摘要
【背景】低温是影响北方温室番茄稳产与高产的主要障碍因子,前期研究明确链霉菌(Streptomyces sp.)TOR3209能显著提高番茄的耐低温能力。【目的】揭示菌株TOR3209提高番茄抗冷性与番茄内生细菌结构和特性的关系。【方法】在番茄根部施用TOR3209菌剂,分别在低温(5℃)和常温(25℃)条件下,采用平板分离法和16S rRNA基因序列扩增研究菌株TOR3209处理对番茄根系和茎部内生细菌菌群结构的影响。【结果】共分离、纯化获得内生细菌69株,分属4门20科28属。分析发现,与对照相比,在低温和常温下,接种菌株TOR3209均可提高番茄根茎内生细菌群落的丰富度和多样性。在门水平上,番茄根茎厚壁菌门的相对丰度显著提高,变形菌门和拟杆菌门的相对丰度显著降低;在属水平上,芽孢杆菌属的相对丰度显著提高,假单胞菌属和黄杆菌属的相对丰度则显著降低;在种水平上,菌株TOR3209处理能显著提高番茄根茎解淀粉芽孢杆菌(Bacillus amyloliquefaciens)、贝莱斯芽孢杆菌(Bacillus velezensis)和阿氏芽孢杆菌(Bacillus aryabhattai)等共有芽孢杆菌的相对丰度。常温和低温条件下,TOR3209处理的番茄植株中均分离出威兹曼芽孢杆菌(Bacillus wiedmannii)、耐寒短杆菌(Brevibacterium frigoritolerans)和约氏不动杆菌(Acinetobacter johnsonii),实验证明这3株菌具有促进番茄生长和提高其耐冷的功能,均可显著提高番茄植株的株高、叶面积和生物量,其中耐寒短杆菌提高番茄植株生物量作用效果最为明显,与对照相比,地下部与地上部的鲜重分别提高55.13%和51.03%,干重分别提高48.37%和50.95%。未分离出冰核细菌成团泛菌(Pantoea agglomerans)、地中海假单胞菌(Pseudomonas mediterranea)和皱纹假单胞菌(Pseudomonas corrugate)等条件致病菌。【结论】菌株TOR3209介导番茄根际后优化了番茄内生细菌的菌群结构,耐冷促生等功能菌增多,条件致病菌减少,对提高番茄耐低温能力起到了重要作用。
[Background]Low temperature is the main obstacle factor affecting the stable and high yield of tomato in solar-energy greenhouse in northern China.We found that Streptomyces sp.TOR3209 improved the cold tolerance of tomato plants.[Objective]To explore whether the impact of strain TOR3209 on improving resistance to cold stress of tomato plants is related to their endophytic bacterial community structure and property.[Methods]Tomato roots were inoculated with strain TOR3209 in substrate culture,and cultured under low temperature(5℃)and mild temperature(25℃)separately.Traditional culture-dependent methods were used to isolate and identify bacteria,and the effects of strain TOR3209 on the composition and structure of the root and stem bacterial community were analyzed by 16S rRNA gene amplicon sequencing technology.[Results]In this study,69 species of endophytic bacteria belonging to 28 genera,20 families and 4 phyla were isolated.Compared to the conditions in the control group,the Shannon index and Margalef index of the endophytic bacterial community of tomato roots and stems inoculated with strain TOR3209were increased under low and mild temperatures.At phylum level,the relative abundance of Firmicutes was increased,while that of Proteobacteria and Bacteriodetes was decreased;at genus level,the relative abundance of Bacillus was boosted,while that of Pseudomonas and Flavobacterium was reduced;at species level,after treatment with strain TOR3209,the relative abundance of Bacillus amyloliquefaciens,Bacillus velezensis,and Bacillus aryabhattai was elevated significantly.Under both temperatures of 5℃and 25℃,Bacillus wiedmannii,Brevibacterium frigoritolerans and Acinetobacter johnsonii were isolated from the tomato plants inoculated with strain TOR3209,and the experiment demonstrated that the three bacteria are plant-beneficial and cold-adapted,and can markedly increase the heights,leaf areas and biomasses of tomato plants;especially B.frigoritolerans treatment had the most obvious effect on the biomass.Compared with the conditions in the control group,fresh weight of root and shoot rose by 55.13%and 51.03%,respectively,and dry weight rose by 48.37%and 50.95%,respectively.The pathogenic bacteria such as Pantoea agglomerans,Pseudomonas mediterranea and Pseudomonas corrugate were not isolated.[Conclusion]Inoculation with strain TOR3209 impacted the composition and structure of the bacterial community in tomato roots and stems.The relative abundance of indigenous cold-adapted and beneficial microorganisms was increased,and the pathogenic bacteria was decreased,which improved plant cold tolerance.
作者
马佳
胡栋
彭杰丽
张翠绵
贾楠
王旭
王一凡
王占武
MA Jia;HU Dong;PENG Jieli;ZHANG Cuimian;JIA Nan;WANG Xu;WANG Yifan;WANG Zhanwu(Institute of Agricultural Resources and Environment,Hebei Academy of Agriculture and Forestry Sciences,Hebei Fertilizer Technology Innovation Center,Shijiazhuang 050051,Hebei,China)
出处
《微生物学通报》
CAS
CSCD
北大核心
2023年第1期194-217,共24页
Microbiology China
基金
河北省自然科学基金(C2020301047)
河北省重点研发计划(19222902D)
国家重点研发计划(2021YFD19009)。
关键词
低温胁迫
链霉菌
番茄内生细菌
群落结构
多样性
cold stress
Streptomyces
tomato endophytic bacteria
community structure
diversity