Plants are highly susceptible to abiotic stresses,particularly heat stress during the reproductive stage.However,the specific molecular mechanisms underlying this sensitivity remain largely unknown.In the current stud...Plants are highly susceptible to abiotic stresses,particularly heat stress during the reproductive stage.However,the specific molecular mechanisms underlying this sensitivity remain largely unknown.In the current study,we demonstrate that the Nuclear Transcription Factor,X-box Binding Protein 1-Like 1(NFXL1),directly regulates the expression of DEHYDRATION-RESPONSIVE ELEMENT-BINDING PROTEIN 2A(DREB2A),which is crucial for reproductive thermotolerance in Arabidopsis.NFXL1 is upregulated by heat stress,and its mutation leads to a reduction in silique length(seed number)under heat stress conditions.RNA-Seq analysis reveals that NFXL1 has a global impact on the expression of heat stress responsive genes,including DREB2A,Heat Shock Factor A3(HSFA3)and Heat Shock Protein 17.6(HSP17.6)in flower buds.Interestingly,NFXL1 is enriched in the promoter region of DREB2A,but not of either HSFA3 or HSP17.6.Further experiments using electrophoretic mobility shift assay have confirmed that NFXL1 directly binds to the DNA fragment derived from the DREB2A promoter.Moreover,effector-reporter assays have shown that NFXL1 activates the DREB2A promoter.The DREB2A mutants are also heat stress sensitive at the reproductive stage,and DEREB2A is epistatic to NFXL1 in regulating thermotolerance in flower buds.It is known that HSFA3,a direct target of DREB2A,regulates the expression of heat shock proteins genes under heat stress conditions.Thus,our findings establish NFXL1 as a critical upstream regulator of DREB2A in the transcriptional cassette responsible for heat stress responses required for reproductive thermotolerance in Arabidopsis.展开更多
Rice<b> </b><span style="font-family:Verdana;">is a major cereal crop providing food and energy to more than half of world’s population and drought is a challenging abiotic stress limiting...Rice<b> </b><span style="font-family:Verdana;">is a major cereal crop providing food and energy to more than half of world’s population and drought is a challenging abiotic stress limiting rice production</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> Engineering drought tolerance trait is a major bottle neck because of multigenic control and complex nature. Two promising candidate genes utilized in engineering drought tolerance include DREB2A transcription factor (a master regulator of downstream stress inducible genes) and APX (an important ROS scavenging enzyme). Overexpression of DREB genes ha</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> shown encouraging results but with </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">negative impact on plant morphology and production. Moreover, co-expression of DREB2A and APX genes</span><span style="font-family:Verdana;">’</span><span style="font-family:Verdana;"> influence on drought stress has not been studied. Hence, in the present study</span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> overexpression of single genes DREB2A or APX and co-expression of these genes were studied for enhancement of drought tolerance in indica rice. Both genes under control of CaMV 35S promoter were transferred by </span><i><span style="font-family:Verdana;">Agrobacterium</span></i><span style="font-family:Verdana;"> transformation into rice variety BPT5204 popular for slender grains in South India. Confirmation of T-DNA integration into rice genome was done with PCR analysis of transgenes. Homozygous transgenic lines of DREB2A, </span><span><span style="font-family:Verdana;">APX and DREB2A-APX generated in T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> generation were evaluated for</span></span><span style="font-family:Verdana;"> drought tolerance during s展开更多
文摘植物的DREB2转录因子具有抗旱、抗盐碱的功能。对小麦族赖草属的14个物种的DREB2基因进行了克隆、测序和比对分析。结果表明:(1)14个赖草属植物的DREB2基因序列和氨基酸序列相对保守,总相似度分别为98.05%和97.78%;(2)Leymus mollis的DREB2基因在编码区有3 bp CTT的缺失;(3)14条DREB2基因序列共发现79个SNP,SNP发生频率为1SNP/10.6 bp;(4)进化树分析显示DREB2基因能把14个赖草属物种很好的分开。
基金supported by a National Natural Science Foundation of China(31625004).
文摘Plants are highly susceptible to abiotic stresses,particularly heat stress during the reproductive stage.However,the specific molecular mechanisms underlying this sensitivity remain largely unknown.In the current study,we demonstrate that the Nuclear Transcription Factor,X-box Binding Protein 1-Like 1(NFXL1),directly regulates the expression of DEHYDRATION-RESPONSIVE ELEMENT-BINDING PROTEIN 2A(DREB2A),which is crucial for reproductive thermotolerance in Arabidopsis.NFXL1 is upregulated by heat stress,and its mutation leads to a reduction in silique length(seed number)under heat stress conditions.RNA-Seq analysis reveals that NFXL1 has a global impact on the expression of heat stress responsive genes,including DREB2A,Heat Shock Factor A3(HSFA3)and Heat Shock Protein 17.6(HSP17.6)in flower buds.Interestingly,NFXL1 is enriched in the promoter region of DREB2A,but not of either HSFA3 or HSP17.6.Further experiments using electrophoretic mobility shift assay have confirmed that NFXL1 directly binds to the DNA fragment derived from the DREB2A promoter.Moreover,effector-reporter assays have shown that NFXL1 activates the DREB2A promoter.The DREB2A mutants are also heat stress sensitive at the reproductive stage,and DEREB2A is epistatic to NFXL1 in regulating thermotolerance in flower buds.It is known that HSFA3,a direct target of DREB2A,regulates the expression of heat shock proteins genes under heat stress conditions.Thus,our findings establish NFXL1 as a critical upstream regulator of DREB2A in the transcriptional cassette responsible for heat stress responses required for reproductive thermotolerance in Arabidopsis.
文摘Rice<b> </b><span style="font-family:Verdana;">is a major cereal crop providing food and energy to more than half of world’s population and drought is a challenging abiotic stress limiting rice production</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> Engineering drought tolerance trait is a major bottle neck because of multigenic control and complex nature. Two promising candidate genes utilized in engineering drought tolerance include DREB2A transcription factor (a master regulator of downstream stress inducible genes) and APX (an important ROS scavenging enzyme). Overexpression of DREB genes ha</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> shown encouraging results but with </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">negative impact on plant morphology and production. Moreover, co-expression of DREB2A and APX genes</span><span style="font-family:Verdana;">’</span><span style="font-family:Verdana;"> influence on drought stress has not been studied. Hence, in the present study</span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> overexpression of single genes DREB2A or APX and co-expression of these genes were studied for enhancement of drought tolerance in indica rice. Both genes under control of CaMV 35S promoter were transferred by </span><i><span style="font-family:Verdana;">Agrobacterium</span></i><span style="font-family:Verdana;"> transformation into rice variety BPT5204 popular for slender grains in South India. Confirmation of T-DNA integration into rice genome was done with PCR analysis of transgenes. Homozygous transgenic lines of DREB2A, </span><span><span style="font-family:Verdana;">APX and DREB2A-APX generated in T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> generation were evaluated for</span></span><span style="font-family:Verdana;"> drought tolerance during s
