生长素响应因子ARFs调节月季花瓣离区形成的机理解析

Rose is one of the most important cut flowers among ornamental plants. The opening and longevity of rose flower is a major factor in determining the ornamental value of rose flower. Moreover, the rose floral longevity is relative to the timing of petal shedding occurrence. Our preliminary results showed that silencing of ARFs in rose had defects in formation of petal abscission zone (AZ). In this project, we attempt to investigate the roles of ARFs involved in rose petal AZ differentiation. The downstream genes and interacting proteins of ARFs involved in the abscission will be isolated for dissecting the regulatory pathway of ARF networks. This project will shed light on molecular regulatory mechanisms of ARFs in AZ formation at both transcriptional and post-transcriptional levels, and excavate candidate genes for molecular breeding of abscission-enduring rose cultivars.

月季是世界范围应用最广泛也是商品价值最高的鲜切花，其观赏价值主要取决于花朵的开放寿命，而花朵的开放寿命又由花瓣脱落的时间决定。因此，认知花瓣脱落机理，选育花瓣不易脱落型月季新种质，成为月季品种创制新的研究热点。申请者近期的研究发现，生长素响应因子ARF基因家族成员在月季中的沉默能够导致花瓣离区不同程度的缺失，从而抑制月季花瓣的脱落。基于此，本项目拟分析ARF重要成员对花瓣离层形成的影响，从转录和转录后层面，系统探索ARFs在花瓣离层形成上的分子调节机理，为月季花瓣脱落性状改良育种提供基因储备。

月季是世界范围应用最广泛也是商品价值最高的鲜切花之一，其观赏价值主要取决于花朵的开放寿命，而花朵的开放寿命又由花瓣脱落的时间决定。本项目从生长素响应因子ARF家族成员的筛选、表型分析及作用机理入手，系统探讨关键ARF因子调节花瓣离区形成和激活的调节机制。我们的研究发现，RhARF7基因的表达随花朵开放而降低表达，沉默RhARF7基因促进了月季花瓣脱落进程。RhARF7能够直接调控蔗糖运输基因RhSUC2的表达，进而调控离区中的蔗糖运输。该结果为阐明生长素和蔗糖互作调控花瓣脱落的分子机制奠定了理论基础，也为月季花瓣脱落性状改良育种提供基因储备。