小麦低磷响应基因的筛选与表达分析

利用Affymetrix wheat microarray分析了郑麦9023在低磷和正常磷水培条件下,苗期根部基因在转录水平的差异。结果表明,1)筛选得到1 889个差异表达基因,其中1 298个上调表达,591个下调表达。2)基因功能分析显示,这1 889个基因参与了信号转导、蛋白存储、逆境胁迫、能量代谢、病程相关和其他与植物生长发育有关的过程。3)利用qRT-PCR对其中30个基因的表达情况进行了验证,显示与基因芯片结果基本相同的表达趋势。4)在低磷及磷恢复条件下,对其中5个候选基因(TaSPX3,TaIPS1.3,TaGST_Like,TaPDF19,TaG6PDH1_Like)在不同小麦品种中的表达进行分析,显示这5个基因受到低磷胁迫的强烈诱导,恢复供磷后表达显著回调。但是,这些候选基因在不同品种间横向表达趋势有差别,反应了不同基因型小麦对低磷胁迫的响应机制存在差异。预测这5个候选基因的功能涉及信号转导、氨基酸代谢、糖代谢、抗逆响应等重要的代谢或调控途径,在小麦应对低磷逆境机制中发挥重要作用。

Screening and expression analysis of genes responded to low phosphate in wheat root

The expression diffecences of genes responded to low phosphate (-P) and full phosphate (+P) in wheat roots were analyzed by Affymetrix wheat microarray.A total of 1 889 genes were differentially expressed,of which 1 298 and 591 genes were found to be either up-regulated or down-regulated.The functional classification of those differentially expressed genes showed that they were involved in signal transduction,protein storage,stress response,energy metabolism,and pathogenesis and other processes related to plant growth and development.In addition,the expression patterns of 30 differentially expressed genes were verified by qRT-PCR and exhibited a generally same results with microarray data.Five candidate genes (TaSPX3,TaIPS1.3,TaGST_Like,TaPDF19 and TaG6PDH1_Like) were obtained and used to assay their expression patterns in different wheat cultivars under low and phosphate re-supply treatments.The 5 selected candidate genes were strongly up-regulated by low phosphate treatment and returned to normal level gradually after phosphate re-supply;However,the different expression patterns among different wheat cultivars indicated that they might differ in the mechanisms to cope with low phosphate stress.The putative functions of the 5 selected genes were involved in several important metabolic or regulatory pathways,such as signal transduction,amino acid metabolism,glucose metabolism,stress response.They might play an important role in response to low phosphate stress and can be useful for genetic improvement in phosphate high efficiency of wheat.