基于转录组分析的哈茨木霉thga3基因功能研究

Functions of Thga3 Gene in Trichoderma harzianum Based on Transcriptome Analysis

哈茨木霉Trichoderma harzianum Th-33的Ⅲ型Gα亚基Thga3可能参与调控木霉菌的生长、产孢、几丁质酶活性、疏水性等生物学过程。为进一步明确其功能,本研究采用Hiseq2500(Illumina)测序平台,对野生菌Th-33和thga3基因敲除突变株Δthga3进行转录组测序,分析其G蛋白信号系统、细胞壁降解酶类和产孢相关基因的差异表达。与野生菌相比,Δthga3有3个G蛋白偶联受体基因发生下调表达,3个几丁质酶基因以及产孢调控基因brlA下调表达,1个G蛋白信号调控蛋白RGS1上调表达。推测thga3可能通过调控brlA的表达正调控产孢;通过调控疏水蛋白基因Tha_09745的表达调控菌丝疏水性。此外,通过调控几丁质酶基因的表达、G蛋白信号网络中其他蛋白的表达,影响菌株的拮抗和重寄生能力以及其他生物学特性。本研究为进一步探索G蛋白信号途径调控木霉菌生防特性及其机制奠定了基础。

thga3 gene encoding a type Ⅲ G protein α subunit Thga3 in Trichoderma harzianum Th-33 may participated in the regulation of growth,spore production,mycoparasitism,hydrophobic and chitinase activity.In order to clarify its function,Illumina RNA-seq technology（RNA-seq） was used to analyze the differentially expressed genes（DEGs） between the wild-type strain Th-33 and thga3 knockout mutant Δthga3,and the expression of genes related to the G protein signaling pathways,cell wall degradation enzymes,and the spore production were analysed.Comparing to wild Th-33,three DEGs of G protein receptor proteins,three chitinase genes,one sporulation regulatory gene brlA encoding a nuc leic acid binding protein and one hydrophobin gene Tha_09745 were down-regulated,and one G protein signal transduction protein gene coding RGS1 was up-regulated in Δthga3.It was hypothesized that thga3 may regulate sporulation by regulating the expression of brlA,regulate the mycelial hydrophobicity by regulat ing the expression of Tha_09745,and regulate the chitinase activity and affect the expression of other proteins in the G protein signaling network,which may affect the antagonism and mycoparasitism,as well as other biological characteristics.This study lays a foundation for further explorat ion on the regulation of G protein signaling pathway in Trichoderma biocontrol characteristics and its mechanism.