中国农业科学 ›› 2020, Vol. 53 ›› Issue (10): 1986-1996.doi: 10.3864/j.issn.0578-1752.2020.10.006

• 植物保护 • 上一篇    下一篇

水稻根系细菌挥发性有机物对小孢根霉的非接触性抑制作用

王恩召,范分良,李艳玲,刘雄舵,卢玉秋,宋阿琳()   

  1. 中国农业科学院农业资源与农业区划研究所,北京100081
  • 收稿日期:2019-09-27 接受日期:2019-11-07 出版日期:2020-05-16 发布日期:2020-05-22
  • 通讯作者: 宋阿琳
  • 作者简介:王恩召,E-mail:enzhaowang@163.com。
  • 基金资助:
    国家重点研发计划(2016YFD0800707);国家重点研发计划(2016YFD0200109);国家自然科学基金(41571297);中央级公益性科研院所基本科研业务费专项(1610132019011);中央级公益性科研院所基本科研业务费专项(1610132019021)

Noncontact Inhibitory of Volatile Organic Compounds from Rice Root Bacteria on Rhizopus microsporus

WANG EnZhao,FAN FenLiang,LI YanLing,LIU XiongDuo,LU YuQiu,SONG ALin()   

  1. Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081
  • Received:2019-09-27 Accepted:2019-11-07 Online:2020-05-16 Published:2020-05-22
  • Contact: ALin SONG

摘要:

【目的】 通过分析水稻根系细菌挥发性有机物(volatile organic compounds,VOCs)组成和对小孢根霉(Rhizopus microsporus)的抑制作用,寻找新的具有潜在抑菌功能的挥发性物质。【方法】 通过对扣熏蒸法测定不同细菌对小孢根霉的抑菌率;采用顶空固相微萃取法收集细菌挥发性有机物,对其进行气相色谱-质谱(GC-MS)检测,测得细菌挥发性有机物质谱,并在NIST/EPA/NIH数据库中进行比对鉴定,根据抑菌效果及各物质在质谱中的峰面积,进行相关性分析,购买与抑菌率具有显著相关性的物质,体外检测这些纯物质对小孢根霉的抑制作用。【结果】 所有菌株均能释放挥发性有机物,并且通过挥发性有机物的非接触性产生不同的抑菌效果,这些菌株共产生14类90种挥发性有机物,分别为酯、烯烃、烷、酮、酸、噻吩、醛、萘、硫化物、酚、醇、吡嗪、吡咯和苯类物质,其中所有菌株都能够释放醇类物质。通过相关性分析,发现有6种物质具有潜在的抑菌活性,分别为2-庚酮、5-甲基-2-己酮、2-壬酮、5-甲基-3-己酮、3-甲基丁酸和甲基异丁基酮,其释放量与抑菌率呈显著正相关,其中3种(2-庚酮、2-壬酮和甲基异丁基酮)是前期研究已经报道过具有抑菌活性的物质,其余3种物质(5-甲基-2-己酮、5-甲基-3-己酮和3-甲基丁酸)暂未被报道具有抑菌活性,通过购买其中2种物质3-甲基丁酸和5-甲基-2-己酮进行体外熏蒸试验验证,发现3-甲基丁酸严重抑制小孢根霉生长,5-甲基-2-己酮对小孢根霉具有致死作用。5-甲基-2-己酮主要由菌株麦克默多生孢八叠球菌、短短芽孢杆菌和阿氏芽孢杆菌释放,5-甲基-3-己酮主要由菌株假单胞菌、阿氏芽孢杆菌和麦克默多生孢八叠球菌释放,3-甲基丁酸主要由菌株神户肠杆菌、假单胞菌和阿氏芽孢杆菌释放。【结论】 水稻根系细菌能释放种类丰富的挥发性有机物,部分挥发性有机物对水稻病原菌小孢根霉具有显著抑制作用。经过相关性分析及体外验证确定了2种新型的具有抑菌活性的物质(5-甲基-2-己酮和3-甲基丁酸)以及1种可能具有抑菌活性的物质(5-甲基-3-己酮),这些菌株和挥发性有机物均具有作为新型药物和抗真菌代谢物生物资源的潜力。

关键词: 水稻根系, 挥发性有机物, 抑菌效果, 细菌, 小孢根霉, 顶空-固相微萃取-气质联用

Abstract:

【Objective】The objective of this study is to identify new bacterial volatile organic compounds (VOCs) with potential antimicriobial function by analyzing the composition of VOCs of rice root bacteria and their inhibitory effects on Rhizopus microsporus.【Method】The inhibition rate of different bacteria to R. microsporus was determined by a double Petri dish assay. The VOCs of bacteria were collected by headspace-solid phase microextraction and detected by gas chromatography-mass spectrometry (GC-MS). The detected VOCs were compared and identified in the NIST/EPA/NIH database. According to the inhibitory effect and the peak area of each substance in mass spectrum, the correlation analysis was conducted. The VOCs which have a significant correlation with inhibition rate were purchased and the inhibitory effect of these pure substances on R. microsporum was detected in vitro.【Result】All strains could release VOCs and had different inhibitory effects through non-contact of VOCs. These strains produced a total of 90 VOCs of 14 types, which were esters, olefins, alkanes, ketones, acids, thiophenes, aldehydes, naphthalenes, sulfides, phenols, alcohols, pyrazines, pyrroles and benzenes. All strains could release alcohols. Through correlation analysis, 6 VOCs (2-heptanone, 5-methyl-2-hexanone, 2-nonanone, 5-methyl-3-hexanone, 3-methyl-butanoic acid and methyl isobutyl ketone) were found to have potential antimicriobial activity, there was a significant positive correlation between the release amount and inhibition rate. Among them, 3 of these VOCs (2-heptanone, 2-nonanone and methyl isobutyl ketone) had been reported to have antimicriobial activity in previous studies. The other 3 VOCs (5-methyl-2-hexanone, 5-methyl-3-hexanone and 3-methyl-butanoic acid) had not been reported. In vitro fumigation test was conducted by purchasing two of them (3-methyl-butanoic acid and 5-methyl-2-hexanone). It was found that 3-methyl-butanoic acid seriously inhibited the growth of R. microspores, and 5-methyl-2-hexanone was lethal to the R. microspores. Among them, 5-methyl-2-hexanone was mainly released by the strains of Paenisporosarcina macmurdoensis, Brevibacillus brevis and Bacillus aryabhattai. 5-methyl-3-hexanone was mainly produced by the strains of Pseudomonas, B. aryabhattai and P. macmurdoensis. 3-methyl-butanoic acid was mainly released by strains of Enterobacter kobei, Pseudomonas and B. aryabhattai. 【Conclusion】Rice root bacteria can release a variety of VOCs, some of which have a significant inhibitory effect on rice pathogen R. microsporum. Through correlation analysis and in vitro validation, two new antimicriobial VOCs (5-methyl-2-hexanone and 3-methyl-butanoic acid) and one possible antimicriobial VOC (5-methyl-3-hexanone) were identified. All these strains and VOCs have the potential as biological resources for new drugs and antifungal metabolites.

Key words: rice root, volatile organic compounds (VOCs), inhibitory effect, bacteria, Rhizopus microsporus, headspace-solid phase microextraction-mass combination