Auxin regulates Arabidopsis anther dehiscence, pollen maturation, and filament elongation
Auxin regulates Arabidopsis anther dehiscence, pollen maturation, and filament elongation
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DOI：
10.1105/tpc.107.057570
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发表时间：
2008-07-01
期刊：
影响因子：
11.6
通讯作者：
Cardarelli, Maura
中科院分区：
文献类型：
--
作者：
Cecchetti, Valentina;Altamura, Maria Maddalena;Cardarelli, Maura
我们提供了生长素的定位、合成、运输以及对拟南芥雄蕊发育后期发生的过程的影响的证据：花药开裂、花粉成熟和花前花丝伸长。生长素敏感报告构建体的表达表明，生长素效应开始于减数分裂末期和参与开裂第一步的体细胞组织的双眼阶段之间的花药中，以及小孢子中以及花药和花丝之间的连接区域中。生长素生物合成基因YUC2和YUC6的原位杂交表明生长素在花药中合成。与生长素作用的时间一致，TIR1、AFB1、AFB2 和 AFB3 生长素受体编码基因仅在减数分裂末期开始的发育后期在花药中转录。我们发现，在 tir1 afb 三重和四重突变体中，花药开裂和花粉成熟发生得早于野生型，导致成熟花粉粒在花丝伸长完成之前释放。我们还评估了生长素运输对晚期雄蕊发育过程的贡献。我们的结果表明，花药中合成的生长素在协调花药开裂和花粉成熟中起主要作用，而生长素运输有助于花前花丝伸长的独立调节。
We provide evidence on the localization, synthesis, transport, and effects of auxin on the processes occurring late in Arabidopsis thaliana stamen development: anther dehiscence, pollen maturation, and preanthesis filament elongation. Expression of auxin-sensitive reporter constructs suggests that auxin effects begin in anthers between the end of meiosis and the bilocular stage in the somatic tissues involved in the first step of dehiscence as well as in the microspores and in the junction region between anther and filament. In situ hybridizations of the auxin biosynthetic genes YUC2 and YUC6 suggest that auxin is synthesized in anthers. In agreement with the timing of auxin effects, the TIR1, AFB1, AFB2, and AFB3 auxin receptor-encoding genes are transcribed in anthers only during late stages of development starting at the end of meiosis. We found that in tir1 afb triple and quadruple mutants, anther dehiscence and pollen maturation occur earlier than in the wild type, causing the release of mature pollen grains before the completion of filament elongation. We also assessed the contribution of auxin transport to late stamen developmental processes. Our results suggest that auxin synthesized in anthers plays a major role in coordinating anther dehiscence and pollen maturation, while auxin transport contributes to the independent regulation of preanthesis filament elongation.