Bharti Nidhi, Barnawal Deepti, Maji Deepamala, Kalra Alok
Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow, 226015, India.
Microb Ecol. 2015 Jul;70(1):196-208. doi: 10.1007/s00248-014-0557-4. Epub 2014 Dec 28.
The resilience of soil microbial populations and processes to environmental perturbation is of increasing interest as alteration in rhizosphere microbial community dynamics impacts the combined functions of plant-microbe interactions. The present study was conducted to investigate the effect of inoculation with halotolerant rhizobacteria Bacillus pumilus (STR2), Halomonas desiderata (STR8), and Exiguobacterium oxidotolerans (STR36) on the indigenous root-associated microbial (bacterial and fungal) communities in maize under non-saline and salinity stress. Plants inoculated with halotolerant rhizobacteria recorded improved growth as illustrated by significantly higher shoot and root dry weight and elongation in comparison to un-inoculated control plants under both non-saline and saline conditions. Additive main effect and multiplicative interaction ordination analysis revealed that plant growth promoting rhizobacteria (PGPR) inoculations as well as salinity are major drivers of microbial community shift in maize rhizosphere. Salinity negatively impacts microbial community as analysed through diversity indices; among the PGPR-inoculated plants, STR2-inoculated plants recorded higher values of diversity indices. As observed in the terminal-restriction fragment length polymorphism analysis, the inoculation of halotolerant rhizobacteria prevents major shift of the microbial community structure, thus enhancing the resilience capacity of the microbial communities.
随着根际微生物群落动态变化影响植物 - 微生物相互作用的综合功能，土壤微生物种群和过程对环境扰动的恢复力越来越受到关注。本研究旨在调查接种耐盐根际细菌短小芽孢杆菌（STR2）、嗜盐嗜碱菌（STR8）和耐氧化嗜微杆菌（STR36）对非盐胁迫和盐胁迫下玉米原生根系相关微生物（细菌和真菌）群落的影响。与未接种的对照植物相比，接种耐盐根际细菌的植物在非盐和盐胁迫条件下均表现出更好的生长，如地上部和根部干重显著增加以及伸长。加性主效应和乘性交互作用排序分析表明，植物生长促进根际细菌（PGPR）接种以及盐度是玉米根际微生物群落变化的主要驱动因素。通过多样性指数分析，盐度对微生物群落有负面影响；在接种PGPR的植物中，接种STR2的植物多样性指数值更高。如末端限制性片段长度多态性分析所示，接种耐盐根际细菌可防止微生物群落结构的重大变化，从而增强微生物群落的恢复能力。
