OsMS1 functions as a transcriptional activator to regulate programmed tapetum development and pollen exine formation in rice
OsMS1 functions as a transcriptional activator to regulate programmed tapetum development and pollen exine formation in rice
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OsMS1 作为转录激活因子调节水稻绒毡层的程序化发育和花粉外壁的形成
DOI：
10.1007/s11103-018-0811-0
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发表时间：
2019-01-01
影响因子：
5.1
通讯作者：
Cheng, Shihua
中科院分区：
文献类型：
--
作者：
Yang, Zhengfu;Liu, Ling;Cheng, Shihua
OsMS1作为转录激活因子，通过其植物同源结构域(PHD)调控水稻绒毡层程序性细胞死亡(PCD)和花粉外壁形成，与已知的绒毡层调控因子相互作用。绒毡层是雄蕊中的标志组织，在减数分裂后花药发育过程中经历PCD引发的退化。这种降解过程对于花药角质层和花粉外壁的形成是必不可少的。先前的研究表明，PTC1在绒毛膜PCD的调节中起着关键作用。然而，目前尚不清楚这是如何发生的。为了进一步研究该基因在水稻中的作用，我们利用CRISPR/Cas9系统产生了一个纯合子突变体osms1，它完全雄性不育，花药略黄，花药小，花粉粒看不见。此外，细胞学观察显示，在osms1突变体的花药中，细胞学观察显示绒毡层PCD延迟，花粉外壁形成缺陷，缺乏DNA片段化。OsMS1编码PhD指蛋白，位于水稻原生质体的核内，是一种具有转录激活活性的转录因子。Y2H和BIFC分析表明，OsMS1可以与OsMADS15和TDR相互作用蛋白2(TIP2)相互作用。据报道，TIP2与TDR协同调控EAT1的表达，进而调节水稻绒毛膜PCD的表达。定量聚合酶链式反应结果表明，在osms1突变体中，与绒毡层PCD和花粉壁生物合成相关的基因EAT1、AP37、AP25、OsC6和OsC4的表达显著降低。综上所述，我们的结果表明，OsMS1通过其PhD手指与已知的绒毡层调控因子相互作用，调控水稻绒毡层PCD和花粉外壁的形成。
OsMS1 functions as a transcriptional activator and interacts with known tapetal regulatory factors through its plant homeodomain (PHD) regulating tapetal programmed cell death (PCD) and pollen exine formation in rice. The tapetum, a hallmark tissue in the stamen, undergoes degradation triggered by PCD during post-meiotic anther development. This degradation process is indispensable for anther cuticle and pollen exine formation. Previous study has shown that PTC1 plays a critical role in the regulation of tapetal PCD. However, it remained unclear how this occurs. To further investigate the role of this gene in rice, we used CRISPR/Cas9 system to generate the homozygous mutant named as osms1, which showed complete male sterility with slightly yellow and small anthers, as well as invisible pollen grains. In addition, cytological observation revealed delayed tapetal PCD, defective pollen exine formation and a lack of DNA fragmentation according to a TUNEL analysis in the anthers of osms1 mutant. OsMS1, which encodes a PHD finger protein, was located in the nucleus of rice protoplasts and functioned as a transcription factor with transcriptional activation activity. Y2H and BiFC assays demonstrated that OsMS1 can interact with OsMADS15 and TDR INTERACTING PROTEIN2 (TIP2). It has been reported that TIP2 coordinated with TDR to modulate the expression of EAT1 and further regulated tapetal PCD in rice. Results of qPCR suggested that the expression of the genes associated with tapetal PCD and pollen wall biosynthesis, such as EAT1, AP37, AP25, OsC6 and OsC4, were significantly reduced in osms1 mutant. Taken together, our results demonstrate that the interaction of OsMS1 with known tapetal regulatory factors through its PHD finger regulates tapetal PCD and pollen exine formation in rice.