Halotolerant endophytic bacteria alleviate salinity stress in rice (oryza sativa L.) by modulating ion content, endogenous hormones, the antioxidant system and gene expression

• Published in: BMC plant biology 2023-10, Vol.23 (1), p.1-494, Article 494
• Main Authors: Asif, Saleem, Jan, Rahmatullah, Kim, Nari, Asaf, Sajjad, Khan, Muhammad Aaqil, Kim, Eun-Gyeong, Jang, Yoon-Hee, Bhatta, Dibya, Lee, In-Jung, Kim, Kyung-Min
• Format: Article
• Language: English
• Subjects: Abiotic stress; Abscisic acid; Agricultural practices; Agricultural production; Agricultural research; Antioxidants; Artemisia princeps; Bacteria; Biosynthesis; Brevibacterium pityocampae; Chenopodium ficifolium; Chlorophyll; Crop production; Endocrine disruptors; Endophytes; Environmental aspects; Flavonoids; Gene expression; Genetic aspects; Genetic engineering; Halophilic bacteria; Hardiness; Hormones; Inductively coupled plasma mass spectrometry; Inoculation; Ion channels; Jasmonic acid; Lysinibacillus fusiformis; Lysinibacillus sphaericus; Magnesium; Mass spectrometry; Mass spectroscopy; Minerals; Oryza sativa; Phylogenetics; Physiological aspects; Physiology; Plant growth; Plant hormones; Plants; Rice; Rice (Oryza sativa L.); Salicylic acid; Salinity; Salinity effects; Salinity stress; Salinity tolerance; Salt; Salt stress (Botany); Sodium chloride; Strains (organisms)
• ISSN: 1471-2229; 1471-2229
• DOI: 10.1186/s12870-023-04517-z

Excessive salinity reduces crop production and negatively impacts agriculture worldwide. We previously isolated endophytic bacterial strains from two halophytic species: Artemisia princeps and Chenopodium ficifolium. We used three bacterial isolates: ART-1 (Lysinibacillus fusiformis), ART-10 (Lysinibacillus sphaericus), and CAL-8 (Brevibacterium pityocampae) to alleviate the impact of salinity stress on rice. The impact of 160 mM NaCl salinity on rice was significantly mitigated following inoculation with these bacterial strains, resulting in increased growth and chlorophyll content. Furthermore, OsNHX1, OsAPX1, OsPIN1 and OsCATA expression was increased, but OsSOS expression was decreased. Inductively coupled plasma mass spectrometry (ICP-MS) revealed reduced K.sup.+ and Na.sup.+ levels in shoots of bacteria-inoculated plants, whereas that of Mg.sup.2+ was increased. Bacterial inoculation reduced the content of total flavonoids in rice leaves. Salinized plants inoculated with bacteria showed reduced levels of endogenous salicylic acid (SA) and abscisic acid (ABA) but increased levels of jasmonic acid (JA). In conclusion, the bacterial isolates ART-1, ART-10, and CAL-8 alleviated the adverse effect of salinity on rice growth, which justifies their use as an eco-friendly agricultural practice.