Mining Halophytes for Plant Growth-Promoting Halotolerant Bacteria to Enhance the Salinity Tolerance of Non-halophytic Crops.

Hassan Etesami,Gwyn A Beattie

doi:10.3389/fmicb.2018.00148

Abstract

Salinity stress is one of the major abiotic stresses limiting crop production in arid and semi-arid regions. Interest is increasing in the application of PGPRs (plant growth promoting rhizobacteria) to ameliorate stresses such as salinity stress in crop production. The identification of salt-tolerant, or halophilic, PGPRs has the potential to promote saline soil-based agriculture. Halophytes are a useful reservoir of halotolerant bacteria with plant growth-promoting capabilities. Here, we review recent studies on the use of halophilic PGPRs to stimulate plant growth and increase the tolerance of non-halophytic crops to salinity. These studies illustrate that halophilic PGPRs from the rhizosphere of halophytic species can be effective bio-inoculants for promoting the production of non-halophytic species in saline soils. These studies support the viability of bioinoculation with halophilic PGPRs as a strategy for the sustainable enhancement of non-halophytic crop growth. The potential of this strategy is discussed within the context of ensuring sustainable food production for a world with an increasing population and continuing climate change. We also explore future research needs for using halotolerant PGPRs under salinity stress.

Highlights

Food security is a fundamental need of all societies
This review has highlighted the potential for halophytes to be used as an isolation source for halotolerant PGPRs, including PGPRs that exhibit plant growth-promoting (PGP) traits such as IAA production, phosphate solubilization, siderophore production, N2 fixation, ACC deaminase activity, and control of phytopathogens
Halotolerant PGPRs isolated from the endosphere or rhizosphere of halophytes can be used to enhance the growth, and possibly the yield, of halophytic and non-halophytic crops (Sáenz-Mata et al, 2016)

Summary

Introduction

Food security is a fundamental need of all societies. The global population is projected to increase to around 10 billion people within the 50 years (Godfray et al, 2010). Plants inoculated with ACC deaminase-producing PGPRs often exhibit extended root growth, attributed to reductions in ethylene, and enhanced resistance to salinity stress (Mayak et al, 2004a,b; Cheng et al, 2007; Glick et al, 2007; Zahir et al, 2009; Nadeem et al, 2010; Barnawal et al, 2012; Jha et al, 2012; Etesami and Beattie, 2017).

Results

Conclusion