Abstract：
The Mediator complex is essential for eukaryotic transcription, yet its role and the function of its individual subunits in plants, especially in rice, remain poorly understood. Here, we investigate the function of OsMED14_2, a subunit of the Mediator tail module, in rice development. Overexpression and knockout of OsMED14_2 resulted in notable changes in panicle morphology and grain size. Microscopic analysis revealed impact of overexpression on pollen maturation, reflected by reduced viability, irregular shapes, and aberrant intine development. OsMED14_2 was found to interact with proteins involved in pollen development, namely, OsMADS62, OsMADS63 and OsMADS68, and its overexpression negatively affected the expression of OsMADS68 and the expression of other genes involved in intine development, including OsCAP1, OsGCD1, OsRIP1, and OsCPK29. Additionally, we found that OsMED14_2 overexpression influences jasmonic acid (JA) homeostasis, affecting bioactive JA levels, and expression of OsJAZ genes. Our data suggest OsMED14_2 may act as a regulator of JA-responsive genes through its interactions with OsHDAC6 and OsJAZ repressors. These findings contribute to better understanding of the Mediator complex\'s role in plant traits regulation.
摘要：
介体复合物是真核生物转录所必需的,然而它在植物中的作用和它的各个亚基的功能，尤其是在大米中，仍然知之甚少。这里,我们研究了介体尾模块的一个亚基OsMED14_2的功能，在水稻发展中。OsMED14_2的过表达和敲除导致穗部形态和晶粒尺寸的显着变化。显微镜分析显示过表达对花粉成熟的影响，反映在生存能力下降上，不规则形状,和异常的内线发育。发现OsMED14_2与参与花粉发育的蛋白质相互作用，即,OsMADS62、OsMADS63和OsMADS68及其过表达对OsMADS68的表达和其他参与intine发育的基因的表达产生负面影响,包括OsCAP1、OsGCD1、OsRIP1和OsCPK29。此外,我们发现OsMED14_2过表达影响茉莉酸（JA）稳态，影响生物活性JA水平，和OsJAZ基因的表达。我们的数据表明，OsMED14_2可能通过与OsHDAC6和OsJAZ阻遏物的相互作用充当JA响应基因的调节剂。这些发现有助于更好地理解介体复合体在植物性状调控中的作用。
