Chemical genetic dissection of brassinosteroid-ethylene interaction
Chemical genetic dissection of brassinosteroid-ethylene interaction
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DOI：
10.1093/mp/ssn005
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发表时间：
2008-03-01
期刊：
影响因子：
27.5
通讯作者：
Wang, Zhi-Yong
中科院分区：
文献类型：
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作者：
Gendron, Joshua M.;Haque, Asif;Wang, Zhi-Yong
我们进行了化学遗传学筛选，以确定油菜素类固醇（BR）作用的化学抑制剂。从10，000个小分子的化学文库中，发现一种化合物抑制拟南芥下胚轴长度并激活BR抑制的报告基因（CPD：：GUS）的表达，并将其命名为油菜素必利（BRP）。BRP的这些作用可以通过与油菜素钠共处理来逆转，表明BRP直接或间接地抑制BR的生物合成。有趣的是，该化合物导致夸张的顶端钩，类似于乙烯处理引起的。BRP诱导的顶钩表型可以被乙烯感知的化学抑制剂或乙烯不敏感突变体阻断，这表明除了抑制BR外，BRP还激活乙烯反应。BRP类似物的分析提供了有关其对BR和乙烯途径中两个单独靶标的作用的重要结构特征的线索。各种BR和乙烯突变体BRP，乙烯和BR处理的反应分析揭示了乙烯和BR在黑暗生长的幼苗之间的串扰模式。我们的研究结果表明，积极的下游BR信号，而不是BR合成或BR梯度，是必要的乙烯诱导的顶端钩形成。与BRP相关的化合物可以成为操纵植物生长和研究激素相互作用的有用工具。
We undertook a chemical genetics screen to identify chemical inhibitors of brassinosteroid (BR) action. From a chemical library of 10,000 small molecules, one compound was found to inhibit hypocotyl length and activate the expression of a BR-repressed reporter gene (CPD::GUS) in Arabidopsis, and it was named brassinopride (BRP). These effects of BRP could be reversed by co-treatment with brassinolide, suggesting that BRP either directly or indirectly inhibits BR biosynthesis. Interestingly, the compound causes exaggerated apical hooks, similar to that caused by ethylene treatment. The BRP-induced apical hook phenotype can be blocked by a chemical inhibitor of ethylene perception or an ethylene-insensitive mutant, suggesting that, in addition to inhibiting BR, BRP activates ethylene response. Analysis of BRP analogs provided clues about structural features important for its effects on two separate targets in the BR and ethylene pathways. Analyses of the responses of various BR and ethylene mutants to BRP, ethylene, and BR treatments revealed modes of cross-talk between ethylene and BR in dark-grown seedlings. Our results suggest that active downstream BR signaling, but not BR synthesis or a BR gradient, is required for ethylene-induced apical hook formation. The BRP-related compounds can be useful tools for manipulating plant growth and studying hormone interactions.