Binding of ABI4 to a CACCG motif mediates the ABA-induced expression of the ZmSSI gene in maize (Zea mays L.) endosperm
Binding of ABI4 to a CACCG motif mediates the ABA-induced expression of the ZmSSI gene in maize (Zea mays L.) endosperm
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ABI4 与 CACCG 基序的结合介导 ABA 诱导的玉米 (Zea mays L.) 胚乳中 ZmSSI 基因的表达
DOI：
10.1093/jxb/ers246
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发表时间：
2012-10-01
影响因子：
6.9
通讯作者：
Huang, Yubi
中科院分区：
文献类型：
--
作者：
Hu, Yu-Feng;Li, Yang-Ping;Huang, Yubi
淀粉合成酶I（SSI）在玉米胚乳发育中贡献了大部分淀粉合成酶活性。在这项工作中，各种植物激素和糖对淀粉合成酶I基因（ZmSSI）在发育中的玉米胚乳的表达的影响进行了研究。使用脱落酸（阿坝），但不与葡萄糖，蔗糖，或赤霉素处理诱导ZmSSI mRNA的积累。为了研究这种效应的分子机制，分离并分析了ZmSSI启动子区域（1537至51）。玉米胚乳组织中的瞬时表达试验表明，全长ZmSSI启动子可被阿坝激活。缺失和突变分析的结果表明，ZmSSI启动子中的CACCG基序负责阿坝诱导。结合位移分析的结果表明，该CACCG基序与玉米ABI4蛋白在体外相互作用。胚乳组织中ABI4的过表达增强了在阿坝处理的情况下含有CACCG基序的启动子的活性。表达模式分析表明，阿坝处理诱导发育中的玉米胚乳ABI4的转录模式，但只有轻微的葡萄糖或蔗糖处理的影响。综上所述，这些数据表明ABI4与ZmSSI启动子中的CACCG基序结合并介导其阿坝诱导。
Starch synthase I (SSI) contributes the majority of the starch synthase activity in developing maize endosperm. In this work, the effects of various plant hormones and sugars on the expression of the starch synthase I gene (ZmSSI) in developing maize endosperms were examined. The accumulation of ZmSSI mRNA was induced using abscisic acid (ABA) but not with glucose, sucrose, or gibberellin treatment. To investigate the molecular mechanism underlying this effect, the ZmSSI promoter region (1537 to 51) was isolated and analysed. A transient expression assay in maize endosperm tissue showed that the full-length ZmSSI promoter is activated by ABA. The results of deletion and mutation assays demonstrated that a CACCG motif in the ZmSSI promoter is responsible for the ABA inducibility. The results of binding shift assays indicated that this CACCG motif interacts with the maize ABI4 protein in vitro. The overexpression of ABI4 in endosperm tissue enhanced the activity of a promoter containing the CACCG motif in the absence of ABA treatment. Expression pattern analysis indicated that the transcription pattern of ABI4 in the developing maize endosperm was induced by ABA treatment but was only slightly affected by glucose or sucrose treatment. Taken together, these data indicate that ABI4 binds to the CACCG motif in the ZmSSI promoter and mediates its ABA inducibility.