Kiwifruit (Actinidia spp) is a dioecious plant, where male and female flowers set on distinct individuals, with an XY (heterogametic male) sex-determining system. However, the genetic sex determinants have remained unidentified until now. Akagi et al. (pages 780–795) identified a candidate gene encoding a type-C cytokinin response regulator, named Shy Girl, located on the Y chromosome. It is specifically expressed in female organs and suppresses their development, resulting in male flowers. An Actinidia-specific duplication event gave rise to two copies of this kind of gene, which then evolved independently and one became Shy Girl by developing a new expression pattern to act as a sex determinant. This work provides an example of how a lineage-specific duplication event can provide a template for the evolution of new functions that affect key biological processes, such as sex determination. The cover image shows female kiwifruit flowers.
PLANT CELL: 华南师范大学解析调控种子成熟及油脂合成的分子机制
WRINKLED1 (WRI1)是一个调控植物种子油脂合成的关键转录因子。但是目前关于WRI1在油脂合成中如何调控基因表达尚不清楚。
本研究从蛋白质相互作用入手，发现WRI1可以与一个在拟南芥种子成熟过程中表达的BLISTER (BLI)发生相互作用，突变体bli的种子成熟延迟，种子皱缩且油脂含量显著下降，这与wri1的表型非常类似。
而BLI的过表达株系则种子变大且油脂含量显著增高。
基因表达以及遗传分析显示，BLI在WRI对其参与脂肪酸合成以及种子成熟相关基因表达的过程中发挥重要作用。BLI可以被WRI1招募至脂肪酸合成相关基因启动子的AW boxes处。此外，BLI可以与两个参与nucleosomal occupancy and histone modifications的基因Polycomb-group protein CURLY LEAF (CLF) or the chromatin remodeling factor SWITCH/SUCROSE NONFERMENTING 3B (SWI3B)发生相互作用。
小结：本研究揭示了WRI1–BLI–CLF–SWI3B模块在调控种子成熟以及油脂合成过程中的作用。
原文题目：BLISTER promotes seed maturation and fatty acid biosynthesis by interacting with WRINKLED1 to regulate chromatin dynamics in Arabidopsis
