基于RNA-Seq技术分析植物激素信号途径在水稻幼苗中对低温胁迫的应答规律

Genome-wide expression analysis of the phytohormones signalling pathway in rice seedlings by using RNA-Seq

水稻对低温敏感,幼苗时期的低温胁迫会影响水稻的生长,甚至致死,从而导致减产。植物激素在植物低温胁迫响应过程中发挥着重要作用。在本研究中,我们以籼稻品种特青和粳稻品种02428为试验材料,在不同低温处理时间下(10℃处理0、3或24 h),运用RNA-Seq技术开展水稻苗期低温应答转录组分析。结果表明:粳稻02428的耐低温性显著强于籼稻特青,低温处理后,在两个品种中均检测到大量差异表达基因。在差异表达基因的KEGG通路分析中,植物激素信号通路是低温胁迫下差异表达基因最显著富集的通路,说明植物激素通路在水稻苗期耐低温中具有重要作用。我们通过对生长素、细胞分裂素等8种激素信号途径中差异表达基因的数量及其表达量进行分析,解析了各激素信号通路中的关键基因在低温胁迫下表达量的变化趋势,最终发现在水稻苗期耐低温中可能起正调控作用的激素是乙烯、脱落酸和茉莉酸,负调控耐低温的是细胞分裂素和赤霉素。本研究为深入了解植物激素参与水稻苗期耐低温调控的机制提供了方向与依据。

Rice is highly sensitive to cold stress, low temperature during seedling stage will affect the growth of rice, sometimes even cause death and result in yield loss. In this study, indica rice cultivar Teqing and japonica rice cultivar 02428 were treated under low temperature (10 ℃ for 0, 3 and 24 h) to conduct trancriptome analysis by using RNA-Seq. Our result showed japonica rice 02428 had stronger cold resistance than indica rice Teqing. After cold treatment, we identified many differentially expressed genes in both cultivars. In KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis,“plant hormone signal transduction” pathway was the most significant enriched pathway, which suggested that plant hormones could play important roles in regulating cold tolerance in rice. By analyzing the number and expression level of plant hormone related DEGs, we understanded the expression trend of key genes among the plant hormone signalling pathways. We found ethylene, abscisic acid and jasmonic acid may worked as positive regulators in cold resistance in rice seedlings, while cytokinin and gibberenllin played negative roles. Our result provides direction and basis for further study of cold response mechanism of plant hormones in rice seedlings.