冠突曲霉flbD基因功能研究

冠突曲霉是茯砖茶上的优势菌,可通过渗透压调控获得纯的无性和有性阶段,是研究真菌产孢的好材料。flbD基因广泛存在于丝状真菌中,是调控丝状真菌无性孢子形成的关键基因。为了探究flbD基因在冠突曲霉(Aspergillus cristatus)发育阶段的功能,以冠突曲霉为试验材料,构建flbD基因敲除载体,利用根癌农杆菌介导转化,筛选得到flbD基因敲除菌株。通过对ΔflbD敲除株和野生型菌株的比较观察发现:野生型的分生孢子数量是敲除株的4.7倍,而子囊孢子数量相差不大;在不同渗透压培养基上,ΔflbD突变株的菌丝生长速率与野生型的没有明显差异,但是突变株会产生大量“棉花”状的气生菌丝;在高渗条件下,ΔflbD突变株分生孢子的产生有延迟现象。运用基因敲除技术检验了flbD基因在冠突曲霉的功能,结果显示flbD对冠突曲霉的无性产孢起正调控作用,敲除flbD基因将减少无性孢子的形成。此研究对开展冠突曲霉无性产孢的研究具有重要借鉴价值。

Characterization of the flagellar biosynthesis regulatory gene flbD in Azospirillum brasilense

A flagellar gene cluster fragment includingflbD of Azospirillum brasilense was cloned and sequenced. TheflbD mutant strain was found to be nonmotile——losingboth polar and lateral flagella (Fla-Laf-). Motility and fla-gella were regained by complementation with plasmid-borne multicopy flbD, but altered with larger swarming circle and fewer lateral flagella on the semisolid plate. This result indicated that FlbD plays an important role in the regulation of both polar and lateral flagellar biosynthesis in A. brasilense.