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

• 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
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2016: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• 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.

Research Products

• [Journal Article] 宿主特異的毒素研究 (2016)
  • Author(s): 柘植尚志
  • Journal Title: 植物感染生理談話会論文集：感染生理談話会の50年～古きを温ねて、新しきを知る～ Volume: 51 Pages: 57-69
  • Acknowledgement Compliant
• [Journal Article] The global regulator LaeA controls biosynthesis of host-specific toxins, pathogenicity and development of Alternaria alternata pathotypes (2016)
  • Author(s): Takao, K., Akagi, Y., Tsuge, T., Harimoto, Y., Yamamoto, M., and Kodama, M.
  • Journal Title: Journal of General Plant Pathology Volume: 82 Issue: 3 Pages: 121-131
  • DOI: 10.1007/s10327-016-0656-9
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Mycosphaerella属菌ゲノムに存在するリンゴ斑点落葉病菌のAM毒素生合成遺伝子クラスターの相同領域 (2016)
  • Author(s): 森 汐理、宮川泰輝、後藤千保、川瀬めぐみ、播本佳明、花田耕介、児玉基一朗、山本幹博、柘植尚志
  • Organizer: 日本植物病理学会関西部会
  • Place of Presentation: 静岡県コンベンションアーツセンター グランシップ
  • Year and Date: 2016-08-29
• [Presentation] 宿主特異的毒素研究 (2016)
  • Author(s): 柘植尚志
  • Organizer: 日本植物病理学会植物感染生理談話会
  • Place of Presentation: 神戸市須磨浦海岸 シーパル須磨
  • Year and Date: 2016-08-10
  • Invited
• [Presentation] 非病原性Alternaria alternata におけるconditionally dispensable chromosome様染色体の構造解析 (2016)
  • Author(s): 赤木靖典，柘植尚志，有江力，児玉基一朗
  • Organizer: 日本植物病理学会大会
  • Place of Presentation: 岡山コンベンションホール，岡山県岡山市
  • Year and Date: 2016-03-21
• [Presentation] Evolution of pathogenicity controlled by small dispensable chromosomes in Alternaria alternata pathogens (2015)
  • Author(s): Tsuge, T., Harimoto, Y., Akagi, Y., Hanada, K., Kodama, M., Akimitsu, K., and Yamamoto, M.
  • Organizer: US-Japan Cooperative Science Seminar "Molecular Contact Points in Host-Pathogen Co-evolution”
  • Place of Presentation: 高松コンベンションホール，香川県高松市
  • Year and Date: 2015-10-25
  • Int'l Joint Research / Invited
• [Presentation] Alternaria alternata病原型が保有するconditionally dispensable chromosomeの起源 (2015)
  • Author(s): 赤木靖典，柘植尚志，有江力，児玉基一朗
  • Organizer: 日本植物病理学会関西部会
  • Place of Presentation: 岡山コンベンションホール，岡山県岡山市
  • Year and Date: 2015-09-29