柑橘褐斑病菌AaSIP2基因生物学功能初步研究  

Preliminary Studies on the Function of AaSIP2 Gene in the Tangerine Pathotype of Alternaria alternata

作　　者：唐飞艳[1] 孔向雯 吕韦玮 唐科志[1] TANG Feiyan;KONG Xiangwen;Lü Weiwei;TANG Kezhi(Citrus Research Institute,Southwest University,Chinese Academy of Agricultural Sciences,Chongqing 400712,China)

机构地区：[1]西南大学柑桔研究所,中国农业科学院柑桔研究所,重庆400712

出　　处：《园艺学报》2018年第12期2358-2370,共13页Acta Horticulturae Sinica

基　　金：教育部创新团队项目(IRT0976);重庆市科技攻关项目(CSTC2012GG-YYJS0475).

摘　　要：蔗糖非发酵(Sucrose non-fermenting 1,SNF1)蛋白激酶复合体是1个对真菌生长发育和致病力发挥重要作用且高度保守的异源三聚体蛋白,包含1个催化亚基α,两个调节亚基β、γ。前期研究表明,α亚基Snf1在柑橘褐斑病菌碳源利用和致病力方面具有重要作用。为了解SNF1复合体其他亚基在柑橘褐斑病菌中的功能,对柑橘褐斑病菌AlternariaalternataZ7菌株的蛋白序列进行搜索,鉴定到1个β亚基Sip2。通过基因敲除及回补技术,分析AaSIP2在柑橘褐斑病菌中生物学功能。结果显示,与野生型和回补菌株相比,AaSIP2缺失突变体产孢量降低且孢子萌发迟缓,对糖和KCl、CaCl_2胁迫更敏感;在不同单一碳源的MM培养基上生长速度受到不同程度抑制;对寄主的致病能力显著降低。初步证明AaSIP2参与调控柑橘褐斑病菌的产孢、孢子萌发、胁迫应答、碳源利用及致病性。The sucrose non-fermenting 1(SNF1)protein kinase complex is a highly conserved heterotrimeric protein,including a catalytic subunit α and two regulatory subunits(β,γ),which plays an important role in fungal development and virulence. Our previous study revealed that catalytic subunit α of the tangerine pathotype of Alternaria alternata plays a crucial part in the utilization of alternative carbon sources and virulence. In order to determine the functions of other subunits of the SNF1 complex in the tangerine pathotype of A. alternata,we studied the protein sequence of the tangerine pathotype of A. alternata strain Z7 and identified one β subunit(AaSIP2). The biological functions of AaSIP2 were characterized using gene knock-out and complementation strategy. The results showed that the mutants had less conidia and slower spore germination,more sensitive to sugar and partial salt stress compared with the wild type and complementary strain. The vegetative growth of the ΔAaSip2 mutants were reduced in MM medium with different single carbon sources. Additionally,virulence assays revealed that ΔAaSip2 induced significantly reduced necrotic lesions on detached citrus leaves. In conclution,we reveal that AaSIP2 is required for utilization of carbon source,conidiation,spore germination,stress response and virulence in A. alternata.

关 键 词：柑橘 柑橘褐斑病菌 蔗糖非发酵蛋白激酶 AaSIP2基因 碳源利用 致病性 

分 类 号：S666[农业科学—果树学]