Investigation of the origin of the AM-toxin biosynthetic gene cluster in Alternaria alternata apple pathotype

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K14662
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Plant protection science
• Research Institution: Nagoya University
• Principal Investigator: Tsuge Takashi 名古屋大学, 生命農学研究科, 教授 (30192644)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 植物病原菌 / 菌類 / 植物 / 病原性 / 進化 / 宿主特異的毒素

Outline of Final Research Achievements

The apple pathotype of Alternaria alternata produces host-specific AM-toxin and causes Alternaria blotch on apple cultivars sensitive to AM-toxin. We previously found that seven of 12 AM-toxin biosynthetic genes (AMT genes) were generated via horizontal gene transfer from Mycosphaerella species. In this study, we analyzed structure and function of the AMT homologs (MgAMT genes) of Mycosphaerella graminicola. Structural analysis of the genomic region including the MgAMT genes found that the 90-kb region encodes seven MgAMT genes and six additional genes possibly involved in secondary metabolism. RT-PCR analysis showed that genes in this region were expressed in wheat leaves inoculated with the pathogen conidia from the early stage of infection. We also observed toxicity of culture filtrates of the pathogen to wheat leaves. These results suggest that M. graminicola produces toxic substance similar in structure to AM-toxin.

Free Research Field

植物病理学