叶片早衰直接影响作物的产量与品质,因此,研究叶片早衰的分子与生理机制对于作物遗传改良具有重要的意义。本研究利用60Co-γ辐射诱变水稻品种93-11获得突变体osled,其从分蘖期叶片就开始早衰,最先表现为叶尖和叶边缘变褐,并伴有红褐色...叶片早衰直接影响作物的产量与品质,因此,研究叶片早衰的分子与生理机制对于作物遗传改良具有重要的意义。本研究利用60Co-γ辐射诱变水稻品种93-11获得突变体osled,其从分蘖期叶片就开始早衰,最先表现为叶尖和叶边缘变褐,并伴有红褐色斑点。在苗期经模拟干旱胁迫处理后,突变体不仅早衰,而且植株变矮以及根系变短。生理分析表明,野生型剑叶、倒二叶和倒三叶的丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性及过氧化物酶(POD)活性基本不变,但突变体则显著升高且倒二叶和倒三叶极显著高于野生型;突变体和野生型三片叶的可溶性蛋白含量、过氧化氢酶(CAT)活性及叶绿素总含量均表现下降,但突变体倒二叶和倒三叶的含量或活性均显著低于野生型。叶片经台盼蓝、二氨基联苯胺(DAB)及四唑硝基蓝(NBT)等细胞组织化学染色及透射电镜分析表明,osled叶片细胞膜系统已破坏,H2O2和O2-积累,叶绿体已开始解体。遗传分析表明,osled受1对隐性基因控制,借助图位克隆技术将该基因定位于第3染色体长臂的RM15528与RM15553两个标记之间,遗传距离均为0.7 c M,该结果为进一步克隆Os LED基因并研究其功能奠定了基础。展开更多
本研究报道了一个来自EMS诱变优良恢复系浙恢7954的新水稻早衰突变体lst(Leaf senescence at tillering stage),其最主要的表型特点是叶片上出现锈色衰老斑,通过荧光共聚焦倒置显微镜观察和透射电子显微镜镜观察表明lst的叶绿素荧光减弱...本研究报道了一个来自EMS诱变优良恢复系浙恢7954的新水稻早衰突变体lst(Leaf senescence at tillering stage),其最主要的表型特点是叶片上出现锈色衰老斑,通过荧光共聚焦倒置显微镜观察和透射电子显微镜镜观察表明lst的叶绿素荧光减弱,叶绿体结构异常。生理生化分析发现lst突变体剑叶在早衰性状出现时,与野生型相比,其叶绿素和类胡萝卜素含量显著降低;O2-、H2O2、MDA含量升高,保护酶系统SOD和CAT活性降低。遗传分析表明,该突变体受1对隐性核基因控制,利用200株日本晴/lst的F2隐性定位群体,最终将LST基因定位在第3染色体SSR标记RM3646和InDel标记IAC120537-1,2之间,共171kb,含两个BAC,30个基因,这为基因的克隆和功能研究奠定了基础。展开更多
Leaf rolling and discoloration are two chilling-injury symptoms that are widely used as indicators for the evaluation of cold tolerance at the seedling stage in rice. However, the difference in cold-response mechanism...Leaf rolling and discoloration are two chilling-injury symptoms that are widely used as indicators for the evaluation of cold tolerance at the seedling stage in rice. However, the difference in cold-response mechanisms underlying these two traits remains unknown. In the present study, a cold-tolerant rice cultivar, Lijiangxintuanheigu, and a cold-sensitive cultivar, Sanhuangzhan-2, were subjected to low-temperature treatments and physiolog-ical and genome-wide gene expression analyses were conducted. Leaf rolling occurred at temperatures lower than 11℃, whereas discoloration appeared at moderately low temperatures such as 13℃. Chlorophyll contents in both cultivars were significantly decreased at 13℃, but not altered at 11℃. In contrast, the relative water content and relative electrolyte leakage of both cultivars decreased significantly at 11℃, but did not change at 13℃. Expression of genes associated with calcium signaling and abscisic acid (ABA) degradation was significantly altered at 11℃ in comparison with 25℃ and 13℃. Numerous genes in the DREB, MYB, bZIP, NAC, Zinc finger, bHLH, and WRKY gene families were differentially expressed. Many aquaporin genes and the key genes in trehalose and starch synthesis were down regulated at 11℃ in comparison with 25℃ and 13℃. These results suggest that the two chilling injury symptoms are temperature-specific and are controlled by different mechanisms. Cold-induced leaf rolling is associated with calcium and ABA signaling pathways and is regulated by multiple transcriptional regulators. The suppression of aquaporin genes and reduced accumulation of soluble sugars under cold stress results in a reduction in cellular water potential and consequently leaf rolling.展开更多
