Role of Endogenous Salicylic Acid as a Hormonal Intermediate in the Bacterial Endophyte Bacillus subtilis -Induced Protection of Wheat Genotypes Contrasting in Drought Susceptibility under Dehydration

• Published in: Plants (Basel) Vol. 11; no. 23; p. 3365
• Main Authors: Lastochkina, Oksana, Ivanov, Sergey, Petrova, Svetlana, Garshina, Darya, Lubyanova, Alsu, Yuldashev, Ruslan, Kuluev, Bulat, Zaikina, Evgenia, Maslennikova, Dilara, Allagulova, Chulpan, Avtushenko, Irina, Yakupova, Albina, Farkhutdinov, Rashit
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 03.12.2022; MDPI
• Subjects: 1-aminobenzotriazole; Accumulation; Agricultural production; Bacillus subtilis; Bacteria; Biosynthesis; Climate change; Cultivars; Dehydration; Drought; Drought resistance; drought tolerance; Endophytes; endophytic Bacillus subtilis; Environmental impact; Genotype & phenotype; Genotypes; Lipid peroxidation; Lipids; Microorganisms; Peroxidation; Plant growth; Plant resistance; Productivity; Proline; Salicylic acid; Seedlings; Strain; Triticum aestivum; Triticum aestivum L; Water damage; Wheat; Triticum aestivum L; drought tolerance; 1-aminobenzotriazole; salicylic acid; endophytic Bacillus subtilis
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants11233365

Endophytic is a non-pathogenic beneficial bacterium which promotes plant growth and tolerance to abiotic stresses, including drought. However, the underlying physiological mechanisms are not well understood. In this study, the potential role that endogenous salicylic acid (SA) plays in regulating endophytic -mediated drought tolerance in wheat ( L.) was examined. The study was conducted on genotypes with contrasting levels of intrinsic drought tolerance (drought-tolerant (DT) cv. Ekada70; drought-susceptible (DS) cv. Salavat Yulaev). It was revealed that 10-4 promoted endogenous SA accumulation and increased the relative level of transcripts of the gene, a marker of the SA-dependent defense pathway, but two wheat cultivars responded differently, with the highest levels exhibited in DT wheat seedlings. These had a positive correlation with the ability of strain 10-4 to effectively protect DT wheat seedlings against drought injury by decreasing osmotic and oxidative damages (i.e., proline, water holding capacity (WHC), and malondialdehyde (MDA)). However, the use of the SA biosynthesis inhibitor 1-aminobenzotriazole prevented endogenous SA accumulation under normal conditions and the maintenance of its increased level under stress as well as abolished the effects of treatment. Particularly, the suppression of strain 10-4-induced effects on proline and WHC, which are both contributing factors to dehydration tolerance, was found. Moreover, the prevention of strain 10-4-induced wheat tolerance to the adverse impacts of drought, as judged by the degree of membrane lipid peroxidation (MDA) and plant growth (length, biomass), was revealed. Thus, these data provide an argument in favor of a key role of endogenous SA as a hormone intermediate in triggering the defense responses by 10-4, which also afford the foundation for the development of the bacterial-induced tolerance of these two different wheat genotypes under dehydration.