Identifying potential molecular factors involved in <i>Bacillus amyloliquefaciens</i> 5113 mediated abiotic stress tolerance in wheat

Abstract

Abiotic stressors are main limiting factors for agricultural production around the world. Plant growth-promoting bacteria have been successfully used to improve abiotic stress tolerance in several crops including wheat. However, the molecular changes involved in the improvement of stress management are poorly understood. The present investigation addressed some molecular factors involved in bacterially induced plant abiotic stress responses by identifying differentially expressed genes in wheat (Triticum aestivum) seedlings treated with the beneficial bacterium Bacillus amyloliquefaciens subsp. plantarum UCMB5113 prior to challenge with abiotic stress conditions such as heat, cold or drought. cDNA-AFLP analysis revealed differential expression of more than 200 transcript-derived fragments (TDFs) in wheat leaves. Expression of selected TDFs was confirmed using RT-PCR. DNA sequencing of 31 differentially expressed TDFs revealed significant homology with both known and unknown genes in database searches. Virus-induced gene silencing of two abscisic acid-related TDFs showed different effects upon heat and drought stress. We conclude that treatment with B. amyloliquefaciens 5113 caused molecular modifications in wheat in order to induce tolerance against heat, cold and drought stress. Bacillus treatment provides systemic effects that involve metabolic and regulatory functions supporting both growth and stress management.