Alleviation of cold stress in wheat seedlings by Bacillus amyloliquefaciens IARI-HHS2-30, an endophytic psychrotolerant K-solubilizing bacterium from NW Indian Himalayas.

Abstract

Forty one endophytic bacteria were isolated from surface-sterilized roots and culms of wheat var. HS507, growing in NW Indian Himalayas. These bacteria were screened in vitro for multifarious plant growth promoting attributes such as solubilization of phosphorus, potassium, zinc; production of indole acetic acids, hydrogen cyanide, gibberellic acid, siderophore and activities of nitrogen fixation, ACC deaminase and biocontrol against Rhizoctonia solani and Macrophomina phaseolina at low temperature (4 °C). One isolate IARI-HHS2-30, showed appreciable level of potassium solubilization was further characterized in vivo at control condition of low temperature. Based on 16S rDNA sequence analysis, this isolate was identified as Bacillus amyloliquefaciens assigned accession number KF054757. Analysis of the phylogenetic characterization showed close homology with typical psychrotolerant bacteria Bacillus amyloliquefaciens, Bacillus methylotrophicus, Bacillus polyfermenticus, Bacillus siamensis, Bacillus subtilis, and Bacillus vallismortis. Endophytic nature and plant growth promoting ability of IARI-HHS2-30 was tested by qualitatively and followed by inoculation onto wheat seedlings in low temperature conditions. At 30 days after inoculation, Bacillus amyloliquefaciens IARI-HHS2-30 to wheat plants resulted in significant increase in root/shoot length, fresh weight, and chlorophyll a content. Plant growth promoting features coupled with psychrophilic ability suggest that this endophytic bacterium may be exploited as bio-inoculants for various crops in low temperature and high altitude condition