Salt Stress Alleviation Potential of Endophytic Fungi on Okra Plant Growth

Abstract

Saline environments for plants have a negative impact on their biochemical, molecular, and physiological features, resulting in a loss in plant growth and yield in most parts of the world. Hormonal imbalance, ionic toxicity, ROS production, impaired nutrient mobilization, and osmotic stress all contribute to plant growth loss. The symbiotic connection of several endophytes with their host plants has improved plant tolerance to various abiotic challenges in recent years. So, the current study aimed to see how Aspergillus japonicus and salinity affected growth parameters, plant biochemistry, antioxidant enzyme status, endogenous IAA, and various anion and cation concentrations in okra. According to the findings, applying salt lowered numerous growth properties, including Chlorophyll a and b, total chlorophyll, and endogenous IAA. Enhanced values of a/b (chlorophyll), total carotenoids, total proteins, total carbs, total lipids, total proline, total phenol, total flavonoids, total tannin, lipid peroxidation, catalase, and ascorbate peroxidase were seen at similar salt levels. In okra (Sanaf green), salt application resulted in salt accumulation and higher levels of Cl, Na, Ca/K, and Na/K ratio, while low contents of K, P, Mg, Ca, O, N, and C were found. The results of this study show that using Aspergillus japonicus promotes plant resistance to saltwater environments, as evidenced by the fact that using the fungal strain increased the values of many growth parameters, metabolites, anti-oxidant enzyme activity, and endogenous IAA. In the same way, using Aspergillus japonicus lowered the amount of lipid peroxidation in the okra plant. The accumulation of salts in okra after application of Aspergillus japonicus resulted in an increase in Ca, Mg, N, C, K, Cl, O, and P values, as well as a decrease in the Ca/K and Na/K ratios, Cl, and Na values. According to the findings, salt stress causes stunted development and altered biochemistry in okra, while the presence of Aspergillus japonicus aids in plant salt tolerance. As a result, this strain is an excellent candidate for testing as a biostimulant/biofertilizer to improve the growth of essential crops in Pakistan's salt-affected areas.