Combinatorial interaction of two adjacent cis-active promoter regions mediates the synergistic induction of Bt2 gene by sucrose and ABA in maize endosperm
Combinatorial interaction of two adjacent cis-active promoter regions mediates the synergistic induction of Bt2 gene by sucrose and ABA in maize endosperm
复制标题
玉米胚乳中两个相邻顺式活性启动子区的组合相互作用介导蔗糖和ABA协同诱导Bt2基因
DOI：
10.1016/j.plantsci.2018.06.003
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发表时间：
2018-09-01
期刊：
影响因子：
5.2
通讯作者：
Huang, Yubi
中科院分区：
文献类型：
--
作者：
Li, Yangping;Yu, Guowu;Huang, Yubi
淀粉在胚乳中的积累是决定作物产量和品质的关键过程。研究表明，蔗糖和脱落酸（阿坝）协同调节作物淀粉的合成。然而，人们对这种协同效应背后的分子机制知之甚少。本文研究了蔗糖和阿坝对玉米胚乳淀粉合成的影响。蔗糖或阿坝单独处理可使淀粉含量、ADP-Glc焦磷酸化酶（AGP-Glc pyrophosphorylase，AGP-Glc pyrophosphorylase）浓度和AGPase编码基因的表达量略有增加，但蔗糖和阿坝共同处理则显著增加。通过在玉米胚乳中瞬时表达对Bt 2启动子的截短分析表明，启动子区域（-370/-186）参与蔗糖响应，并且邻近区域（-186/-43）响应阿坝。蔗糖和阿坝对Bt 2启动子活性的协同诱导需要与这两个区域的相互作用。有趣的是，去除蔗糖响应区（-370至-186）消除了Bt 2启动子中的阿坝响应性，即使在ABA响应区（-186至-43）存在的情况下。本研究为蔗糖和阿坝协同调控谷物胚乳淀粉合成和籽粒灌浆的调控机制提供了新的见解。
The accumulation of starch in cereal endosperm is a key process that determines crop yield and quality. Research has reported that sucrose and abscisic acid (ABA) synergistically regulate the synthesis of crop starch. However, little is known about the molecular mechanisms behind this synergistic effect. In this study, the effect of sucrose and ABA on starch synthesis in maize endosperm was investigated. The starch content, the ADP-Glc pyrophosphorylase (AGPase) concentration, and the expression of AGPase-encoding genes were found to be enhanced slightly by sucrose or ABA alone, but were elevated significantly by the co-treatment of sucrose and ABA. Truncation analysis of the Bt2 promoter via transient expression in maize endosperm showed that the promoter region (-370/-186) is involved in sucrose response, and that an adjacent region (-186/-43) responds to ABA. The synergistic induction of sucrose and ABA on Bt2 promoter activity requires interaction with both of these regions. Interestingly, removal of the sucrose-responsive region (-370 to -186) abolishes ABA responsiveness in the Bt2 promoter, even in the presence of ABA-responsive region (-186 to -43). This study provides novel insights into the regulatory mechanisms that underlie the synergistic regulation of starch synthesis and grain filling from sucrose and ABA in cereal endosperm.