Microbial consortia and their metabolic modulations as mechanisms of water deficit tolerance in strawberry plants.

INTRODUCTION

One effective and ecologically sustainable strategy that has emerged to enhance plant resilience to water deficits induced by drought stress is the application of plant growth-promoting microorganisms (PGPM). Despite this progress, there remains a lack of clarity in identifying the most effective microbial consortia and understanding the nutritional and metabolic processes that contribute to the drought resilience of strawberry crops.

METHODS

Two effective microbial consortia were selected based on previous data: CS1 (Claroideoglomus claroideum + Naganishia albida + Paraburkholderia caledonica) and CS2 (Funneliformis mosseae + Candida guillermondii + Bacillus tequilensis) used for drought stress mitigation in plants. These were tested under two irrigation scenarios-well-watered and water-limited conditions, corresponding to 85% and 30% of their water holding capacity (WHC), respectively.

RESULTS

The co-inoculation of the CS1 consortium increased SDW by 38.23% compared to the control and 52.94% compared to CS2. Likewise, this consortium increased the concentrations of N, P, and K by 24.3%, 6.4%, and 25.7%, respectively, compared to the WS control. Finally, CS1 mitigated phytotoxic effects by activating flavonoid-type, fatty acids, and phenolic acid metabolites, as well as growth-regulating hormones, compared to the CS2 consortium and control plants, whose changes in specialized metabolism did not allow them to tolerate stress.

DISCUSSION: This study elucidated the molecular mechanisms by which microbial biostimulants increase drought tolerance.