摘要：近日，来自华中农业大学园艺林学学院的研究人员在美国《国家科学院院刊》（PNAS）上发表了题为“A regulatory gene induces trichome formation and embryo lethality in tomato”（番茄表皮毛形成及胚胎致死的调控机制）的论文。
论文的第一作者为华中农业大学园艺林学学院的硕博连读生杨长宪，通讯作者为该院叶志彪教授。叶志彪教授现任职作物遗传改良国家重点实验室和国家农作物分子育种中心固定研究人员，国家植物基因中心（武汉）研究人员，享受国务院政府特殊津贴，国家“863”计划“十五周年”先进个人。先后主持国家自然科学基金、国家863计划、国家发改委、“948”等科研项目30余项。先后获得部省级科技进步奖励4项，授权发明专利2项，申请专利5项，审定品种3项。发表论文和专著80余篇，其中SCI收录论文15篇。
陆地植物表皮毛起始于植物表皮细胞，它们有单细胞和多细胞两种类型。表皮毛作为研究植物细胞命运调控的模式系统，越来越受到人们的重视。拟南芥表皮毛作为典型的单细胞结构，其调控机制已经进行了深入的研究，即通过MYB-bHLH-WD40 蛋白复合体调节下游基因的表达，从而控制表皮毛的分化发育。棉花纤维与拟南芥表皮毛发生机制相似。然而科学家们对于番茄、矮牵牛、烟草等体表的多细胞表皮毛起始分化的调控机制还不是很清楚。
在这篇文章中，研究人员通过图位克隆的方法分离并鉴定了番茄多细胞表皮毛形成的关键基因—Woolly (Wo)，并深入研究了该基因参与番茄表皮毛形成的调控途径，即Wo通过蛋白互作的方式促进细胞周期相关基因—SlCycB2 的表达，从而促使细胞从G2期向M期的转换，最终促进表皮毛的形成。同时，由于Wo基因纯合后会导致番茄胚胎的败育，因此该基因的分离对于揭示番茄胚胎发育的机理也具有重要意义。
新研究结果表明番茄表皮毛形成的调控模式不同于拟南芥表皮毛，是一种新的调控机制。该机制的发现对于揭示植物细胞命运调控的多样性具有十分重要的价值。
另外，番茄表皮毛在抵抗蚜虫及其传播的黄瓜花叶病毒、烟草花叶病毒、黄化曲叶病毒等方面发挥重要作用。目前我国已培育出多个多毛番茄品种应用于生产，但因多毛的发生与胚胎纯合子致死相关联，所培育出来的番茄一代杂交品种总是为“多毛”和“无毛”两类植株的混合群体，种植需剔除“无毛”的植株。该研究对破解“多毛”与“纯合子致死”难题奠定了基础。
生物探索推荐英文论文摘要：
A regulatory gene induces trichome formation and embryo lethality in tomato
Abstract
Trichomes are universal biological structures originating from the aerial epidermis, which serve as an excellent model to study plant differentiation at the cell level. Although the pathway regulating trichome formation in the Rosids has been well characterized, only very recently a few genes were identified for trichome initiation in the Asterids. In this study, we cloned Woolly (Wo), essential for trichome formation in tomato. Transgenic experiments revealed that the woolly phenotype is caused by the mutation in Wo which encodes a homeodomain protein containing a bZIP motif and a START domain. We identified three alleles of Wo and found that each allele contains a missense mutation, which respectively results in an amino acid substitution at the C terminus. Microarray and expression analysis showed that the expression of a B-type cyclin gene, SlCycB2, is possibly regulated by Wo, which also participates in trichome formation. Suppression of Wo or SlCycB2 expression by RNAi decreased the number of type I trichomes, and direct protein–protein interaction was detected between them, implying that both proteins may work together in the regulation of this type of trichome formation. Cytological observation and Wo transcript analysis in the developing seeds showed that embryo development was also correlated with Wo.
