Alleviation potential of endophytic fungus Aspergillus terreus on growth of okra plantsunder salt stress

Abstract

Soil salinization is a result of climate change and is seen as a growth limiting factor, resulting in lower agricultural yields. Endophytes (bacteria and fungi) are a type of endo-symbiotic microbe that colonizes the intercellular gaps of plant compartments without causing illness to the host plant. Endophytes work together to improve plant development and yield, as well as provide tolerance to host plants against various biotic and abiotic stresses. Therefore, we evaluated the effect of salinity in combination with Aspergillus terreus treatment on anion and cation concentrations, antioxidant enzyme status, growth parameters, endogenous IAA, and plant biochemistry in okra in the current experimental design. Salt application lowered numerous growth parameters, including Chlorophyll a and b, total chlorophyll, and endogenous IAA, according to the findings. Furthermore, increased values of total phenol, ascorbate peroxidase, total carbs, total lipids, catalase, total tannin, a/b (chlorophyll), total flavonoids, lipid peroxidation, total carotenoids, total proteins, and total proline were observed across similar salt levels. When salt is applied to the soil, it causes salt accumulation and increased levels of Ca/K, Na/K, Na, and Cl, while okra has low levels of Mg, Ca, K, P, O, N, and C. The current findings imply that Aspergillus terreus application improves plant tolerance to saline environments, as seen by increased metabolites, antioxidant enzyme activity, endogenous IAA, values of various growth parameters. Likewise, strain treatment suppressed lipid peroxidation in okra. Salt stress in plants inoculated with Aspergillus terreus led to more K, P, O, Mg, N, Ca, Cl, and C with less Ca/K and Na/K and reduced Cl and Na levels. According to the findings, Aspergillus terreus reduces the negative effects of salt on various okra parameters and increases its tolerance to salinity. As a result of its positive action, this strain may be recommended as a biofertilizer in agricultural fields for crop development in Pakistan's salt-contaminated areas.