A novel PGPR strain, Streptomyces lasalocidi JCM 3373T, alleviates salt stress and shapes root architecture in soybean by secreting indole‐3‐carboxaldehyde

• Published in: Plant, cell and environment Vol. 47; no. 6; pp. 1941 - 1956
• Main Authors: Lu, Liang, Liu, Ning, Fan, Zihui, Liu, Minghao, Zhang, Xiaxia, Tian, Juan, Yu, Yanjun, Lin, Honghui, Huang, Ying, Kong, Zhaosheng
• Format: Journal Article
• Language: English
• Published: Oxford Wiley Subscription Services, Inc 01.06.2024
• Subjects: Abiotic stress; Chemical analysis; Crop production; Gene expression; Genes; Glycine max; indole‐3‐carboxaldehyde; Inoculation; Microorganisms; PGPR; Plant growth; root architecture; Salinity tolerance; salt stress; Salt tolerance; Soybeans; Strain; Streptomyces; Streptomyces lasalocidi JCM 3373T; Streptomycetes; Vegetable oils; Yeast
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/pce.14847

While soybean (Glycine max L.) provides the most important source of vegetable oil and protein, it is sensitive to salinity, which seriously endangers the yield and quality during soybean production. The application of Plant Growth‐Promoting Rhizobacteria (PGPR) to improve salt tolerance for plant is currently gaining increasing attention. Streptomycetes are a major group of PGPR. However, to date, few streptomycetes has been successfully developed and applied to promote salt tolerance in soybean. Here, we discovered a novel PGPR strain, Streptomyces lasalocidi JCM 3373T, from 36 strains of streptomycetes via assays of their capacity to alleviate salt stress in soybean. Microscopic observation showed that S. lasalocidi JCM 3373T does not colonise soybean roots. Chemical analysis confirmed that S. lasalocidi JCM 3373T secretes indole‐3‐carboxaldehyde (ICA1d). Importantly, IAC1d inoculation alleviates salt stress in soybean and modulates its root architecture by regulating the expression of stress‐responsive genes GmVSP, GmPHD2 and GmWRKY54 and root growth‐related genes GmPIN1a, GmPIN2a, GmYUCCA5 and GmYUCCA6. Taken together, the novel PGPR strain, S. lasalocidi JCM 3373T, alleviates salt stress and improves root architecture in soybean by secreting ICA1d. Our findings provide novel clues for the development of new microbial inoculant and the improvement of crop productivity under salt stress. Summary statement Streptomyces lasalocidi JCM 3373T, selected from 36 species of streptomycetes, alleviates salt tolerance and shapes root architecture by secreting a metabolite‐indole‐3‐carboxaldehyde in soybean.