P lant–Microbe Interaction and Salt Stress Tolerance in Plants

Talaat, N. B., "P lant–Microbe Interaction and Salt Stress Tolerance in Plants", Managing Salt Tolerance in Plants: Molecular and Genomic Perspectives, USA, Taylor & Francis Group, 2015.


Excessive salt accumulation in soils is a major ecological and agronomical problem, in particular in arid and semiarid areas. While important physiological insights about the mechanisms of salt tolerance in plants have been gained, the transfer of such knowledge into crop improvement has been limited. The identification and exploitation of soil microorganisms (especially rhizosphere bacteria and mycorrhizal fungi) that interact with plants by alleviating stress opens new alternatives for a pyramiding strategy against salinity as well as
new approaches to discover new mechanisms involved in stress tolerance. Considering the kingdom of fungi, arbuscular mycorrhizal fungi (AMF) stand out as the most significant and widespread group of plant growth–promoting microorganisms. Ectomycorrhizal fungi (EMF) are also important symbionts of particular relevance for many woody plants. Considering the kingdom of bacteria, a wide range of microorganisms including different species and strains of Bacillus, Burkholderia, Pseudomonas, and the well-known nitrogen-fixing organisms
Rhizobium, Bradyrhizobium, Azotobacter, Azospirillum,
and Herbaspirillum are classically regarded as
important plant growth–promoting rhizobacteria
(PGPR). Today, it is widely accepted that
AMF, EMF, and PGPR promote plant growth and
increase tolerance against stress conditions, at
least in part, because they facilitate water and
nutrient uptake and distribution as well as alter
plant hormonal status, and this ability has been
attributed to various mechanisms. This chapter
addresses the significance of soil biota in alleviation
of salinity stress and their beneficial effects
on plant growth and productivity. Moreover,
it emphasizes new perspectives and challenges
in physiological and molecular studies on salt
stress alleviation by soil biota.