Abscisic acid(ABA)is a plant hormone that plays an important role in plant development and abiotic stress.The 9-cis-epoxycarotenoid dioxygenase(NCED)is a key rate-limiting enzyme in the ABA biosynthetic pathway.The ph...Abscisic acid(ABA)is a plant hormone that plays an important role in plant development and abiotic stress.The 9-cis-epoxycarotenoid dioxygenase(NCED)is a key rate-limiting enzyme in the ABA biosynthetic pathway.The physiological and molecular mechanisms of NCED regulating plant development and abiotic stress tolerance have been reported in many plant species,but gene function of RiNCEDs in Rubus idaeus L.is rarely reported.In this study,the open reading frame(ORF)sequence of RiNCED2 in red raspberry fruit was isolated and the function of this gene under abiotic stress was investigated.While RiNCED2 was induced by cold,high salinity,drought and ABA,it was highly expressed in new leaves as measured by real-time qPCR.Overexpression of RiNCED2 in Arabidopsis under both high-salt and cold stress increased ABA content,demonstrating that RiNCED2 was involved in ABA biosynthesis.Meanwhile,the leaf wilting degree of transgenic Arabidopsis was less,while the content of malondialdehyde(MDA)was significantly reduced,and the chlorophyll content,proline content,peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)activities were significantly increased.These results indicated that overexpression of RiNCED2 enhanced the resistance of transgenic Arabidopsis to high salt and cold.展开更多
The mechanisms for fine-tuning ABA level related to grape berry ripening remain elusive. Here, transcription analysis showed that the mRNA expression level of 9-cis-epoxycarotenoid dioxygenase gene （VvNCED1） increas...The mechanisms for fine-tuning ABA level related to grape berry ripening remain elusive. Here, transcription analysis showed that the mRNA expression level of 9-cis-epoxycarotenoid dioxygenase gene （VvNCED1） increases first, rapidly in mesocarp before the onset of grape berry ripening. After VvNCED1 peaks its expression level, ABA content increases rapidly in mesocarp coupled with an increase in both soluble sugar content and pH value. On the onset of berry ripening, VvNCED1 transcripts decline rapidly to its lowest point, then increases slightly. Whereas, the mRNA expression level of B-glucosidase gene VvBGI, on the whole, increases constantly during grape berry ripening. During berry de-greening, ABA glucosyltransferase （VvGT） and ABA 8＇-hydroxylase （VvCYPI） equilibrate ABA level; during berry coloring-up, VvGT predominantly equilibrates ABA level, namely, the up-regulation of ABA level mainly leads from VvNCED1 and VvBG1 gene high expression; the down-regulation of ABA level leads mainly from VvCYP! transcript level both in ABA content- and developmental phase-dependence manner. In conclusion, our main results show that VvNCED1 and VvBG1 genes are closely related to grape berry ripening.展开更多
基金Supported by the Postdoctoral Scientific Research Development Fund of Heilongjiang Province,China(LBH-Z21119)the Natural Science Fund Joint Guidance Project of Heilongjiang Province(LH2020C009)Young Talent Project of Northeast Agricultural University(19QC06)。
文摘Abscisic acid(ABA)is a plant hormone that plays an important role in plant development and abiotic stress.The 9-cis-epoxycarotenoid dioxygenase(NCED)is a key rate-limiting enzyme in the ABA biosynthetic pathway.The physiological and molecular mechanisms of NCED regulating plant development and abiotic stress tolerance have been reported in many plant species,but gene function of RiNCEDs in Rubus idaeus L.is rarely reported.In this study,the open reading frame(ORF)sequence of RiNCED2 in red raspberry fruit was isolated and the function of this gene under abiotic stress was investigated.While RiNCED2 was induced by cold,high salinity,drought and ABA,it was highly expressed in new leaves as measured by real-time qPCR.Overexpression of RiNCED2 in Arabidopsis under both high-salt and cold stress increased ABA content,demonstrating that RiNCED2 was involved in ABA biosynthesis.Meanwhile,the leaf wilting degree of transgenic Arabidopsis was less,while the content of malondialdehyde(MDA)was significantly reduced,and the chlorophyll content,proline content,peroxidase(POD),catalase(CAT)and superoxide dismutase(SOD)activities were significantly increased.These results indicated that overexpression of RiNCED2 enhanced the resistance of transgenic Arabidopsis to high salt and cold.
基金This study is supported by China National Nattu-al Science Foundation （Project 31040006） and Beijing Natural Science Foundation and Scientific Research Key Program of Beijing Commission of Education （NO. KZ200910020001）.
文摘The mechanisms for fine-tuning ABA level related to grape berry ripening remain elusive. Here, transcription analysis showed that the mRNA expression level of 9-cis-epoxycarotenoid dioxygenase gene （VvNCED1） increases first, rapidly in mesocarp before the onset of grape berry ripening. After VvNCED1 peaks its expression level, ABA content increases rapidly in mesocarp coupled with an increase in both soluble sugar content and pH value. On the onset of berry ripening, VvNCED1 transcripts decline rapidly to its lowest point, then increases slightly. Whereas, the mRNA expression level of B-glucosidase gene VvBGI, on the whole, increases constantly during grape berry ripening. During berry de-greening, ABA glucosyltransferase （VvGT） and ABA 8＇-hydroxylase （VvCYPI） equilibrate ABA level; during berry coloring-up, VvGT predominantly equilibrates ABA level, namely, the up-regulation of ABA level mainly leads from VvNCED1 and VvBG1 gene high expression; the down-regulation of ABA level leads mainly from VvCYP! transcript level both in ABA content- and developmental phase-dependence manner. In conclusion, our main results show that VvNCED1 and VvBG1 genes are closely related to grape berry ripening.
