ZmbZIP91 regulates expression of starch synthesis-related genes by binding to ACTCAT elements in their promoters
ZmbZIP91 regulates expression of starch synthesis-related genes by binding to ACTCAT elements in their promoters
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DOI：
10.1093/jxb/erv527
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发表时间：
2016-03-01
影响因子：
6.9
通讯作者：
Huang, Yubi
中科院分区：
文献类型：
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作者：
Chen, Jiang;Yi, Qiang;Huang, Yubi
淀粉合成是影响作物产量和品质的关键过程，但人们对这一复杂代谢途径的调控知之甚少。在这里，我们通过共表达分析确定ZmbZIP91是玉米(Zea Mays L.)淀粉合成的候选调控基因。ZmbZIP91与淀粉合成基因的表达密切相关。逆转录-聚合酶链式反应(RT-PCR)和RNA原位杂交结果表明，ZmbZIP91在玉米胚乳中高表达，在叶片中表达较少。基因枪法在玉米胚乳和叶片原生质体中的瞬时表达表明，ZmbZIP91可以正向调控叶片和胚乳中淀粉合成基因的表达。此外，拟南芥突变体vip1携带了一个与ZmbZIP91同源的基因(VIP1)突变，表现出生长异常，叶片中淀粉较少，而ZmbZIP91能够补充这一表型，导致正常的淀粉合成。酵母单杂交实验和EMSA分析表明，ZmbZIP91可以直接与淀粉合成基因启动子(pAGPS1、pSSI、pSSIIIa和pISA1)中的ACTCAT元件结合。这些结果表明，ZmbZIP91通过与淀粉合成基因启动子中的ACTCAT元件结合而成为淀粉合成的核心调控因子。
Starch synthesis is a key process that influences crop yield and quality, though little is known about the regulation of this complex metabolic pathway. Here, we present the identification of ZmbZIP91 as a candidate regulator of starch synthesis via co-expression analysis in maize (Zea mays L.). ZmbZIP91 was strongly associated with the expression of starch synthesis genes. Reverse tanscription-PCR(RT-PCR) and RNA in situ hybridization indicated that ZmbZIP91 is highly expressed in maize endosperm, with less expression in leaves. Particle bombardment- mediated transient expression in maize endosperm and leaf protoplasts demonstrated that ZmbZIP91 could positively regulate the expression of starch synthesis genes in both leaves and endosperm. Additionally, the Arabidopsis mutant vip1 carried a mutation in a gene (VIP1) that is homologous to ZmbZIP91, displayed altered growth with less starch in leaves, and ZmbZIP91 was able to complement this phenotype, resulting in normal starch synthesis. A yeast one-hybrid experiment and EMSAs showed that ZmbZIP91 could directly bind to ACTCAT elements in the promoters of starch synthesis genes (pAGPS1, pSSI, pSSIIIa, and pISA1). These results demonstrate that ZmbZIP91 acts as a core regulatory factor in starch synthesis by binding to ACTCAT elements in the promoters of starch synthesis genes.