Journal of Integrative Agriculture ›› 2022, Vol. 21 ›› Issue (7): 2019-2030.DOI: 10.1016/S2095-3119(21)63855-8

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JIA-2021-1102 漆酶基因StLAC6缺失导致玉米大斑病菌过氧化物酶体异常和药剂敏感性增加

  

  • 收稿日期:2021-06-21 接受日期:2021-10-29 出版日期:2022-07-01 发布日期:2021-10-29

Characterization of laccase gene StLAC6 involved in the pathogenicity and peroxisome function in Setosphaeria turcica

LIU Ning1 ,2*, ZHANG Qian-qian3*, JIA Hui1, ZHAO Bin1,2ZHU Zi-ping4 , CAO Zhi-yan1, 2, DONG Jin-gao1, 2   

  1. 1 State Key Laboratory of North China Crop Improvement and Regulation / Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, Baoding 071001, P.R.China

    2 College of Plant Protection, Hebei Agricultural University, Baoding 071001, P.R.China

    3 College of Life Sciences, Hebei Agriculture University, Baoding 071001, P.R.China

    4 Langfang Academy of Agriculture and Forestry Science, Langfang 065000, P.R.China

  • Received:2021-06-21 Accepted:2021-10-29 Online:2022-07-01 Published:2021-10-29
  • About author:LIU Ning, E-mail: lning121@126.com; Correspondence CAO Zhi-yan, Tel: +86-312-7528142, E-mail: caoyan208@126.com; DONG Jin-gao, Tel: +86-312-7528166, E-mail: dongjingao@126.com * These authors contributed equally to this study.
  • Supported by:
    This work was supported by the grants from the National Natural Science Foundation of China (31901827), the China Agriculture Research System (CARS-02), the Natural Science Foundation of Hebei Province, China (C2020204039), the Key Research and Development Projects of Hebei Province (20326510D), and the Hebei Province Projects of Overseas Foundation (C20190508).

摘要:

前期研究表明,在玉米大斑病菌中存在9个漆酶样多铜氧化酶,其中漆酶基因StLAC2敲除导致黑色素含量降低,不能产生分生孢子,直接影响侵染能力。为进一步研究漆酶基因家族基因在生物学功能上的差异,本文利用同源重组技术创制StLAC6基因敲除突变体并对其对玉米大斑病菌生长发育、致病、杀菌剂抗性等方面的作用进行研究。结果表明通过同源重组技术成功创制了2株StLAC6基因敲除突变体,分析发现StLAC6基因缺失后对玉米大斑病菌的生长、菌丝形态和侵染能力没有显著影响,而且突变体细胞壁及细胞膜功能均正常。进一步对其超微结构进行分析发现,StLAC6基因敲除突变体菌丝中的过氧化物酶体形态异常,影响了菌丝内脂滴合成,同时敲除突变体中的酚类化合物和黑色素的合成增加。通过比较野生型和突变体的EC50值,发现StLAC6敲除导致病菌对嘧菌环胺、三环唑、吡唑醚菌酯等多种常见杀菌剂的敏感性增加,表明漆酶参与了玉米大斑病菌对杀菌剂的抗性。为了明确漆酶基因家族成员的关系,对StLAC6敲除突变体中其他漆酶基因的表达进行分析,发现StLAC1等多个玉米大斑病菌漆酶基因的表达水平发生了显着变化,说明漆酶基因家族成员间存在功能互补。本文为研究植物病原真菌中漆酶基因家族的功能和相互关系提供了新的见解


Abstract:

Laccases, as a kind of multicopper oxidase, play an important role in pigment synthesis and growth in fungi and are involved in their interactions with host plants.  In Setosphaeria turcica, 9 laccase-like multicopper oxidases have been identified, and StLAC2 is involved in the synthesis of the melanin that accumulates in the cell wall.  The function of another major laccase gene, StLAC6, was studied here.  The knockout of StLAC6 had no effect on the growth, morphology or invasion ability of S. turcica, but the morphology and function of peroxisomes of knockout mutants were abnormal.  The knockout of the StLAC6 gene resulted in increased contents of phenolic compounds and melanin and the sensitivity to fungicides increased compared with wild type strains.  In the mutants of StLAC6, there is a significant change of the expression levels of other laccase genes.  This study provides a new insight into laccase functions and the relationship of the laccase gene family in plant pathogenic fungi.   

Key words: Setosphaeria turcica ,  Laccase , StLAC6 , peroxisome , fungicides