Dual SA-mediated and SA-independent mechanisms drive <i>Sphingomonas paucimobilis</i> -induced cold tolerance in <i>Arabidopsis</i>

S. paucimobilis ZJSH1 exhibits intrinsic cold tolerance with both SA-dependent and SA-independent mechanisms contributing to its adaptation to low temperatures. While SA plays a critical role in enhancing osmolyte accumulation, antioxidant activity, and membrane stabilization, the SA-deficient ΔpchB mutant activates alternative metabolic pathways. These findings suggest that ZJSH1 may be useful in improving plant stress tolerance under cold stress conditions.