Gibberellin regulates post-microsporogenesis processes in petunia anthers
Gibberellin regulates post-microsporogenesis processes in petunia anthers
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DOI：
10.1034/j.1399-3054.2002.1150314.x
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发表时间：
2002-07-01
影响因子：
6.4
通讯作者：
Weiss, D
中科院分区：
文献类型：
--
作者：
Izhaki, A;Borochov, A;Weiss, D
以往的研究表明，赤霉素（GAs）是在矮牵牛花药中产生的，并运输到花冠，以诱导生长和色素沉着。本工作研究了GA在花药发育调控中的作用。当矮牵牛植株用GA生物合成抑制剂多效唑处理时，花药发育被阻止。这些花药的显微镜分析表明，多效唑抑制减数分裂后的发育过程。处理后的花药含有花粉粒，但药隔组织和绒毡层细胞退化。当拟南芥GA信号抑制子SPY在转基因矮牵牛植物中过表达时，获得了类似的表型，即花药发育在小孢子发生后被阻止。GA诱导基因GIP的表达可以作为研究矮牵牛GA反应的分子标记。GA（3）处理幼花药促进GIP表达，而多效唑抑制GIP表达，表明激素控制着花药中基因的自然激活。对GIP在花药发育过程中表达的分析表明，该基因仅在小孢子发生后被诱导。这一观察结果进一步表明GA在调控矮牵牛花药发育过程中的减数分裂后过程中的作用。
Previous studies have suggested that gibberellins (GAs) are produced in petunia anthers and transported to the corolla to induce growth and pigmentation. In this work, we studied the role of GA in the regulation of anther development. When petunia plants were treated with the GA-biosynthesis inhibitor paclobutrazol, anther development was arrested. Microscopic analysis of these anthers revealed that paclobutrazol inhibits post-meiotic developmental processes. The treated anthers contained pollen grains but the connective tissue and tapetum cells were degenerated. A similar phenotype was obtained when the Arabidopsis GA-signal repressor, SPY, was over-expressed in transgenic petunia plants, i.e. anther development was arrested following microsporogenesis. The expression of the GA-induced gene, GIP , can be used in petunia as a molecular marker to study GA responses. GA(3) treatment of young anthers promoted, and paclobutrazol inhibited, GIP expression, suggesting that the hormone controls the natural activation of the gene in the anthers. Analyses of GIP expression during anther development revealed that the gene is induced only after microsporogenesis. This observation further suggests a role for GA in the regulation of post-meiotic processes during petunia anther development.