北大许智宏、白书农教授最新综述重新定义植物性别与性别分化

　　

性别分化是生物中普遍存在的一个自然现象。多年来，植物科学领域中的主导观念一直认为，通过对单性花的研究可以帮助我们揭示植物性别分化的调控机制。

在针对黄瓜单性花发育的过程及调控机制所做的多年研究基础上，许智宏、白书农教授应International Review of Cell and Molecular Biology编委会的邀请，撰写了长篇综述并于近日发表。

该综述在总结其实验室黄瓜单性花研究工作的同时，系统阐述了他们对性别和性别分化的本质、动植物性别分化策略的差别及其可能的原因、有性生殖周期概念及其在生命活动中的意义、植物发育单位概念及其与植物生活周期核心过程之间的关系、植物性别分化机制的渐进式模型等方面的思考。他们认为，前人用单性花来表示植物性别的观念存在时代的局限性。这种观念在当时有其合理性，但随着对研究的深入，各种证据表明，单性花是一种避免自交以增加变异和适应性的机制，并不涉及性别分化问题。他们在综述中提出，性别在本质上是一种配子异型现象、性别分化是在源于合子的体细胞中发生的指向异型配子的分岔点形成事件。

该综述中所提出的很多新观念对人们理解植物生命活动的内在规律提供了一个新的视角，同时也为探讨植物性别分化的调控机制提出了新的研究思路和策略。该文是一篇近年少见的侧重思考的综述，相信对相关领域的师生及研究者都会有所启迪。

原文摘要：

Unisexual Cucumber Flowers, Sex and Sex Differentiation

Sex is a universal phenomenon in the world of eukaryotes. Attempts have been made to understand regulatory mechanisms for plant sex determination by investigating unisexual flowers. The cucumber plant is one of the model systems for studying how sex determination is regulated by phytohormones. A systematic investigation of the development of unisexual cucumber flowers is summarized here, and it is suggested that the mechanism of the unisexual flower can help us to understand how the process leading to one type of gametogenesis is prevented. Based on these findings, we concluded that the unisexual cucumber flowers is not an issue of sex differentiation, but instead a mechanism for avoiding self-pollination. Sex differentiation is essentially the divergent point(s) leading to heterogametogenesis. On the basis of analyses of sex differentiation in unicellular organisms and animals as well as the core process of plant life cycle, a concept of “sexual reproduction cycle” is proposed for understanding the essential role of sex and a “progressive model” for future investigations of sex differentiation in plants.