Biopriming of Maize Seeds with a Novel Bacterial Strain SH-6 to Enhance Drought Tolerance in South Korea

Abstract

Maize is the third most common cereal crop worldwide, after rice and wheat, and plays a vital role in preventing global hunger crises. Approximately 50% of global crop yields are reduced by drought stress. Bacteria as biostimulants for biopriming can improve yield and enhance sustainable food production. Further, seed biopriming stimulates plant defense mechanisms. In this study, we isolated bacteria from the rhizosphere of Artemisia plants from Pohang beach, Daegu, South Korea. Twenty-three isolates were isolated and screened for growth promoting potential. Among them, bacterial isolate SH-6 was selected based on maximum induced tolerance to polyethylene glycol-simulated drought. SH-6 showed ABA concentration = 1.06 ± 0.04 ng/mL, phosphate solubilizing index = 3.7, and sucrose concentration = 0.51 ± 0.13 mg/mL. The novel isolate SH-6 markedly enhanced maize seedling tolerance to oxidative stress owing to the presence of superoxide dismutase, catalase, and ascorbate peroxidase activities in the culture media. Additionally, we quantified and standardized the biopriming effect of SH-6 on maize seeds. SH-6 significantly increased maize seedling drought tolerance by up to 20%, resulting in 80% germination potential. We concluded that the novel bacterium isolate SH-6 (gene accession number (OM757882) is a biostimulant that can improve germination performance under drought stress.

The phytomicrobiome: solving plant stress tolerance under climate change

“…For example, biopriming of maize seeds with GA-producing bacterial strains showed markedly enhanced maize seedling tolerance to oxidative stress. This also improved drought tolerance by up to 20% ( Shaffique et al., 2022 ). When the rhizobacterium Azospirillum brasilense was introduced to the roots of Arabidopsis, the host plant displayed increased endogenous abscisic acid (ABA) levels and drought tolerance ( Eichmann et al., 2021 ).…”

Seed biopriming as a promising approach for stress tolerance and enhancement of crop productivity: a review

“…Bioprimed plants exhibit robust and rapid defence responses against different abiotic stresses. Shaffique et al 86 reported that biopriming with Enterobacter ludwigii stimulated defence response in maize (Z. mays L.) plants under water-deficit stress conditions resulting in drought tolerance and enhanced germination percentage of maize (Z. mays L.) seedlings. Priming with T. harzianum and Phanerochaete chrysosporium enhanced defence enzymes activities to alleviate salinity stress induced oxidative damage in soybean (G. max L.) and wheat (T. aestivum L.) plants, respectively.…”

“…Bioprimed plants exhibit robust and rapid defence responses against different abiotic stresses. Shaffique et al 86 . reported that biopriming with Enterobacter ludwigii stimulated defence response in maize ( Z. mays L.) plants under water‐deficit stress conditions resulting in drought tolerance and enhanced germination percentage of maize ( Z. mays L.) seedlings.…”

Effects of priming duration and concentration of metabolites from rhizosphere bacteria on the germinability of cowpea, soybean, sesame, and okra seeds

“…The beneficial effects of seed priming on a variety of crops have been confirmed. [1][2][3][4] Although priming, as a plant-growth enhancement technique, can be applied at many stages in the developmental cycle of a plant, seed treatment is popular due to its practicality and simplicity.…”