碱胁迫应答GsGASA1及GsGASA2基因表达特性研究

Expression analysis of two alkali stress related genes GsGASA1 and GsGASA2

野生大豆具有很强的抗逆性和适应能力,是利用基因工程手段进行作物抗逆分子育种的重要基因来源供体材料。为了获得具有自主知识产权、在植物渗透胁反应中起关键作用的功能基因,利用前期构建的野生大豆碱胁迫基因芯片表达谱,从中选取两个碱胁迫处理下显著上调表达,经分析预测属于GASA基因家族的基因(probesets分别为Gma.15958.1.S1_at;GmaAffx.90343.1.S1_at),分别命名为GsGASA1、GsGASA2。对上述两个基因进行了芯片结果的sqRT-PCR验证,并分析了其在野生大豆中经盐、干旱、冷胁迫处理下的表达特性。结果表明,GsGASA1、GsGASA2基因对这三种胁迫处理均表现出应答反应,虽然在不同胁迫条件下表达高峰出现的时间和表达强度上存在差异,但均呈现出在短期内显著上调表达的表达模式,推测GsGASA1、GsGASA2基因在非生物胁迫中将起到一定作用。另外,GsGASA1、GsGASA2基因的表达受GA诱导及PAC、ABA的抑制。研究将为下一步GsGASA1、GsGASA2全长基因的克隆及其在非生物胁迫中的功能研究奠定基础,也为研究GA和ABA信号通路的相互作用提供线索。

Wild soybean （Glycine soja） has characteristic of better stress-resistance and adaptive capacity. It is an important gene resource in molecular breeding by means of transgenic technology. In order to gain some new key function genes in the plant responsive to osmotic stress, It had analyzed the transcriptome changes in Glycine soja roots under NaHCO3 treatments using Affymetrix Soybean Genome Array. In this. study, two up-regulated genes under alkaline stress were selected from the transcriptome profiling analysis result. Their probe sets are Gma. 15958.1 .S1_at and GmaAffx.90343.1. S1_at, respectively. They were speculated as members of GASA family with the bioinformatical analysis, thus named as GsGASA1 and GsGASA2, respectively. Microarray expression level of GsGASA1 and GsGASA2 genes were validated by semiquantitative PCR （sqRT-PCR）. And it also investigated the expression pattern of GsGASA1 and GsGASA2 genes at transcription level responding to other abiotic stresses such as salt, drought and cold treatments, which revealed that GsGASAland GsGASA2 genes were distinctly responsive to these abiotic stresses. Although the expression peak time and intensity were different, the two genes were up-regulated in the short term, suggesting that GsGASA1 and GsGASA2 genes may play a role in abiotic stresses. In addition, the expression level of GsGASA1 and GsGASA2 genes were induced by GA and inhibited by ABA. These results have provided an important basis for the cloning and functional analysis of GsGASA1 and GsGASA2 genes in abiotic stresses. The research provided some clues to elucidate the function of GASA proteins in the GA and ABA signal transduction pathway.