水稻黄绿叶突变会显著影响水稻产量和稻米品质.研究黄绿叶突变体叶绿素变化机理对选育高光效品种,促进水稻增产具有重要意义.本研究以甲基磺酸乙酯(ethylmethylsulfone,EMS)诱变处理粳稻云引(YY)后发现的一个黄绿叶突变体w08(YGL)为材料...水稻黄绿叶突变会显著影响水稻产量和稻米品质.研究黄绿叶突变体叶绿素变化机理对选育高光效品种,促进水稻增产具有重要意义.本研究以甲基磺酸乙酯(ethylmethylsulfone,EMS)诱变处理粳稻云引(YY)后发现的一个黄绿叶突变体w08(YGL)为材料,研究叶色突变对主要农艺性状、叶绿素含量、光合参数变化、水稻生理及亚显微结构的影响,并对该突变性状进行遗传分析、基因定位和功能验证.研究表明,突变体全生育期均表现为黄绿色.与野生型云引(YY)相比,突变体w08单株有效穗、结实率、千粒重分别降低46.7%、50.1%和18.3%,叶绿素a、叶绿素b和类胡萝卜素含量分别下降41.2%、98.7%、17.5%.光合速率检测结果表明,突变体净光合速率(Pn)显著降低,而细胞间CO_(2)(Ci)显著增加.对叶片叶绿体进行超微结构电子显微镜观察,结果发现,叶绿体内的类囊体基粒片层数目在突变体中明显减少.遗传分析结果表明,突变体黄绿叶性状为单基因遗传,受一对隐性核基因控制.利用突变体与雷蒙特(Lemont)杂交构建F2遗传群体,将该基因定位在10号染色体长臂GL8和T258两个标记之间,物理距离为60.2 kb,该区间包含14个候选基因.基因测序发现,该区间内的编码叶绿素酸酯氧化酶1(chlorophyllide a oxygenase1)蛋白的候选基因OsCAO1编码区CDS序列第957位碱基发生突变,形成一个终止密码子,使蛋白翻译提前终止.通过构建过表达和敲除载体进行转基因功能验证,进一步证实了OsCAO1基因功能.分析突变体中的激素含量和分蘖调控相关基因的表达,结果表明,突变体中水稻分蘖相关基因表达水平明显下降,生长素合成基因表达水平显著提高,水稻分蘖芽的生长素含量显著提高,从而证实OsCAO1基因突变抑制了水稻分蘖生长,使单株有效穗显著减少.展开更多
在广谱抗稻瘟病品种云引与普感稻瘟病品种丽江新团黑谷(Lijiangxintuanheigu,LTH)构建的近等基因系抗、感病子代基因组重测序的差异基因中,从与免疫应答(immune response)相关的分类单元里得到8个基因序列有差异的基因.它们都为编码富...在广谱抗稻瘟病品种云引与普感稻瘟病品种丽江新团黑谷(Lijiangxintuanheigu,LTH)构建的近等基因系抗、感病子代基因组重测序的差异基因中,从与免疫应答(immune response)相关的分类单元里得到8个基因序列有差异的基因.它们都为编码富含亮氨酸重复序列的类受体蛋白激酶基因,并聚集于11号染色体的邻近位置,且与已知的白叶枯病抗性基因Xa21具有一定同源性.为进一步探究这些类受体蛋白激酶类基因在稻瘟病抗性中可能发挥的功能,我们分析了这些基因的结构、进化及抗感子代间的序列差异类型,同时还分别采用离体和喷雾接菌的方式对云引和LTH进行稻瘟病接种并取样.通过实时荧光定量PCR(quantitative real time polymerase chain reaction,q RT-PCR)发现,部分基因能受到稻瘟病菌的诱导,推测它们可能在水稻对抗稻瘟病病菌中发挥一定作用,为进一步挖掘稻瘟病相关抗性基因奠定基础.展开更多
Plants usually keep resistance(R)proteins in a static state under normal conditions to avoid autoimmunity and save energy for growth,but R proteins can be rapidly activated upon perceiving pathogen invasion.Pib,the fi...Plants usually keep resistance(R)proteins in a static state under normal conditions to avoid autoimmunity and save energy for growth,but R proteins can be rapidly activated upon perceiving pathogen invasion.Pib,the first cloned blast disease R gene in rice,encoding a nucleotide-binding leucine-rich repeat(NLR)protein,mediates resistance to the blast fungal(Magnaporthe oryzae)isolates carrying the avirulence gene AvrPib.However,the molecular mechanisms about how Pib recognizes AvrPib and how it is inactivated and activated remain largely unclear.In this study,through map-based cloning and CRISPR-Cas9 gene editing,we proved that Pib contributes to the blast disease resistance of rice cultivar Yunyin(YY).Furthermore,an SH3 domain-containing protein,SH3P2,was found to associate with Pib mainly at clathrin-coated vesicles in rice cells,via direct binding with the coiled-coil(CC)domain of Pib.Interestingly,overexpression of SH3P2 in YY compromised Pib-mediated resistance to M.oryzae isolates carrying AvrPib and Pib-AvrPib recognition-induced cell death.SH3P2 competitively inhibits the self-association of the Pib CC domain in vitro,suggesting that binding of SH3P2 with Pib undermines its homodimerization.Moreover,SH3P2 can also interact with AvrPib and displays higher affinity to AvrPib than to Pib,which leads to dissociation of SH3P2 from Pib in the presence of AvrPib.Taken together,our results suggest that SH3P2 functions as a“protector”to keep Pib in a static state by direct interaction during normal growth but could be triggered off by the invasion of AvrPib-carrying M.oryzae isolates.Our study reveals a new mechanism about how an NLR protein is inactivated under normal conditions but is activated upon pathogen infection.展开更多
