pH 2.5-5.0)on the activities of...Seed germination of plants with various acid-resis tance display different responses to acid rain.To understand the reason why such differences occur,the effects of sim ulated acid rain(pH 2.5-5.0)on the activities of peroxidase(POD)and catalase(CAT)during sced ger-mination of rice(O.sativa),wheat(T.aestivurm),and rape(B.chinensis var.oleifera)were investigated.R cesults indi-cated that the maximum change in activities of CAT and POD by acid rain treatment with different acidity and time in relation to the referent treatment without acid rain,was in the order:rice(28.8%,31.7%)<wheat(34.7%,48.3%)<rape(79.3%,50.0%).The pH level for which the treatment with acid rain did not cause signif-cant difference(p<0.05)was in the order:rice(3.5)>wheat(4.0)>rape(5.0).Moreover,the change in activity of POD was higher than that of CAT,which showed that POD was more sensitive to acid rain stress than CAT.The difference in the ability of POD and CAT in removing free radicals was one reason why the germina-tion indexes of these three species behaved differently.展开更多
The objective of this study was to analyze the content ofγ-aminobutyric acid(GABA)in germinated brown rice(GBR)by using near-infrared spectroscopy(NIRS)and the pretreatment method of wavelet de-noising(WD).The predic...The objective of this study was to analyze the content ofγ-aminobutyric acid(GABA)in germinated brown rice(GBR)by using near-infrared spectroscopy(NIRS)and the pretreatment method of wavelet de-noising(WD).The prediction accuracy of the NIRS model established by the Daubechies5 wavelet basis function at 3 level denoising treatment is the highest,the correlation coefficient for calibration(rc)is 0.931,the root mean square error of calibration(RMSEC)is 0.4038 mg/100 g,the Bias of calibration is 0.006,the correlation coefficient for prediction(rp)is 0.916,the root mean square error of prediction(RMSEP)is 0.4329 mg/100 g,the Bias of prediction is 0.010,and the ratio of performance to deviation(RPD)is 4.911.Results showed that the predicted and actual values had high correlation.Therefore,these results indicate that the NIRS model treated by WD is feasible to detect GABA content in GBR rapidly and nondestructively.展开更多
基金Supported by the National Natural Science Foundation of China(32301935)the Heilongjiang Province Natural Science Foundation Project(LH2020C005)+1 种基金the Postdoctoral Fund to Research Start-up of Heilongjiang Province(LBH-Q21077)Heilongjiang Province Applied Technology Research and Development Plan Project(GA20B101)。
文摘Cold stress adversely affects rice growth,particularly at the early vegetative growth stage.In higher plants,nitrogen metabolism plays a central role in amino acid metabolism,plant defense mechanisms and productivity.This report investigated the effects of cold stress and supplementalγ-aminobutyric acid(GABA)under cold stress on nitrogen metabolism in rice seedlings.Cold stress resulted in a greater increase in the transformation to NH_(4)^(+)by nitrate reductase(NR)in roots,it further resulted in lower levels of NO_(3)^(-)content in roots,weakened glutamine glutamate(GOGAT/GS)pathway and elevated glutamate dehydrogenase(GDH)pathway of rice seedlings.Whereas,compared with cold stress,supplementation of GABA(2.5 mmol·L^(-1))could increase relative water content(79.43%)and biomass(34.15%)of rice seedlings.GABA could act as an amplifier of stress signal conduction/transduction to increase NR activity and promote NO_(3)^(-)assimilation in leaves.In addition,GABA elicited the Ca^(2+)signaling pathway which could promote the GDH pathway and GABA shunt,increase the activities of GS and GDH,and the expression of OsGAD2 and OsGDH family.The GABA might increase the ratio of the Glu family and avoid NH4+toxicity in order to raise the concentration of organic compounds and alleviate the harmful consequences of cold stress.Based on these observations,this study proposed that GABA mediated cold tolerance in rice seedlings by activating Ca^(2+)burst and subsequent crosstalk among Ca^(2+)signaling,GDH pathway and GABA shunt.
