Introducing silica-solubilizing and plant growth-promoting bacteria from sugarcane as inducers of drought stress...

Today’s sugarcane cultivation is faced with abiotic stresses including drought, salinity, heat and water limitation leading to, its reduced growth, yield, and economic productivity. Given the significant role of silica in alleviating these negative effects as well as pathogens, silica solubilizing bacteria opens an eco-friendly and sustainable approach to overcome these challenges. The aim was to find native silicate solubilizing bacteria from sugarcane and assessment their plant growth-promoting potential. Extensive screening was done from five sugarcane fields and symbiont bacterial species were qualitatively and quantitatively selected with regard to silicate solubilization. The isolates were explored for plant growth-promoting traits. As a result, Pantoea ananatis ASEna, Pantoea dispersa E345Se, and Pseudomonas migulae DSb were identified as high silica solubilizers. These also exhibited antifungal activity; phosphorus and potassium solubilization; sulfur oxidation; protease and cellulose production; auxin, hydrogen cyanide, and ammonia synthesis; nitrogen fixation; tolerance to heat, salinity (10%), drought, and pH stresses. The identified genera are part of the core sugarcane microbiome, and this is for the first time that these species have been documented as possessing growth-promoting traits for sugarcane and silicate-solubilizing capabilities. Currently, sugarcane producers are seeking for solutions to mitigate biotic and abiotic stresses and enhance crop yield in sugarcane fields. The strategic selection of bacteria that not only solubilize silica but also possess growth-promoting traits and can supply other essential nutrients to stimulating plant growth through various mechanisms, can enhance the effectiveness of silicate-solubilizing bacteria and make them suitable candidates for development of biofertilizers.