Synergistic association of endophytic fungi enhances Glycine max L. resilience to combined abiotic stresses: Heavy metals, high temperature and drought stress

Recently, the use of endophytic fungi for promoting growth and alleviating abiotic stress has gained considerable attention. However, the association of compatible endophytic fungi with crop plants under simultaneous effects of abiotic stresses is less explored. The current study elucidated the interactive effects of hormone (gibberellins and indole-3-acetic acid)-producing and combined multi-abiotic stresses (heavy metals; Ni, Cd, and Al, drought resistant, high temperature) resistant Paecilomyces formosus LHL10 and Penicillium funiculosum LHLO6 on Glycine max L. under heavy metals (NI, Cd, and Al), high temperature and drought (HID) stress. Results revealed that the co-inoculation of LHL10 and LHLO6 promoted plant growth attributes and photosynthetic activity as well as glutathione, catalase, and SOD activities and decreased lipid peroxidation by enhancing macronutrient uptake under HTD stress. Additionally, the co-inoculation reduced metal accumulation and translocation in plants by down-regulating heavy metal ATPase gene (GmHMA13, GmHMA14, and GmliMA18) expression. Furthermore, the regulation of drought-related GmDREB2, GmDREBIB, GmERD1, GmRD20, and heat shock protein 90 (GmHsp90A2 and GmHsp90A1) gene expression in co-inoculated plants reduced endogenous abscisic acid and jasmonic acid levels and positively affected plant development under HTD stress. The duo of LHL10 and LH1,06 proved to be a vital strategy for the development of G. max in metal-contaminated soil in semiarid and high-temperature conditions for sustainable agriculture.