The fungal endophyte Metarhizium anisopliae (MetA1) coordinates salt tolerance mechanisms of rice to enhance growth and yield

• Published in: Plant physiology and biochemistry 2024-02, Vol.207, p.108328-108328, Article 108328
• Main Authors: Chowdhury, Md. Zahid Hasan, Mostofa, Mohammad Golam, Mim, Mahjabin Ferdaous, Haque, Md. Ashraful, Karim, M. Abdul, Sultana, Razia, Rohman, Md Motiar, Bhuiyan, Ashkar-Ul-Alam, Rupok, Md. Rahat Bari, Islam, Shah Mohammad Naimul
• Format: Article
• Language: English
• Subjects: agar; Antioxidant enzymes; ascorbate peroxidase; biomass; catalase; electrolyte leakage; endophytes; flavonoids; fungi; glutathione transferase; growth and development; hydrogen peroxide; leaf relative water content; leaves; malondialdehyde; Metarhizium anisopliae; Oxidative damage; peroxidase; phenol; photosynthesis; plant growth; proline; Rice; salinity; Salt stress; salt tolerance; Yield
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2023.108328

The implementation of salt stress mitigation strategies aided by microorganisms has the potential to improve crop growth and yield. The endophytic fungus Metarhizium anisopliae shows the ability to enhance plant growth and mitigate diverse forms of abiotic stress. We examined the functions of M. anisopliae isolate MetA1 (MA) in promoting salinity resistance by investigating several morphological, physiological, biochemical, and yield features in rice plants. In vitro evaluation demonstrated that rice seeds primed with MA enhanced the growth features of rice plants exposed to 4, 8, and 12 dS/m of salinity for 15 days in an agar medium. A pot experiment was carried out to evaluate the growth and development of MA-primed rice seeds after exposing them to similar levels of salinity. Results indicated MA priming in rice improved shoot and root biomass, photosynthetic pigment contents, leaf succulence, and leaf relative water content. It also significantly decreased Na+/K+ ratios in both shoots and roots and the levels of electrolyte leakage, malondialdehyde, and hydrogen peroxide, while significantly increasing proline content in the leaves. The antioxidant enzymes catalase, glutathione S-transferase, ascorbate peroxidase, and peroxidase, as well as the non-enzymatic antioxidants phenol and flavonoids, were significantly enhanced in MA-colonized plants when compared with MA-unprimed plants under salt stress. The MA-mediated restriction of salt accumulation and improvement in physiological and biochemical mechanisms ultimately contributed to the yield improvement in salt-exposed rice plants. Our findings suggest the potential use of the MA seed priming strategy to improve salt tolerance in rice and perhaps in other crop plants. [Display omitted] •Seed priming with Metarhizium anisopliae (MetA1) enhances rice growth under salt stress.•MA priming improves the defense mechanisms of rice plants against salt stress.•MA increases rice yield under salt stress.•Seed priming with MA can be considered a potential salt stress mitigation strategy.