Two homologous genes of the Arabidopsis C-repeat/dehydration-responsive element binding factors （CBF/ DREB1） transcriptional activator were isolated by RT-PCR from Chinese cabbage （Brassica pekinensis Rupr. cv. Qin...Two homologous genes of the Arabidopsis C-repeat/dehydration-responsive element binding factors （CBF/ DREB1） transcriptional activator were isolated by RT-PCR from Chinese cabbage （Brassica pekinensis Rupr. cv. Qinbai 5） and were designated as BcCBF1 and BcCBF2. Each encodes a putative CBF/DREB1 protein with an AP2 （Apetal2） DNA-bindlng domain, a putative nuclear localization signal, and a possible acidic activation domain. Deduced amino acid sequences show that BcCBF1 is very similar to the Arabidopsis CBF1, whereas BcCBF2 Is different in that it contains two extra regions of 24 and 20 amino acids in the acidic domain. The mRNA accumulation profiles indicated that the expression of BcCBF1 and BcCBF2 is strongly induced by cold treatment, but does not respond similarly to dehydration or abscisic acid （ABA） treatment. However, the cold-induced accumulation of BcCBF2 mRNA was rapid but short-lived compared with that of BcCBFI. The mRNA levels of both BcCBF1 and BcCBF2 were higher in leaves than in roots when plants were exposed to cold, whereas, salt stress caused higher accumulation of BcCBF2 mRNA in roots than in leaves, suggesting that the organ specificity of the gene expression of the BcCBFs is probably stress dependent. In addition, the accumulation of BcCBF1 and BcCBF2 mRNAs was greatly enhanced by light compared with darkness when seedlings were exposed to cold. It is concluded that the two BcCBF proteins may be involved in the process of plant response to cold stress through an ABA-independent pathway and that there is also a cross-talk between the light signaling conduction pathway and the cold response pathway in B. pekinensis as in Arabidopsis.展开更多
Low temperature stress is one of the most important factors limiting plant growth and geographical distribution.In order to adapt to low temperature,plants have evolved strategies to acquire cold tolerance,known as,co...Low temperature stress is one of the most important factors limiting plant growth and geographical distribution.In order to adapt to low temperature,plants have evolved strategies to acquire cold tolerance,known as,cold acclimation.Current molecular and genomic studies have reported that annual herbaceous and perennial woody plants share similar cold acclimation mechanisms.However,woody perennials also require extra resilience to survive cold winters.Thus,trees have acquired complex dynamic processes to control the development of dormancy and cold resistance,ensuring successful tolerance during the coldest winter season.In this review,we systemically described how woody plants perceive and transduce cold stress signals through a series of physiological changes such as calcium signaling,membrane lipid,and antioxidant changes altering downstream gene expression and epigenetic modification,ultimately bud dormancy.We extended the discussion and reviewed the processes endogenous phytohormones play in regulating the cold stress.We believe that this review will aid in the comprehension of underlying mechanisms in plant acclimation to cold stress.展开更多
基金Supported by the National Natural Science Foundation of China （30470277）, Gansu Key Technologies R ＆ D Program （GS022-A41-045）, Gansu Provincial Natural Science Foundation of China （ZS031-A25-039-D） and Gansu Agricultural Bio-technology R ＆ D Project.
文摘Two homologous genes of the Arabidopsis C-repeat/dehydration-responsive element binding factors （CBF/ DREB1） transcriptional activator were isolated by RT-PCR from Chinese cabbage （Brassica pekinensis Rupr. cv. Qinbai 5） and were designated as BcCBF1 and BcCBF2. Each encodes a putative CBF/DREB1 protein with an AP2 （Apetal2） DNA-bindlng domain, a putative nuclear localization signal, and a possible acidic activation domain. Deduced amino acid sequences show that BcCBF1 is very similar to the Arabidopsis CBF1, whereas BcCBF2 Is different in that it contains two extra regions of 24 and 20 amino acids in the acidic domain. The mRNA accumulation profiles indicated that the expression of BcCBF1 and BcCBF2 is strongly induced by cold treatment, but does not respond similarly to dehydration or abscisic acid （ABA） treatment. However, the cold-induced accumulation of BcCBF2 mRNA was rapid but short-lived compared with that of BcCBFI. The mRNA levels of both BcCBF1 and BcCBF2 were higher in leaves than in roots when plants were exposed to cold, whereas, salt stress caused higher accumulation of BcCBF2 mRNA in roots than in leaves, suggesting that the organ specificity of the gene expression of the BcCBFs is probably stress dependent. In addition, the accumulation of BcCBF1 and BcCBF2 mRNAs was greatly enhanced by light compared with darkness when seedlings were exposed to cold. It is concluded that the two BcCBF proteins may be involved in the process of plant response to cold stress through an ABA-independent pathway and that there is also a cross-talk between the light signaling conduction pathway and the cold response pathway in B. pekinensis as in Arabidopsis.
基金funded by the National Natural Science Foundation of China(No.31971682)the Research Startup Fund for High-Level and High-Educated Talents of Nanjing Forestry University.
文摘Low temperature stress is one of the most important factors limiting plant growth and geographical distribution.In order to adapt to low temperature,plants have evolved strategies to acquire cold tolerance,known as,cold acclimation.Current molecular and genomic studies have reported that annual herbaceous and perennial woody plants share similar cold acclimation mechanisms.However,woody perennials also require extra resilience to survive cold winters.Thus,trees have acquired complex dynamic processes to control the development of dormancy and cold resistance,ensuring successful tolerance during the coldest winter season.In this review,we systemically described how woody plants perceive and transduce cold stress signals through a series of physiological changes such as calcium signaling,membrane lipid,and antioxidant changes altering downstream gene expression and epigenetic modification,ultimately bud dormancy.We extended the discussion and reviewed the processes endogenous phytohormones play in regulating the cold stress.We believe that this review will aid in the comprehension of underlying mechanisms in plant acclimation to cold stress.
