Seed biostimulant Bacillus sp. MGW9 improves the salt tolerance of maize during seed germination

Abstract

Crop performance is seriously affected by high salt concentrations in soils. To develop improved seed pre-sowing treatment technologies, it is crucial to improve the salt tolerance of seed germination. Here, we isolated and identified the strain Bacillus sp. MGW9 and developed the seed biostimulant MGW9. The effects of seed biopriming with the seed biostimulant MGW9 in maize (Zea mays L.) under saline conditions were studied. The results show that the strain Bacillus sp. MGW9 has characteristics such as salt tolerance, nitrogen fixation, phosphorus dissolution, and indole-3-acetic acid production. Seed biopriming with the seed biostimulant MGW9 enhanced the performance of maize during seed germination under salinity stress, improving the germination energy, germination percentage, shoot/seedling length, primary root length, shoot/seedling fresh weight, shoot/seedling dry weight, root fresh weight and root dry weight. Seed biostimulant MGW9 biopriming also alleviated the salinity damage to maize by improving the relative water content, chlorophyll content, proline content, soluble sugar content, root activity, and activities of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase, while decreasing the malondialdehyde content. In particular, the field seedling emergence of maize seeds in saline-alkali soil can be improved by biopriming with the seed biostimulant MGW9. Therefore, maize seed biopriming with the seed biostimulant MGW9 could be an effective approach to overcoming the inhibitory effects of salinity stress and promoting seed germination and seedling growth.

Microbiome engineering and plant biostimulants for sustainable crop improvement and mitigation of biotic and abiotic stresses

“…They indicated that the beneficial effects might be due to (i) decreased cell membrane lipid peroxidation, (ii) increased chlorophyll content and antioxidant enzyme activities, and (iii) a better efflux and compartmentation of intracellular ions. Other studies on applying PBs to reduce the deleterious effects of salinity stress have also been reported in several food crops, such as rice [136], maize [134], lettuce [137], cucumber [114], and tomato [90].…”

“…For example, maize seeds primed with microbial PBs containing Bacillus sp. MGW9 increased the stress tolerance of the maize plants grown in saline-alkali soil [134]. When analyzing two contrasting (salt susceptible and tolerant) rice cultivars under salinity stress conditions, Khan et al [116] found that the natural biostimulant panchagavya significantly enhanced biochemical and physiological characteristics in both cultivars.…”

Prospects for Abiotic Stress Tolerance in Crops Utilizing Phyto- and Bio-Stimulants

“…Since biostimulants are derived from diversity of sources like plants, humic substances, protein hydrolysate, seaweed extracts, macro-and micro-alga, living microbial cultures and plant growth-promoting microbes (PGPM), etc., these compounds are therefore poorly characterized and their mode of actions are also undefined at cellular and molecular levels. Thus, due to the current knowledge gaps the concepts of PBs are still evolving (Calvo et al, 2014;Li et al, 2021), which is somewhat indicative of the diversity of inputs that can be accepted as PBs.…”

Identification of a Negative Regulator for Salt Tolerance at Seedling Stage via a Genome-Wide Association Study of Thai Rice Populations

“…Growth parameters, such as SRW, SDW, RFW, and RDW, have been used to determine salt stress responses and tolerance in various species, such as cotton [31], maize [32,33], tomato [34], wheat [35], eggplant [36], and rice [9]. RWC and CMS have also been used to assess salt tolerance.…”