Laboratory of Cell & Molecular Biology, Institute of Vegetable Science, Zhejiang University, Hangzhou, 310058, China; Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agriculture, Hangzhou, 310058, China; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, 310058, China.
Biochem Biophys Res Commun. 2019 Oct 22;518(4):726-731. doi: 10.1016/j.bbrc.2019.08.119. Epub 2019 Aug 28.
In flowering plants, stamen development is a complex multistage process, which is highly regulated by a series of transcription factors. In this study, BcMF28, which encodes a R2R3-MYB transcription factor, was isolated from Brassica campestris. BcMF28 is localized in the nucleus and cytoplasm, and acts as a transcriptional activator. Quantitative real-time PCR and promoter activity analysis revealed that BcMF28 was predominately expressed in inflorescences. The expression of BcMF28 was specifically detected in tapetum, developing microspores, anther endothecium, and filaments during late stamen development. The overexpression of BcMF28 in Arabidopsis resulted in aberrant stamen development, including filament shortening, anther indehiscence, and pollen abortion. Detailed analysis of anther development in transgenic plants revealed that the degeneration of septum and stomium did not occur, and endothecium lignification was affected. Furthermore, the expression levels of genes involved in the phenylpropanoid metabolism pathway were altered in BcMF28-overexpressing transgenic plants. Our results suggest that BcMF28 plays an important regulatory role during late stamen development.
在开花植物中，雄蕊的发育是一个复杂的多阶段过程，高度受一系列转录因子的调控。本研究从芸薹属植物中分离到编码 R2R3-MYB 转录因子的 BcMF28。BcMF28 定位于细胞核和细胞质，作为转录激活因子发挥作用。定量实时 PCR 和启动子活性分析表明，BcMF28 在花序中大量表达。BcMF28 的表达在雄蕊发育后期的绒毡层、发育中的小孢子、花药内皮层和花丝中特异性检测到。BcMF28 在拟南芥中的过表达导致雄蕊发育异常，包括花丝缩短、花药不开裂和花粉败育。对转基因植物花药发育的详细分析表明，隔膜和药室没有退化，内皮层木质化受到影响。此外，参与苯丙烷代谢途径的基因在 BcMF28 过表达转基因植物中的表达水平发生了改变。我们的研究结果表明，BcMF28 在雄蕊发育后期发挥重要的调控作用。
