Preussia sp. BSL-10 producing nitric oxide, gibberellins, and indole acetic acid and improving rice plant growth

Preussia sp. have been least known to improve plant growth and produce phytohormones. The current study investigated the production of nitric oxide (NO), indole-3-acetic acid (IAA), and gibberellins (GA₄, GA₇, GA₁₅, and GA₅₃) by a novel endophytic-fungal strain Preussia sp. BSL-10 using advanced chromatographic and spectroscopic techniques. Production of these phytohormones were validated by RT–PCR analysis, which indicated the expression of genes encoding tryptophan synthase (TRP), indole-3-acetamide hydrolase (IAAH), tryptophan-2-monooxygenase (IAAM), aldehyde dehydrogenase (ALD), GA₄ desaturase (DES), geranylgeranyl-diphosphate synthase (GGS2), ent-desaturase oxidase (P450-4), GA₁₄ synthase (P450-1) and nitrite reductase (NIRK/NIRS), cytochrome P450 (P450nor), nitrate reductase (NR), NOS-like (NOL), and nitric oxide reductase (QNOR/CNOR). In plant growth-promoting effects, the inoculation of Preussia sp. BSL-10 significantly increased the growth of dwarf mutant Waito-C and wild-type rice cultivars. In conclusion, utilizing new endophytic with the ability to produce NO, IAA, and gibberellins can be used to promote growth and yield of marginalized crops.