AfldevR正调控黄曲霉生长发育和黄曲霉毒素B_(1)生物合成的研究  

Research on the positive regulation of AfldevR in the growth and development of Aspergillus flavus and biosynthesis of aflatoxin B_(1)

作　　者：刘兴赛 兰海儿 赵风光 魏闪 雷阳[1] 胡元森[1] 吕扬勇[1] LIU Xingsai;LAN Haier;ZHAO Fengguang;WEI Shan;LEI Yang;HU Yuansen;LYU Yangyong(College of Biological Engineering,Henan University of Technology,Zhengzhou 450001,China)

机构地区：[1]河南工业大学生物工程学院,河南郑州450001

出　　处：《河南工业大学学报(自然科学版)》2025年第1期64-74,共11页Journal of Henan University of Technology:Natural Science Edition

基　　金：河南省自然科学基金项目(222300420037)。

摘　　要：深入研究bHLH类型转录因子AfldevR调控黄曲霉生长和黄曲霉毒素B_(1)(AFB_(1))生物合成机理,为防控粮食储藏过程中AFB_(1)污染提供新的潜在靶点。以AfldevR基因缺失及回补菌株为研究对象,通过显微观察表征该基因缺失对黄曲霉生长和产孢的影响;采用层析和高效液相色谱对AFB_(1)含量进行测定,并探究基因缺失对AFB_(1)生物合成途径基因表达水平的影响;采用PI和DAPI荧光染料分别检测黄曲霉细胞膜和细胞核完整性;以花生籽粒和玉米粉为培养基质测定菌株的致病性。结果表明:与对照菌株相比,AfldevR基因缺失显著抑制菌落生长速度和孢子数量,细胞核受到损伤,细胞膜通透性增加;AFB_(1)的生物合成受到抑制,其合成途径中aflR、aflA、aflC和aflE基因的转录水平显著下调;AfldevR基因缺失后对氧化胁迫压力更加敏感,在花生上的AFB_(1)含量显著降低,但在玉米粉上无明显差异。综上,AfldevR基因正调控黄曲霉生长、AFB_(1)合成途径中基因的转录水平、毒素产量以及对氧化胁迫的耐受性。Investigating the regulatory mechanism of bHLH-type transcription factor AfldevR on cell development and aflatoxin B_(1)(AFB_(1))biosynthesis in Aspergillus flavus can provide novel potential targets for preventing and controlling A.flavus growth and AFB_(1)contamination during grain storage.Using AfldevR gene deletion(ΔAfldevR)and complementation strains(ΔAfldevR-com)as research subjects,the effects of AfldevR deletion on colony growth and sporulation of A.flavus were characterized by plate culture,section and stereomicroscopy observation.Thin layer chromatography(TLC)and high-performance liquid chromatography(HPLC)were employed to measure AFB_(1)content.The influence of AfldevR gene deletion on the expression levels of genes involved in AFB_(1)biosynthesis pathway was also explored.PI and DAPI fluorescent dyes were used to detect the integrity of AfldevR cell membrane and nuclei,respectively.The pathogenicity ofΔAfldevR strain was determined using peanut kernel and corn meal as culture substrates.The results indicated that compared with the control strains,AfldevR gene deletion significantly inhibited the growth rate and spore production of A.flavus,damaged the cell nuclei,and increased cell membrane permeability.The amount of AFB_(1)biosynthesis decreased significantly,and the transcriptional levels of aflR,aflA,aflC and aflE were significantly down-regulated.Additionally AfldevR gene deletion strain was more sensitive to oxidative stress,and the growth inhibition rates of the control strain andΔAfldevR strain treated with 20 mmol/L H_(2)O_(2) were 31.09%and 100%,respectively.Compared with wild-type and complementation strains,AFB_(1)yield ofΔAfldevR strain was significantly reduced on peanuts,but showed no significant difference on corn meal.In summary,the AfldevR gene positively regulates the growth of A.flavus,the transcription levels of genes involved in AFB_(1)biosynthesis,AFB_(1)production and tolerance to oxidative stress.This study provides a theoretical support for the development of fungicides t

关 键 词：黄曲霉 黄曲霉毒素B_(1) AfldevR bHLH转录因子 粮食储藏 

分 类 号：TS201.3[轻工技术与工程—食品科学]