文摘水稻黄绿叶突变会显著影响水稻产量和稻米品质.研究黄绿叶突变体叶绿素变化机理对选育高光效品种,促进水稻增产具有重要意义.本研究以甲基磺酸乙酯(ethylmethylsulfone,EMS)诱变处理粳稻云引(YY)后发现的一个黄绿叶突变体w08(YGL)为材料,研究叶色突变对主要农艺性状、叶绿素含量、光合参数变化、水稻生理及亚显微结构的影响,并对该突变性状进行遗传分析、基因定位和功能验证.研究表明,突变体全生育期均表现为黄绿色.与野生型云引(YY)相比,突变体w08单株有效穗、结实率、千粒重分别降低46.7%、50.1%和18.3%,叶绿素a、叶绿素b和类胡萝卜素含量分别下降41.2%、98.7%、17.5%.光合速率检测结果表明,突变体净光合速率(Pn)显著降低,而细胞间CO_(2)(Ci)显著增加.对叶片叶绿体进行超微结构电子显微镜观察,结果发现,叶绿体内的类囊体基粒片层数目在突变体中明显减少.遗传分析结果表明,突变体黄绿叶性状为单基因遗传,受一对隐性核基因控制.利用突变体与雷蒙特(Lemont)杂交构建F2遗传群体,将该基因定位在10号染色体长臂GL8和T258两个标记之间,物理距离为60.2 kb,该区间包含14个候选基因.基因测序发现,该区间内的编码叶绿素酸酯氧化酶1(chlorophyllide a oxygenase1)蛋白的候选基因OsCAO1编码区CDS序列第957位碱基发生突变,形成一个终止密码子,使蛋白翻译提前终止.通过构建过表达和敲除载体进行转基因功能验证,进一步证实了OsCAO1基因功能.分析突变体中的激素含量和分蘖调控相关基因的表达,结果表明,突变体中水稻分蘖相关基因表达水平明显下降,生长素合成基因表达水平显著提高,水稻分蘖芽的生长素含量显著提高,从而证实OsCAO1基因突变抑制了水稻分蘖生长,使单株有效穗显著减少.
文摘在广谱抗稻瘟病品种云引与普感稻瘟病品种丽江新团黑谷(Lijiangxintuanheigu,LTH)构建的近等基因系抗、感病子代基因组重测序的差异基因中,从与免疫应答(immune response)相关的分类单元里得到8个基因序列有差异的基因.它们都为编码富含亮氨酸重复序列的类受体蛋白激酶基因,并聚集于11号染色体的邻近位置,且与已知的白叶枯病抗性基因Xa21具有一定同源性.为进一步探究这些类受体蛋白激酶类基因在稻瘟病抗性中可能发挥的功能,我们分析了这些基因的结构、进化及抗感子代间的序列差异类型,同时还分别采用离体和喷雾接菌的方式对云引和LTH进行稻瘟病接种并取样.通过实时荧光定量PCR(quantitative real time polymerase chain reaction,q RT-PCR)发现,部分基因能受到稻瘟病菌的诱导,推测它们可能在水稻对抗稻瘟病病菌中发挥一定作用,为进一步挖掘稻瘟病相关抗性基因奠定基础.
基金This work was supported by the National Key R&D Program Foundation of China(grant no.2016YFD0300508)the National Rice Industry Technology System of Modern Agriculture for China(grant no.CARS-01-20)+2 种基金the“5511”Collaborative Innovation Project for High-Quality Development and Surpasses of Agriculture between Government of Fujian and Chinese Academy of Agricultural Sciences(grant no.XTCXGC2021001)Key Program of Science and Technology in Fujian province,China(no.2020NZ08016)the Special Foundation of Non-Profit Research Institutes of Fujian Province(grant no.2018R1021-5).
文摘Plants usually keep resistance(R)proteins in a static state under normal conditions to avoid autoimmunity and save energy for growth,but R proteins can be rapidly activated upon perceiving pathogen invasion.Pib,the first cloned blast disease R gene in rice,encoding a nucleotide-binding leucine-rich repeat(NLR)protein,mediates resistance to the blast fungal(Magnaporthe oryzae)isolates carrying the avirulence gene AvrPib.However,the molecular mechanisms about how Pib recognizes AvrPib and how it is inactivated and activated remain largely unclear.In this study,through map-based cloning and CRISPR-Cas9 gene editing,we proved that Pib contributes to the blast disease resistance of rice cultivar Yunyin(YY).Furthermore,an SH3 domain-containing protein,SH3P2,was found to associate with Pib mainly at clathrin-coated vesicles in rice cells,via direct binding with the coiled-coil(CC)domain of Pib.Interestingly,overexpression of SH3P2 in YY compromised Pib-mediated resistance to M.oryzae isolates carrying AvrPib and Pib-AvrPib recognition-induced cell death.SH3P2 competitively inhibits the self-association of the Pib CC domain in vitro,suggesting that binding of SH3P2 with Pib undermines its homodimerization.Moreover,SH3P2 can also interact with AvrPib and displays higher affinity to AvrPib than to Pib,which leads to dissociation of SH3P2 from Pib in the presence of AvrPib.Taken together,our results suggest that SH3P2 functions as a“protector”to keep Pib in a static state by direct interaction during normal growth but could be triggered off by the invasion of AvrPib-carrying M.oryzae isolates.Our study reveals a new mechanism about how an NLR protein is inactivated under normal conditions but is activated upon pathogen infection.