文摘叶片早衰直接影响作物的产量与品质,因此,研究叶片早衰的分子与生理机制对于作物遗传改良具有重要的意义。本研究利用60Co-γ辐射诱变水稻品种93-11获得突变体osled,其从分蘖期叶片就开始早衰,最先表现为叶尖和叶边缘变褐,并伴有红褐色斑点。在苗期经模拟干旱胁迫处理后,突变体不仅早衰,而且植株变矮以及根系变短。生理分析表明,野生型剑叶、倒二叶和倒三叶的丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性及过氧化物酶(POD)活性基本不变,但突变体则显著升高且倒二叶和倒三叶极显著高于野生型;突变体和野生型三片叶的可溶性蛋白含量、过氧化氢酶(CAT)活性及叶绿素总含量均表现下降,但突变体倒二叶和倒三叶的含量或活性均显著低于野生型。叶片经台盼蓝、二氨基联苯胺(DAB)及四唑硝基蓝(NBT)等细胞组织化学染色及透射电镜分析表明,osled叶片细胞膜系统已破坏,H2O2和O2-积累,叶绿体已开始解体。遗传分析表明,osled受1对隐性基因控制,借助图位克隆技术将该基因定位于第3染色体长臂的RM15528与RM15553两个标记之间,遗传距离均为0.7 c M,该结果为进一步克隆Os LED基因并研究其功能奠定了基础。
文摘本研究报道了一个来自EMS诱变优良恢复系浙恢7954的新水稻早衰突变体lst(Leaf senescence at tillering stage),其最主要的表型特点是叶片上出现锈色衰老斑,通过荧光共聚焦倒置显微镜观察和透射电子显微镜镜观察表明lst的叶绿素荧光减弱,叶绿体结构异常。生理生化分析发现lst突变体剑叶在早衰性状出现时,与野生型相比,其叶绿素和类胡萝卜素含量显著降低;O2-、H2O2、MDA含量升高,保护酶系统SOD和CAT活性降低。遗传分析表明,该突变体受1对隐性核基因控制,利用200株日本晴/lst的F2隐性定位群体,最终将LST基因定位在第3染色体SSR标记RM3646和InDel标记IAC120537-1,2之间,共171kb,含两个BAC,30个基因,这为基因的克隆和功能研究奠定了基础。
基金supported in part by the Ph.D. Start-up Fund of Natural Science Foundation of Guangdong Province, China (2015A030310419)the Guangdong Scientific and Technological Plan (2015B020231002, 2017A070702006, 2017A020208022)+3 种基金the Guangzhou Scientific and Technological Plan (201804020078)the Guangdong-Hong Kong joint project (2017A050506035)the Development Project of Guangdong Provincial Key Lab (2017B030314173)the Special Fund of Central Government Guided Local Scientific Development
文摘Leaf rolling and discoloration are two chilling-injury symptoms that are widely used as indicators for the evaluation of cold tolerance at the seedling stage in rice. However, the difference in cold-response mechanisms underlying these two traits remains unknown. In the present study, a cold-tolerant rice cultivar, Lijiangxintuanheigu, and a cold-sensitive cultivar, Sanhuangzhan-2, were subjected to low-temperature treatments and physiolog-ical and genome-wide gene expression analyses were conducted. Leaf rolling occurred at temperatures lower than 11℃, whereas discoloration appeared at moderately low temperatures such as 13℃. Chlorophyll contents in both cultivars were significantly decreased at 13℃, but not altered at 11℃. In contrast, the relative water content and relative electrolyte leakage of both cultivars decreased significantly at 11℃, but did not change at 13℃. Expression of genes associated with calcium signaling and abscisic acid (ABA) degradation was significantly altered at 11℃ in comparison with 25℃ and 13℃. Numerous genes in the DREB, MYB, bZIP, NAC, Zinc finger, bHLH, and WRKY gene families were differentially expressed. Many aquaporin genes and the key genes in trehalose and starch synthesis were down regulated at 11℃ in comparison with 25℃ and 13℃. These results suggest that the two chilling injury symptoms are temperature-specific and are controlled by different mechanisms. Cold-induced leaf rolling is associated with calcium and ABA signaling pathways and is regulated by multiple transcriptional regulators. The suppression of aquaporin genes and reduced accumulation of soluble sugars under cold stress results in a reduction in cellular water potential and consequently leaf rolling.
