Bioprospecting Cold-Adapted Indole Acetic Acid-Producing Bacteria With Multifaceted Plant Growth Promoting Traits for...

Agriculture in high altitude regions is challenged by low temperatures, and the use of chemical fertilizers turned hazardous in the long run. In addition, cost-effective, eco-friendly biofertilizers developed globally are less effective in cold regions due to temperature-sensitive mesophilic homologs. The current study evaluated the potential of a cold-adapted indole acetic acid (IAA)-producing bacterial consortium isolated from Ghulkin glacier, Hunza Valley, Pakistan, to promote the growth of the crop, wheat, under cold stress. Several IAA-producing bacteria were isolated and tested further for siderophore production, zinc-solubilizing activity, phosphate solubilizing activity, ability to utilize 1-aminocyclopropane-1-carboxylate and for nitrogen fixation. A microbial consortium was constructed and evaluated for its effectiveness in promoting wheat growth in pot experiments under ambient conditions (2°C-6°C at nighttime and 15°C-20°C at daytime) and with diverse soil and glacial flour matrices. The cold-adapted bacteria showed positive plant growth promoting attributes and with remarkable positive impacts on root length, shoot length, root and shoot fresh, and dry weight in pot trials in both garden soil and the glacial flour. An increase in wheat plant chlorophyll content was also observed in both pot experiments of glacial flour and garden soil. It was concluded that a multistrain bacterial consortium of Nocardiooides zeae GB3, Arthrobacter flavus GA9, and Pseudomonas sp. GB29 may have potential as an efficient biofertilizer for promoting mountainous crops, in the Gilgit Baltistan region, Pakistan.