Effects of Bacillus subtilis HS5B5 on Maize Seed Germination and Seedling Growth under NaCl Stress Conditions

Abstract

Salinity is one of the most important factors limiting agricultural productivity. The positive effects of an inoculation with Bacillus subtilis HS5B5 on maize (Zea mays L.) seed germination and seedling growth under saline conditions were elucidated in this study. Maize plants were treated with four NaCl concentrations (0, 100, 200, and 300 mmol·L−1) under hydroponic conditions and the plants inoculated with B. subtilis HS5B5 were compared with the non-inoculated plants in terms of key morphophysiological leaf and root traits. Maize seed germination and seedling growth were inhibited by NaCl stress. The inoculation with B. subtilis HS5B5 significantly increased the germination rate, germination potential, shoot length, and root length under NaCl stress conditions. Moreover, the plant height, biomass, root to shoot weight ratio, above-ground fresh weight, and below-ground fresh weight were higher for the inoculated maize seedlings than for the non-inoculated plants under saline conditions. Additionally, B. subtilis HS5B5 alleviated the salt-induced damage to maize by increasing the chlorophyll content, altering the abundance of osmoregulatory substances, and increasing antioxidant enzyme activities, while decreasing the malondialdehyde content. After the NaCl treatment, the Na+ content in the leaves and roots of maize plants inoculated with B. subtilis HS5B5 decreased significantly, while the K+ content increased. Thus, the inhibitory effect of NaCl stress on maize seed germination and seedling growth was mitigated by B. subtilis HS5B5, suggesting the utility of this microorganism for improving crop cultivation under saline conditions.

Biosynthesis of copper nanoparticles using Solenostemma argel and their effect on enhancing salt tolerance in barley plants

“…Salinity stress is a significant environmental challenge that adversely affects agricultural productivity especially in arid and semiarid regions of the world 1 . Salt stress affects approximately 50% of irrigated land and about 20% of global cropland, leading to a severe reduction in crop growth and yield 2 , 3 . Salinity have led to alterations in various physiological responses in plants like harming the integrity of the plasma membrane, disrupting stomatal conductivity, hinders gaseous exchange and reducing photosynthetic efficiency 4 , 5 .…”

Effect of Nano-zinc Oxide on Rapeseed Growth

“…Low concentrations of nano-metal oxides promote plant seed germination and plant growth [2][3][4] , while high concentrations inhibit plant growth [5] . High concentration of nano-zinc oxide will inhibit the growth of cherry radish [6] , Chinese cabbage seeds [6], mung bean sprouts [7] , asparagus mosaic [8] and corn [9] . Nano-zinc oxide inhibits the elongation of soybean roots and buds, reduces root surface area and root volume, and has a stronger inhibitory effect at high concentrations [10] .…”

Selected Beneficial Microbes Alleviate Salinity Stress in Hydroponic Lettuce and Pak Choi

“…Bacillus and Pseudomonas are beneficial bacteria that help alleviate stress related to high salinity by facilitating nutrient cycling and promoting plant root growth by producing/synthesizing beneficial organic molecules such as abscisic acid or salicylic acid (Kim et al 2017;Yasmin et al 2020). Bacillus species have shown the ability to alleviate salt stress in cucumber (Cucumis sativus) and maize (Zea mays) seedlings (Kaloterakis et al 2021;Song et al 2023), Bacillus has also been shown to improve plant responses to drought stress in sugarcane (Saccharum officinarum) (Fonseca et al 2022), and enhanced growth in hydroponic lettuce (Lactuca sativa) under normal conditions and high EC (Moncada et al 2020). Trichoderma is a beneficial fungus with a symbiotic relationship with plants by enhancing resistance to root pathogens through the enzymatic breakdown of the pathogen's cell walls (Guzm an-Guzm an et al 2023).…”