Endophytic fungus Phomopsis liquidambari and different doses of N-fertilizer alter microbial community structure and function in rhizosphere of rice.

Md. Ashaduzzaman Siddikee,Cai-Feng Li,Chuan-Chao Dai,Mst Israt Zereen

doi:10.1038/srep32270

Md. Ashaduzzaman Siddikee, Cai-Feng Li + Show 2 more

Open Access

https://doi.org/10.1038/srep32270

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Journal: Scientific Reports	Publication Date: Sep 6, 2016
Citations: 31	License type: CC BY 4.0

Affiliation: Nanjing Normal University

Abstract

Microbial community structure and functions of rhizosphere soil of rice were investigated after applying low and high doses of nitrogenous fertilizer and Phomopsis liquidambari. Average well color development, substrate richness, catabolic diversity and soil enzymes activities varied after applying N-fertilizer and P. liquidambari and were greater in P. liquidambari treated soil than only N-fertilization. Multivariate analysis distinctly separated the catabolic and enzymes activity profile which statistically proved alteration of microbial functional diversity. Nitrogen fertilizer altered microbial community structure revealed by the increased content of total PLFAs, specific subgroup marker PLFAs except fungal PLFAs and by the decreased ratio of G+/G−, sat/monunsat, iso/anteiso, F/B except trans/cis while P. liquidambari inoculation enhanced N-fertilization effect except increased fungal PLFA and decreased trans/cis. PCA using identified marker PLFAs revealed definite discrimination among the treatments which further statistically confirmed structural changed of microbial community. Nitrogenase activity representative of N-fixing community decreased in N-fertilizer treatment while P. liquidambari inoculation increased. In short, application of P. liquidambari with low doses of N-fertilizer improved rice growth and reduced N-fertilizer requirement by increasing enzymes activities involved in C, N and P cycling, structural and functional diversity of microbes, nitrogenase activity involved in N2 fixation and accumulation of total-N.

Highlights

Community involved in N-turnover[3,16,17] and by affecting microbial abundance of AOA, AOB and diazotrophs[3]
Average well color development (AWCD) generally followed sigmoidal pattern with incubation time, but the rate of increase varied with different level of N-fertilizer application and P. liquidambari inoculation which indicating microbial composition and metabolic activity differ among treatment (Supplementary Table S1; Supplementary Fig. S1a,b)
Utilization of carbohydrate, carboxylic acids and polymer-esters was highest in P. liquidambari and low doses of N-fertilizer treated soil whereas lowest in soil treated with high doses of N-fertilizer irrespective of P. liquidambari inoculation (Fig. 1)

Summary

Introduction

Community involved in N-turnover[3,16,17] and by affecting microbial abundance of AOA, AOB and diazotrophs[3]. We attempted to get the clear picture about the effect of application of N-fertilizer with or without P. liquidambari on whole community structure, functional diversity, extra-cellular enzymes activity, N-fixation efficiency and growth of rice plant. We used EcoPlate to compare potential metabolic shift and diversity of microbial communities of rhizospheric soil of rice after applying different doses of N-fertilizer with or without P. liquidambari. We used PLFA technique to study the changes in specific PLFA markers representative of specific microbial groups to describe influence of different doses of N-fertilizer and P. liquidambari on community structure of rhizosphere soil of rice. The aim of this study was to determine the effects of different doses of N-fertilizer with or without P. liquidambari inoculation on (i) microbial community structure, function and extracellular enzyme activities, (ii) N2 fixation, nitrogenase enzyme activity and N-fixing community and (iii) growth promotion of rice

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