水稻光敏色素A和B的突变对气孔发育和OsAQP基因表达的影响

Effects of Rice Phytochrome A and B Mutations on Stomatal Development and Expression of OsAQP Gene

OsAQP是在水稻叶片保卫细胞中高表达的液泡膜型水通道基因,为研究该基因在水稻发育过程中的表达与光敏色素光信号通路的关系,观察统计了日本晴、光敏色素突变体phyA和phyB 3个水稻品种的生长发育特征,比较了开花时间、叶片气孔密度、气孔器长等指标,并采用半定量RT-PCR以及实时定量PCR技术检测OsAQP基因在3种材料不同时期叶片中的表达特性。结果显示,光敏色素突变体phyB叶片的气孔密度、气孔器长度均低于同时期的日本晴和光敏色素突变体phyA水稻,说明光敏色素B及其相关信号可能与气孔的发育关系密切;表达模式分析显示,OsAQP基因在3个水稻品种的叶片中具有不同的表达特性,并伴随发育时期呈现下降的趋势。本研究结果说明水稻光敏色素B以及相关信号不仅与气孔的发育有关,而且可能通过与光敏色素A及相关信号通路共同调节OsAQP基因的表达,参与气孔开闭的调节。

OsAQP is a rice vacuolar membrane-type aquaporin gene highly expressed in leaves guard cells. In order to study its expression profile during rice development and the relationship with phytoehrome-mediated light signal pathway, we focused on the flowering time, stomatal density and length of wild type, phytochrome A and B mutants rice in this report, and the expression pattern of OsAQP in the leaves of three varieties were detected by semi-quantitative RT-PCR and real time PCR. The result indicates that the stomatal density and length in phytochrome B mutant were lowest compared with the other varieties at the same stage, indicating that phytochrome B-mediated pathway is involved in the stoma development, qRT-PCR result demonstrated that the expression level of OsAQP in the three varieties are different, but invariably showed downward trend during the development. Taken together, these results implicate rice phytochrome B-mediated light signal pathway in stomatal development, and phytochrome B pathway may participate in the opening and closing regulation of stoma accompanied by the phytochrome A signaling through the expression regulation of OsAQP.