国内において樹木病原性卵菌類による深刻な病害が発生しない要因の解明

日本树木病原卵菌引起严重疾病预防因素的阐明

• 批准号: 22K14917
• 负责人: 日恵野 綾香
• 金额: $ 2.91万
• 依托单位: Gifu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Early-Career Scientists
• 财政年份: 2022
• 资助国家: 日本
• 起止时间: 2022-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-22K14917/
• 关键词: 植物組織の分解力; 糖質関連酵素; 卵菌類; フーリエ変換赤外分光法; ゲノム解析

植物病原菌にとって植物組織を分解する力は感染サイクルのあらゆる段階（植物体への侵入，栄養の摂取，離脱など）に欠かせない性質である．植物病原性卵菌類では，特定の糖質関連酵素ファミリーに属する遺伝子が感染時特異的に発現すること，幼苗期に感染して立ち枯れを引き起こす比較的病原性の弱い卵菌類がある種の糖質関連酵素遺伝子を欠くことが知られている．卵菌類の環境分離菌株がもつ植物組織の分解力を評価するため，代表菌株の選定，分解試験，フーリエ変換赤外分光（FT-IR）分析による分解度の評価を行った．分解試験に供する菌株は遺伝的に同一であるものの重複を避けるため，同じ環境試料から分離された同種の菌株についてはいずれか1菌株を代表とした．過去5年以内に国内で分離された約1500菌株から選抜を行い，約400菌株を代表として選んだ．分解試験に用いる植物はスギ，ヒノキ，ケヤキ，コナラとした．30 cm前後の苗木数本から直径2 mm未満の根を回収し，液体窒素で凍結したのち乳鉢と乳棒で粉砕し，高圧蒸気滅菌して分解試験に用いた．24穴プレートに根の粉末と滅菌水を入れ，含菌寒天を接種し，１か月間20℃の室内に静置して分解させた．その後，含菌寒天を除去して根の粉末を風乾し，FT-IR分析により分解度を評価した．FT-IR分析においては，水分，接種に用いた含菌寒天の培地成分，菌体の細胞壁成分が測定結果にもたらす影響を考慮した評価とするため，分解試験後に根の粉末を充分に乾燥させるとともに，滅菌水，V8寒天培地，菌体について単独のスペクトルを取得し参照することとした．

Plant pathogens are responsible for the decomposition of plant tissues, the ability to infect, and the nature of plant pathogens. Plant pathogenic oomycetes have specific glycogen-related enzyme genes that are specific to infection, and less pathogenic oomycetes have specific glycogen-related enzyme genes that are not known during seedling stage infection. Evaluation of decomposition ability of plant tissues by environmental isolates of egg fungi, selection of representative strains, decomposition test, FT-IR analysis. The same environmental sample was isolated from the same strain. About 1500 strains have been isolated in China in the past 5 years, and about 400 strains represent the selection. In the decomposition test, the plant was inoculated with water, and the seedlings before and after 30 cm were inoculated with water. The seedlings were 2 mm in diameter, and the roots were not recovered. The liquid was frozen and the powder was added. The decomposition test was sterilized by high pressure steam. The roots were inoculated with sterilized water. The seedlings were inoculated with bacteria in cold weather. The seedlings were still decomposed in the room at 20℃ for 1 month. After the bacteria were removed, the root powder was air-dried, FT-IR analysis was performed, and the decomposition degree was evaluated.FT-IR analysis was performed, and the moisture content, the inoculation time, the culture time, and the cell wall composition of the bacteria were determined. The influence of the evaluation was considered. After the decomposition test, the root powder was fully dried. The bacteria were isolated from the soil.