Beneficial Fungal Secretome and Synthetic Consortia to Improve Soybean Growth During Drought Stress

Beneficial endophytic fungi may improve crop stress tolerance through soil carbon storage, water and nutrient acquisition, and stress mitigation. Our goal was to build a naturally occurring fungal synthetic community (FunSynCom) to improve growth and drought resilience in soybeans. In this study, we isolated, identified, and characterized a set of fungal endophytes from the rhizosphere of halophytic plants during a low-tide summer with reduced soil moisture levels. Fungal strains were screened for plant growth-promoting traits like organic acid and extracellular enzyme production (leucine-aminopeptidase [LAP], phosphatase [PHOS], β-xylosidase [BX]; quinic, citric, succinic, and maleic acids). Individual strains were screened in plant growth assays. Based on the screening results, we designed FunSynCom. The FunSynCom was composed of Sclerostagonospora lathyri (F3), Tremateia chromolaenae (F7), Chaetosphaeronema sp. (F15), Xylariales sp. (F25), and Lophiostoma terricola (F36). Soybean plants were inoculated with FunSynCom and individual strains and placed under drought stress. Phenotypic data were collected across a 21-day growth period, including shoot length, stomatal conductance to water vapor (GSW), leaf–air vapor pressure deficit (VPD). Across metrics, responses varied by inoculation and treatment. Sclerostagonospora lathyri appeared to have the most favorable drought performance of the SynCom strains. Chaetosphaeronema sp. increased root-to-shoot ratio under drought. ΔVPD was lower than the drought control across all inoculations, while ΔGSW diverged by strain under drought (Chaetosphaeronema sp. Higher vs control; Xylariales sp.(F25) Lower vs control; S. lathyri ≈ control). FunSynCom performed comparably to the control for biomass under drought; antioxidant enzymes (polyphenol oxidase, PPO; peroxidase, POD) were highest in the drought control, with within-strain increases most evident for Chaetosphaeronema sp. (and PPO in Xylariales sp.); overall responses were strain-specific rather than uniformly beneficial. Future work will incorporate transcriptomic and root exudate analyses to define host–microbe interactions and improve FunSynCom composition in longer, nutrient-limited assays to refine community design.

Author dc:creator

• Owens, Lucille Alia 1998-

Contributors dc:contributor

• Khan, Abdul Latif
• Chitrala, Kumaraswamy Naidu
• Tobin, Michael

• Fungal Endophyte
• Soybean
• Drought
• Synthetic Community

Language dc:language

English

Handle dc:identifier.uri

https://hdl.handle.net/10657/20848

OAI identifier oai:identifier

oai:tdl-ir.tdl.org:10657/20848