植物表皮毛发育控制基因GL2遗传互作因子的筛选和鉴定

Screening and Identification of New Genetic Factors Interacting with GL2 During Plant Trichome Development

表皮毛广泛存在于陆生植物的地上部分,是植物与环境之间的一道天然屏障,具有多种重要的生物学功能。拟南芥HD-Zip家族转录因子GLABRA 2(GL2)是调控表皮毛形成和发育的关键因子,通过筛选和鉴定GL2的遗传互作因子,可以为进一步研究植物表皮毛发育调控的分子机制奠定基础。通过大规模的遗传筛选和图位克隆,获得了一个叶片上完全没有表皮毛的突变体M12-01,遗传分析表明M12-01 single突变表型受隐性单核基因控制。M12-01 single突变体表型与拟南芥TRANSPARENT TESTA GLABKA 1(TTG1)基因的功能缺失突变体表型相似。对TTG1基因的测序结果显示其+445位碱基由鸟嘌呤突变为腺嘌呤,从而使编码的甘氨酸变为精氨酸。本研究证实TTG1突变能增强gl2-3突变体的表型,GL2基因与TTG1基因之间存在遗传互作,这为进一步研究GL2调控植物表皮毛发育的分子机制提供了新的遗传材料。

Trichomes widely exist on aboveground parts of terrestrial plants,exhibiting as natural barriers between plants and theenvironment,and also servering many biological functions. The transcription factor GLABRA 2（GL2）is a key factor regulating trichomeinitiation and the following developmental processes. Screening and identification of new GL2 interactors will lay a foundation for furtheruncovering the regulatory molecular mechanisms of trichome development. Through large-scale genetic screening and cloning,a new mutantM12-01 without trichome in the leaves was found,and genetic analysis indicated that the phenotype of M12-01 single mutant was controlled by arecessive single nuclear gene. The phenotype of M12-01 single mutant was similar to that of functional deletion mutant of Arabidopsis TTG1 gene.Sequencing TTG1 gene revealed that a single nucleotide replacement from guanine to adenine in ＋445 of TTG1 gene occurred,which resultedin the encoded glycine changed to arginine. This work confirmed that mutation of TTG1 enhanced the phenotype of gl2-3 mutant,and geneticinteraction between gene GL2 and TTG1,which provides new genetic materials for further studying the molecular mechanism of GL2 regulationon the development of plant trichome.