Potential of kaempferol and caffeic acid to mitigate salinity stress and improving potato growth.

Salinity stress adversely affects plant growth by disrupting water uptake, inducing ion toxicity, initiating osmotic stress, impairing growth, leaf scorching, and reducing crop yield. To mitigate this issue, the application of kaempferol (KP), caffeic acid (CA), and plant growth-promoting rhizobacteria (PGPR) emerges as a promising technology. Kaempferol, a flavonoid, protects plants from oxidative stress, while caffeic acid, a plant-derived compound, promotes growth by regulating physiological processes. PGPR enhances plant health and productivity through growth promotion, nutrient uptake, and stress mitigation, providing a sustainable solution. However, combining these compounds against drought requires further scientific justification. That's why the current study was conducted using 4 treatments, i.e., 0, 20 µM KP, 30 μM CA, and 20 µM KP + 30 μM CA without and with PGPR (Bacillus altitudinis). There were 4 replications following a completely randomized design. Results showed that 20 µM KP + 30 μM CA with PGPR caused significant enhancement in potato stem length (14.32%), shoot root, and leaf dry weight (16.52%, 11.04%, 67.23%), than the control. The enrichment in potato chlorophyll a, b, and total (31.86%, 46.05%, and 35.52%) was observed over the control, validating the potential of 20 µM KP + 30 μM CA + PGPR. Enhancement in shoot N, P, K, and Ca concentration validated the effective functioning of 20 µM KP + 30 μM CA with PGPR evaluated to control. In conclusion, 20 µM KP + 30 μM CA with PGPR is the recommended amendment to alleviate salinity stress in potatoes.