水稻ES1参与生物钟基因表达调控以及逆境胁迫响应

生物钟参与调控植物所有的生长阶段和发育活动。维持植物生物钟稳定的基因在这一过程中起着决定性作用。在克隆了ES1 (EARLY SENESCENCE 1)基因并证明该基因影响水稻(Oryza sativa)叶片失水的基础上, 以前期分离得到的水稻突变体es1-1作为研究对象, 对es1-1及其野生型(日本晴)苗期的地上部分和地下部分进行基因芯片分析。结果表明, es1-1主要的上调基因有42个, 下调基因有14个, 这些差异基因涉及24种代谢途径, 包括调节水稻生物钟的途径(4个)、甲烷代谢途径(3个)和苯基丙氨酸代谢途径(3个)等。进一步对水稻生物钟相关基因进行表达图谱分析, 结果表明, 与野生型相比, es1-1中生物钟相关基因出现了不同程度的差异表达。对es1-1和野生型进行冷胁迫处理, 结果表明es1-1表现更加耐冷, 且冷处理后生物钟基因在日本晴(NPB)和es1-1中都表现出不同程度的差异表达。此外, 在分蘖盛期接种白叶枯菌, 发现es1-1对特定的白叶枯菌具有一定的抗性。由此推测ES1基因参与调控水稻生物钟基因的表达以及响应水稻部分逆境胁迫, 这为更深入研究水稻生物钟基因提供了新线索。

EARLY SENESCENCE 1 Participates in the Expression Regulation of Circadian Clock Genes and Response to Stress in Rice

Plant circadian clock genes help control the activities of all growth stages and development. We cloned EARLY SENESCENCE 1 (ES1), which affects water loss in rice, and used a segregation mutant es1-1 and the wild type (NPB) for microarray assay of the root and leaf tissue. The mutant es1-1 had 42 major upregulated genes and 14 major downregulated genes involved in 24 metabolic pathways, including regulating the circadian clock (n=4), methane metabolism (n=3), and phenylalanine metabolism (n=3). On expression profiling of rice circadian clock-related genes, the expression in es1-1 differed from that in the wild type. After cold treatment, es1-1 exhibited more cold tolerance than the wild type, and expression analysis of the circadian clock-related genes revealed changes in es1-1 and NPB. Moreover, after inoculating Xanthomonas oryzae pv. oryzae, es1-1 showed enhanced resistance during tillering as compared with the wild type. ES1 may participate in the expression regulation of rice circadian clock genes, as well as response to some certain stress, which provide further clues for research of rice circadian clock genes.