MOLECULAR BASIS FOR SPECIALIZATION AND EVOLUTION OF PATHOGENICITY IN ALTERNARIA PATHOGENS THAT HOST-SPECIFIC TOXINS INVOLVE IN

宿主特异性毒素参与的链格孢病原体致病性特化和进化的分子基础

• 批准号: 05404010
• 负责人: KOHMOTO Keisuke
• 金额: $ 17.22万
• 依托单位: TOTTORI UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (A)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05404010/
• 关键词: Host-specific toxin; Alternaria toxins; Alternaria alternata; Host specificity; Gene tagging by REMI; Electrophoretic karyotyping; cyclic peptide synthetase; Host Specificity; 宿主特異的毒素; 病原性遺伝子; RFLP分析; ACT毒素; AK毒素; AF毒素; AL毒素

A new host-specific toxin (HST) was isolated from Australian strains of brown spot pathogen of tangerine, determined the structure, and named ACT-toxin IIIb. A rapid and sensitive procedure of AL-toxin determination was established. A key role of HSTs in host recognition by fungal pathogens was investigated in relation to plant defense reactins. For cloning gene (s) involved in biosynthesis of such HST,protoplasts of different pathotypes of Alternaria alternata were transformed utilizing ectopic integration of pAN7-1 plasmid carrying hph, gpd, and trpC genes in the presence of restriction enzymes. Several transformants were found lacked the ability to produce HSTs, and found they randomly have a single copy of pAN7-1 integrated at single site. Isolation of DNA fragments containing HST synthesis gene (s) by rescuing the integrated plasmid DNA with a flanking genomic sequence from HST-deficient transformants may possible. Electrophoretic karyotyping suggested that A.alternata has 8 to 9 chromosomes ranging from 0.6 Mb to 5.5 Mb, and its total genomesize probably is 22-24Mb. B-chromosomes might be correlated to specific pathogenicity of each pathotype. Some A.alternata have incompatibility in cell fusion.

从澳大利亚柑橘褐斑病菌菌株中分离出一种新的宿主特异性毒素（HST），确定了结构，并将其命名为ACT-毒素IIIb。建立了快速、灵敏的 AL 毒素测定程序。研究了 HST 在真菌病原体宿主识别中与植物防御反应相关的关键作用。为了克隆参与此类HST生物合成的基因，利用携带hph、gpd和trpC基因的pAN7-1质粒在限制酶存在下进行异位整合来转化不同病型的链格孢的原生质体。发现几个转化体缺乏产生 HST 的能力，并且发现它们在单个位点随机整合有一个 pAN7-1 的单个拷贝。通过从 HST 缺陷型转化体中拯救带有侧翼基因组序列的整合质粒 DNA，分离含有 HST 合成基因的 DNA 片段是可能的。电泳核型分析表明，A.alternata有8至9条染色体，范围为0.6 Mb至5.5 Mb，其总基因组大小可能为22-24 Mb。 B 染色体可能与每种致病型的特定致病性相关。有些链格孢菌在细胞融合方面存在不相容性。

项目成果

Wada,H.,et al.: "Occurrence of the strawberry pathotype of Alternaria alternata in Italy" Plant Disease. 80(in press). (1996)

Wada,H.,et al.：“意大利草莓致病型链格孢菌的发生”植物病害。

Kohmoto, K., Singh, U.S., and Singh, R.P.(eds.): Pathogenesis and Host Specificity in Plant Diseases. 3-volumes.Pergamon Press, Oxford, 1145 (1995)

Kohmoto, K.、Singh, U.S. 和 Singh, R.P.（编辑）：植物病害的发病机制和宿主特异性。

Kodama, M.et al.: "A rapid and sensitive procedure for the quantitative detection of AL-toxin by fluorescence derivatization and separation by high performance liquid chromatography." Ann.Phytopathol.Soc.Japan. 61. 477-480 (1995)

Kodama, M.等人：“通过荧光衍生化和高效液相色谱分离来定量检测 AL 毒素的快速、灵敏的程序。”

Akimitsu,K.,et al.: "Light suppresses the action of the host-specific ACR-toxin on citrus leaves" J.Fac.Agric.Tottori Univ.30. (1994)

Akimitsu,K.,et al.：“光抑制柑橘叶上宿主特异性 ACR 毒素的作用”J.Fac.Agric.Tottori Univ.30。

Kodama, M.et al.: "Cultivar-specific and non-specific responses in tomato cell cultures to AL-toxin from Alternaria alternata tmato pathotype." Ann.Phytopathol.Soc.Japan. 61. 582-585 (1995)

Kodama, M.等人：“番茄细胞培养物对来自链格孢菌 tmato 致病型的 AL 毒素的品种特异性和非特异性反应。”