RHD3遗传互作因子突变体rren108的表型观察及遗传学分析

Phenotypic and genetic characterization of a RHD3 genetic interactor mutant rren108

根毛是植物吸收水分和养料的的重要器官,研究与根毛生长发育调控相关的基因对培育优良经济林树种具有重要意义。作为模式植物,拟南芥是一种理想的根毛研究材料。RHD3基因的主要作用在于维持根毛的顶端生长,对内质网的正常形态的维持也有重要作用。但目前对于rhd3突变体中引起根毛及内质网缺陷的机理还不是十分清楚。目前对于rhd3突变体中引起根毛及内质网缺陷的机理还尚未清楚。该研究试图通过分析对比野生型拟南芥WT、rhd3-1:GFP-HDEL及rren108双突变体根毛及细胞内质网形态,探讨RHD3调控根毛的遗传互作因子及作用机理。表型统计结果表明:rren108的平均根毛长度与rhd3-1的根毛长度差异不大,但平均根毛密度仅为rhd3-1突变体的29.5%。且rren108的根毛分布不均匀,根毛形态也发生了变异。进一步遗传分析表明,该突变性状受一对隐性单基因控制。对rhd3-1::GFP-HDEL及rren108的细胞内质网的观察表明,rren108的内质网的连接点较rhd3-1少,且其管状结构变厚呈块状,暗示rren108可能通过参与细胞内质网结构控制根毛的。

Root hairs are of great agronomic importance due to their essential roles on mineral and water uptaking in plants, therefore, searching for genes involved in root hair development and their corresponding regulatory mechanisms characterization have great potentials on breeding of non-wood forest cultivars and other plant species. As a well-studied model plant, Arabidopsis （Arabidopsis thaliana） bears a lot of advantages for root hair analysis. RHD3 was identified as an important root hair regulatory player in Arabidopsis and was found to affect the root hair morphology by root hair tip growth regulation, which is also associated with defects in ER morphology. The seeds of at present, the mechanism of causing induced hairs and endoplasmic reticulum defect in rhd3 mutants is not very clear. The study intends to compare and analyze the differences of root hair and cell endoplasmic reticulum among wild Arabidopsis thaliana WT, Arabidopsis rhd3-1：：GFP-HDEL mutant and rren 108, further explores the genetic interaction factors and interaction mechanism of RHD3 regulation to root hairs. The seeds ofArabidopsis rhd3-1：：GFP-HDEL mutant were treated with Ethyl Methane Sulfonate （EMS） and an stable double mutation line rren 108 was obtained. The phenotypic statistical results show that the average length of root hairs of rrenl08 seedlings was comparable to that of rhd3-1, but the root hair density in rren108 seedlings reduced to 29.5% compared to that of rhd3-1; The root hairs of rrenl08 were also abnormal both in morphology and distribution. The genetic analysis reveals that the root hair phenotype was controlled by a single recessive nuclear gene. The examination of the ER morphology indicates that the connection points of the endoplasmic reticulum in rrenl08 mutants were less than that of rhd3-1 mutants, and the rren108 mutants＇ tubular structure became thickened and showed a blocky state, revealing that the rren108 mutants may control the occurrence of root hair through endoplasmic reticulum structure.