摘要
【背景】由人参链格孢(Alternaria panax)引起的人参黑斑病是人参生产中重要病害之一,在我国长白山和其他人参产区均有发生,给人参生产带来较大损失。【目的】明确过氧化氢酶-过氧化物酶编码基因ApKatG1对人参链格孢生长发育、外界环境胁迫及致病性的影响。【方法】采用同源重组的方法获得人参链格孢中ApKatG1的基因缺失突变体及回补突变体,分析基因缺失突变体在不同培养条件下生长速率、产孢量、对不同胁迫因子的响应及致病性等方面的影响,明确该基因的功能。【结果】ApKatG1基因具有2个典型的过氧化物酶(peroxidase)结构域。基因缺失突变体ΔApkatG1生长速率、产孢量和对碳源的吸收和利用与野生型菌株基本一致,对高渗胁迫因子山梨醇、细胞壁胁迫因子刚果红的敏感性增加,原生质体释放速率加快,并且对高浓度的H_(2)O_(2)敏感性显著增加;H_(2)O_(2)处理后,ApKatG1基因表达水平显著上升;同时ApKatG1基因的缺失影响其他过氧化氢酶(catalase, CAT)基因的表达;ApKatG1基因不影响菌株对人参的致病性。【结论】ApKatG1基因在人参链格孢细胞壁完整性、H_(2)O_(2)胁迫条件的响应中起到重要作用。
[Background]Ginseng Alternaria leaf and stem blight caused by Alternaria panax is one of the major diseases in ginseng production.It mainly occurs in Changbai Mountain and other ginseng-growing areas in China,causing severe losses to ginseng production.[Objective]To clarify the biological functions of the catalase-peroxidase gene ApKatG1 in A.panax.[Methods]The ApKatG1 knockout mutant and complemented mutant were obtained by homologous recombination.The effects of ApKatG1 on the growth rate,sporulation,responses to different stress factors,and pathogenicity were analyzed to elucidate the roles of ApKatG1 in A.panax.[Results]ApKatG1 encoded a catalase-peroxidase containing two typical peroxidase domains.The knockout mutant ΔApkatG1 exhibited the mycelial growth rate,conidiation level,and carbon utilization efficiency comparable to the wild type.However,ΔApkatG1 demonstrated enhanced sensitivity to environmental stress factors such as sorbitol and the cell wall stress factor Congo red,accelerated protoplast release,and significantly increased sensitivity to high concentrations of H_(2)O_(2).The expression level of ApKatG1 significantly increased after H_(2)O_(2) treatment.The knockout of ApKatG1 affected the expression of other catalase genes in A.panax.ApKatG1 did not participate in regulating the pathogenicity of A.panax in ginseng.[Conclusion]ApKatG1 plays a vital role in maintaining cell wall integrity and responding to H_(2)O_(2) stress in A.panax.
作者
兰金玲
杜莹雪
迟美丽
陈长卿
赫荣琳
高洁
LAN Jinling;DU Yingxue;CHI Meili;CHEN Changqing;HE Ronglin;GAO Jie(College of Plant Protection,Jilin Agricultural University,Changchun 130118,Jilin,China;National Ginseng Products Quality Inspection Testing Center,Yanbian 133000,Jilin,China)
出处
《微生物学通报》
北大核心
2025年第12期5793-5809,共17页
Microbiology China
基金
吉林省科技发展计划(20220202110NC)。
