ABSTRACT
Low-temperature stress can seriously impair plant physiology. Chilling injury leads to a complex array of cellular dysfunctions, and symptoms include chlorosis, sterility, loss of vigor, wilting, and even death of the plants. Furthermore, phosphorus limitations additionally halt the growth of plants. Low-temperature adaptive plant growth-promoting microbes through various direct and indirect mechanisms help in the survival of plants under stress conditions. The present investigation deals with isolation of P-solubilizing psychrotrophic bacteria from diverse cultivars of wheat grown in the Keylong region of Himachal Pradesh. A total of 33 P-solubilizing bacterial isolates were obtained. P-solubilizers were screened for different plant growth-promoting (PGP) attributes of K and Zn solubilization, production of IAA, siderophores, and different hydrolytic enzymes. Among 33 P-solubilizers, 8 efficient strains exhibiting multiple PGP attributes were used as bioinoculants for wheat under low-temperature stress in different in vitro and in vivo experiments. The psychrotrophic bacterial isolates positively influenced the growth and physiological parameters as well as nutrient uptake and yield of wheat and efficiently alleviated low-temperature stress. The potential of low-temperature stress adaptive and PGP microbes can be utilized in agricultural sector for amelioration of low-temperature stress and plant growth promotion. The present study deals with the isolation of psychrotrophic P-solubilizers with multiple PGP attributes and their role in alleviation of cold stress in wheat.