文摘Present study was conducted to characterise ten rice(Oryza sativa L.) cultivars viz. IET-23466, Dhan-201, IET-23448, MAS-946, IET-23445, IET-23463, IET-23455, PR-123, PR-115 and IET-23449 based on antioxidants(total phenolics, flavonols and tannins), bioactive compounds(phytic acid, gamma amino butyric acid, tocopherol and reduced ascorbate) and antioxidant activity(1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, hydroxyl radical scavenging activity, free radical antioxidant power and total reducing power) with an aim to identify cultivars containing higher health promoting components after germination. Three cultivars IET-23466, IET-23463 and PR-123 performed better as revealed by higher level of antioxidants, bioactive compounds and antioxidant activity before and after germination. Three cultivars MAS-946, IET-23445 and IET-23449 had moderate level of antioxidants, bioactive compounds and antioxidant activity. Four cultivars Dhan-201, IET-23448, IET-23455 and PR-115 performed intermediately. Strong positive correlation was observed among total phenolics and the antioxidant activity. Phytic acid was found to be negatively correlated to the antioxidant activity. Our results highlighted that cultivars IET-23466, IET-23463 and PR-123 hold great potential after germination and would open up a useful opportunity for the functional food industry, and consumption of these cultivars after germination would afford health benefits to consumers since they contain higher level of antioxidants.
基金supported by the National Training Programs of Innovation and Entrepreneurship for Undergraduates,Science Fund for Distinguished Young Scholars of Jiangsu Province,China(Grant No.BK20200045)the Priority Academic Program Development of Jiangsu Higher Education Institutions Program,China.
文摘We successfully identified a novel and unique OsbZIP transcription factor,OsbZIP09,whose mutants exhibited longer seeds and less severe pre-harvest sprouting than the wild type,but shared similar germination rate as the wild type under normal germination conditions.The expression of OsbZIP09 was induced by abscisic acid(ABA)and declined as the germination process.As a nucleus-localized transcription factor,the conserved binding motif of OsbZIP09 was identified via DNA affinity purification sequencing technique.Further evidences indicated that OsbZIP09 directly enhanced the expression of ABA catabolism gene ABA8ox1,thus reducing ABA accumulation.In addition,OsbZIP09 also directly bound to the promoter of LEA3 gene to inhibit its expression,thus further alleviating the suppressive effect of ABA on seed germination.These results demonstrated that OsbZIP09 likely functions as a brake of the ABA pathway to attenuate the inhibitory effect of ABA on rice seed germination via dual strategies.
基金The authors acknowledge that this work was financially supported by the Fundamental Research Funds for the Central Universities(2662020GXPY017,2662015QD043)Opening Subject for Key Laboratory of Modern Agriculture,Tarim University(TDNG20160102)for financial support and all of the persons who assisted in this writing.
文摘Brown rice was treated by segmented moisture conditioning to reach the suitable water content and aerated with air for germination.The effects of germination and aeration treatment on theγ-aminobutyric acid(GABA)content in germinated brown rice were studied.The results showed that the germination rate,glutamic acid,glutamate decarboxylase activity and GABA content in germinated brown rice increased significantly and then decreased with the increase of germination and aeration treatment parameters.Correlation analysis also revealed that there was a significant positive correlation between GABA accumulation and glutamic acid content,glutamate decarboxylase activity.These results suggested that the aeration treatment during germination following segmented moisture conditioning could contribute to a high GABA content of germinated brown rice.
基金the Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, China for providing postdoctoral fellowship, facilities and supports during this research.
