生物技术通报2024，Vol.40Issue(11)：277-284,8.DOI:10.13560/j.cnki.biotech.bull.1985.2024-0388
基因envZ、iscS、asnC调控根瘤菌胞外多糖产量和环境适应性
Exopolysaccharide Yield and Environmental Adaptation of Rhizobia Regulated by Gene envZ,iscS and asnC
摘要
Abstract
[Objective]Rhizobium yanglingense CCBAU 01603 form efficient nitrogen-fixing nodules with Caragana legumes.Alk_40,one of the offspring of CCBAU 01603,was obtained through experimental evolution in alkaline medium for 500 generations.It was discovered that a significant decrease in exopolysaccharide(EPS)yields of Alk_40 with specific SNPs changes in the gene envZ,iscS,and asnC.EPS yields and environmental adaptability of rhizobia regulated by these key genes were investigated.[Method]Three mutants of rhizobia were created by deleting gene envZ,iscS,and asnC,respectively.EPS yields and growth under different environmental conditions of mutants were assessed.[Result]In comparison to CCBAU 01603,the envZ,iscS,and asnC mutants presented significantly lower EPS yields in YMA medium,demonstrated diminished fitness in acidic environments,and had a weakened tolerance to high temperatures of 65℃.This observation suggests a correlation between the EPS yield of rhizobia and their resistances to acidic or heat stress.In addition,the mutants lacking the envZ and asnC genes showed the sensitivity to NaCl,resulting in severely limited growth and reproduction in NaCl-containing media.Furthermore,their adaption in alkalescent environments significantly reduced as well.[Conclusion]It is discovered that EPS yields of rhizobia can be regulated by gene envZ,iscS,and asnC.关键词
根瘤菌/envZ/iscS/asnC/胞外多糖/环境适应性Key words
Rhizobium/envZ/iscS/asnC/exopolysaccharide/environmental adaptation引用本文复制引用
杨冰洁,袁晓霞,高梦哲,申奥龙,李华,冀照君..基因envZ、iscS、asnC调控根瘤菌胞外多糖产量和环境适应性[J].生物技术通报,2024,40(11):277-284,8.基金项目
国家自然科学基金项目(32170020,31860001),内蒙古自治区科技计划项目(2021GG0005),中央引导地方科技发展资金项目(2022ZY0158),内蒙古自治区自然科学基金项目(2024JQ12,2022QN03030,2023MS03053) （32170020,31860001）
