报 告 人：李雅乾   农业与生物学院资源与环境系  副教授

时    间：2021年7月21日 (星期三) 12:40-14:00

地    点：农生学院创新楼（B楼）104会议室

主办单位：农生学院学科与科技办、农生学院青年教师联谊会

 

 

报告题目：  木霉菌抗菌肽合成及其调控机制研究

报告摘要：

木霉菌Trichoderma spp.是一种广泛存在于土壤环境的丝状真菌，能够产生丰富的次生代谢物，具有抑制病原菌和促植物生长等功效，在农业和医药领域有广泛应用。Peptaibols是一类由非核糖体肽合成酶（non-ribosomal peptide synthetase，NRPS)合成的富含α-氨基异丁酸（Aib）的线性、具抗菌活性及长度不等的抗菌肽，其中80%是木霉菌产生。第I类（Type I）NRPS是木霉菌中最大的生物合成基因簇，包含10个以上功能模块的NRPSs（>10,000 aa），加载约10-25个氨基酸前体合成Peptaibols类抗菌肽。这类长链抗菌肽是决定木霉抑菌活性的关键代谢产物。peptaibols的生物合成一方面受到外源添加特定氨基酸的调控，同时与生长条件（到不同氮源、碳源培养基）以及生长发育中孢子形成密切相关。甲基化转移蛋白酶LAE1是木霉菌中全局性转录调控因子，调控多种木霉菌拮抗性代谢产物形成。我们研究表明LAE1正向调节几种非核糖体肽合酶中的表达，尤其是促进NRPS1（负责19个残基peptaibols合成）的肽合酶及其侧翼基因的表达，Lae1敲除后，部分长链抗菌肽产量降低，而过表达导致木霉菌长链抗菌肽产量增加，同时产生几种新的抗菌肽。说明Lae1促进长链抗菌肽的合成，提高木霉菌抑菌活性，可以进一步对Lae1过表达株诱导并结合发酵优化提高其分泌长链抗菌肽的产量，开发抗菌肽为主要成分的新型木霉菌生防菌剂。

 

报告人简介：

报告人2009年获上海交通大学微生物学博士学位，2009-2011上海交通大学药学博士后流动站，2011年6月入职上海交通大学农业与生物学院。

【PI学科组研究方向】：

报告人所在的PI研究组主要开展木霉与病原菌互作机制方面的研究。主要研究方向如下：

（1）木霉菌中天然产物发掘

（2）木霉菌-病原菌-植物互作

（3）功能性产物发酵及产品研发

【代表性著作】： 

1. Vel1 regulates the growth of Trichoderma atroviride during co-cultivation with Bacillus amyloliquefaciens and is essential for wheat root rot control. Biological Control,2020,151:104374

2. Effect of Trichoderma harzianum on maize rhizosphere microbiome and biocontrol of Fusarium Stalk rot. 2017, Scientific Reports | 7: 1771 | DOI:10.1038/s41598-017-01680-w

3. Biodiversity of Trichoderma Community in the Tidal Flats and Wetland of Southeastern China.2016, Plos one 10.1371/journal.pone.0168020

4.木霉菌抗菌活肽peptaibols合成调控机制研究进展。菌物学报（2021年3月接收待刊）

 

ACADEMIC SALON (XXIV)

SPEAKER: Yaqian LI

Associate Professor

Department of Resource and Environment, SAB

TIME ：12:40-14:00  July 21, 2021

VENUE：Room 104, Building B, SAB

ORGANIZER：Office of Discipline and Science & Technology, SAB;

Young Teachers Association, SAB

TITLE： Synthesis and regulation of Peptaibols in Trichoderma  

ABSTRACT：

Trichoderma is a kind of filamentous fungus genus widely existing in the soil environment. These fungi produce secondary metabolites such as peptaibols that have antimicrobial activities and plant growth promoters and as commercial biofungicides in agriculture and medicine. Peptaibols are a group of special antibacterial linear peptides rich in Aib synthesized by non-ribosomal peptide synthetases (NRPSs)，approximately 80 % of the known peptaibiotics today have been found in genus Trichoderma. Type I NRPS is the largest biosynthetic gene cluster and more than 10 NRPS modules (> 10000 AA) are loaded with about 10-25 amino acid precursors to synthesize peptaibols antimicrobial peptides. These long-chain antimicrobial peptides are the crucial metabolites that dominate the antibacterial activity of Trichoderma. The biosynthesis of peptaibols is regulated by the addition of specific amino acids, and also closely related to the growth conditions (different nitrogen and carbon sources) and spore formation.  Methyltransferase Lae1 is a global transcription regulator in Trichoderma, which regulates the formation of antagonistic metabolites. Our study showed that lae1 positively regulated the expression of several non-ribosomal peptide synthases, especially the peptide synthases and their flanking genes of NRPS (ID 317983, responsible for the synthesis of 19 residues of peptaibols). After lae1 was deleted, the production of some long-chain antimicrobial peptides decreased, while overexpression lae1 increased the production of long-chain antimicrobial peptides and also several new peptaibols. These results indicated that lae1 can promote the synthesis of long-chain peptaibol and improve the antibacterial activity of Trichoderma. And lae1 over-expression strains are potential candidate for developing the new Trichoderma biocontrol agents with peptaibols as the main component,