玉米根部萜类合酶基因对干旱与激素处理的表达差异分析

Expression Analysis of Terpene Synthases in Roots of Maize Inbred Lines in Response to Drought and Phytohormone Treatments

选用两个具有抗性差异的玉米自交系B73与Mo17,分别对其根部进行干旱、脱落酸(ABA)、茉莉酸甲酯(MeJA)以及茉莉酸甲酯与乙烯利联合(MeJA/EP)处理,定量检测4个与防御相关的萜类合酶基因An2、ZmTPS6、ZmTPS8以及ZmTPS26的表达情况。结果表明,4个基因在B73与Mo17应对干旱和ABA处理时基因表达差异明显。在Mo17中,干旱胁迫以及ABA处理显著诱导4个基因的表达;在B73中,干旱处理导致An2、ZmTPS6和ZmTPS8基因表达下调,在ABA处理下时,只有ZmTPS6被显著上调;MeJA与MeJA/EP处理在B73与Mo17中都能上调4个基因的表达,但在Mo17中的诱导程度更剧烈。B73与Mo17的根部在响应胁迫时存在显著的萜类代谢差异,可能为其抗性差异原因之一。

Two different disease-resistant inbred lines of maize B73 and Mo17 were used to treat their roots with drought, abscisic acid（ABA）, jasmonic acid（MeJA）, JA plus ethephon（MeJA＋EP） respectively. Through the real-time PCR analysis, the expression patterns of four terpene synthase genes, An2, ZmTPS6, ZmTPS8 and ZmTPS26 were explored in response to these treatments. They exhibited different even contrast gene expression patterns in these two inbred lines in response to drought and ABA treatment. In Mo17, all four genes can be induced by drought and ABA treatments, however, in B73, An2, ZmTPS6 and ZmTPS8 were suppressed by drought and only ZmTPS6 was induced by ABA treatment. All these four genes accumulated in both B73 and Mo17 under MeJA and MeJA/EP treatments, but the induction level is much higher in Mo17. These results indicated that B73 and Mo17 had different terpenoid metabolism in their roots in response to stress, which might contribute to their resistance difference. This investigation might shed light on resistance breeding and chemical defense in maize roots.