记者从中科院华南植物园获悉，该园植物激素调控组助理研究员刘旭博士在侯兴亮研究员的指导下，发现NUCLEAR FACTOR Y-C（NF-YC）家族基因在调控植物种子萌发中发挥重要作用。相关研究近日在线发表于《自然—通讯》。

种子萌发是植物发育的一个重要阶段，决定着植物何时何地开启生长阶段。众多研究表明，种子萌发主要通过植物内源激素GA和ABA的相互制衡方式调节，然而这两种激素之间发生拮抗的具体分子机制迄今尚未阐释清楚。

研究人员发现，拟南芥NF-YC负调控GA介导种子萌发过程，在GA合成抑制剂（PAC）处理下，NF-YC同源基因多突变体的种子萌发率相比野生型显著提高，表现为PAC不敏感，而过表达NF-YC株系的种子对PAC超敏感。他们利用分子生物学手段找到了NF-YC的互作因子，即GA介导种子萌发关键抑制子DELLA蛋白RGL2。

研究证实NF-YC和RGL2在转录调控上具有相互依赖关系，二者共同结合到ABA信号关键因子ABI5基因启动子的CCAAT元件上促进其转录，以此来协同GA和ABA信号来介导种子萌发的调控。（来源：中国科学报 朱汉斌 周飞）

The NF-YC–RGL2 module integrates GA and ABA signalling to regulate seed germination in Arabidopsis

Abstract  The antagonistic crosstalk between gibberellic acid (GA) and abscisic acid (ABA) plays a pivotal role in the modulation of seed germination. However, the molecular mechanism of such phytohormone interaction remains largely elusive. Here we show that three Arabidopsis NUCLEAR FACTOR-Y C (NF-YC) homologues NF-YC3, NF-YC4 and NF-YC9 redundantly modulate GA- and ABA-mediated seed germination. These NF-YCs interact with the DELLA protein RGL2, a key repressor of GA signalling. The NF-YC–RGL2 module targets ABI5, a gene encoding a core component of ABA signalling, via specific CCAAT elements and collectively regulates a set of GA- and ABA-responsive genes, thus controlling germination. These results suggest that the NF-YC–RGL2–ABI5 module integrates GA and ABA signalling pathways during seed germination.

原文链接：http://www.nature.com/articles/ncomms12768