文摘Aromatic rice belongs to a small but important sub-group of rice,which is highly regarded for its excellent aroma and superior grain quality.Aromatic rice,especially Basmati-and Jasmine-type rice,is being traded at a high price in the local and global markets.Genetically,rice aroma is a phenotypical expression of spontaneous recessive mutations of the OsBadh2 gene(also known as fgr/badh2/osbadh2/os2AP gene).These mutations inhibit the flow ofγ-aminobutyraldehyde(GAB-ald)toγ-aminobutyric acid(GABA),and consequently,the accumulated GAB-ald is diverted to a potent flavour component 2-acetyl-1-pyrroline(2AP)by a non-enzymatic reaction with methylglyoxal.The natural incidence of non-functional osbadh2 mutation along with selection and nursing by the farmer from the ancient time makes rice aroma as a prominent natural gift.As GABA and methylglyoxal play significant roles in stress tolerance,and their biosynthesis is strictly regulated in rice plants,the accumulation of 2AP in aromatic rice depends on the interaction of various genetic and environmental factors,and its production may come at some costs of sacrificing tolerance.This review focused on some potential underlying genes in the 2AP and GABA biosynthesis pathways,and analyzed most aspects of aroma formation in rice,and summarized the molecular mechanism of aroma production together with its genetic and non-genetic influencing factors.The present review also stated approaches to produce high-quality aromatic rice via developing novel cultivars and with good agronomic knowledge-based practice.
基金This work was supported by the Foundation of State Planning Committee(No.GJX01100626)the Foundation of Science and Technology Committee of Jiangsu Province(Grant No.BG2001045)the Foundation from Key Laboratory of Industrial Biotechnology of Ministry of Education,Jiangnan University of China.
文摘Seed germination of plants with various acid-resis tance display different responses to acid rain.To understand the reason why such differences occur,the effects of sim ulated acid rain(pH 2.5-5.0)on the activities of peroxidase(POD)and catalase(CAT)during sced ger-mination of rice(O.sativa),wheat(T.aestivurm),and rape(B.chinensis var.oleifera)were investigated.R cesults indi-cated that the maximum change in activities of CAT and POD by acid rain treatment with different acidity and time in relation to the referent treatment without acid rain,was in the order:rice(28.8%,31.7%)<wheat(34.7%,48.3%)<rape(79.3%,50.0%).The pH level for which the treatment with acid rain did not cause signif-cant difference(p<0.05)was in the order:rice(3.5)>wheat(4.0)>rape(5.0).Moreover,the change in activity of POD was higher than that of CAT,which showed that POD was more sensitive to acid rain stress than CAT.The difference in the ability of POD and CAT in removing free radicals was one reason why the germina-tion indexes of these three species behaved differently.
基金The authors express their acknowledgment to the National Natural Science Foundation of China(Grant No.32001423)Natural Science Foundation of Hubei Province(Grant No.2020CFB471)+1 种基金Fundamental Research Funds for the Central Universities(Grant No.2662020GXPY017)Opening Subject for Key Laboratory of Modern Agriculture,Tarim University(Grant No.TDNG2021104)for financial support and all of the persons who assisted in this writing.
文摘The objective of this study was to analyze the content ofγ-aminobutyric acid(GABA)in germinated brown rice(GBR)by using near-infrared spectroscopy(NIRS)and the pretreatment method of wavelet de-noising(WD).The prediction accuracy of the NIRS model established by the Daubechies5 wavelet basis function at 3 level denoising treatment is the highest,the correlation coefficient for calibration(rc)is 0.931,the root mean square error of calibration(RMSEC)is 0.4038 mg/100 g,the Bias of calibration is 0.006,the correlation coefficient for prediction(rp)is 0.916,the root mean square error of prediction(RMSEP)is 0.4329 mg/100 g,the Bias of prediction is 0.010,and the ratio of performance to deviation(RPD)is 4.911.Results showed that the predicted and actual values had high correlation.Therefore,these results indicate that the NIRS model treated by WD is feasible to detect GABA content in GBR rapidly and nondestructively.
