Induction of Systemic Resistance against Bacterial Leaf Streak Disease and Growth Promotion in Rice Plant by Streptomyces shenzhenesis TKSC3 and Streptomyces sp. SS8

Abstract

The genus Streptomyces demonstrates enormous promise in promoting plant growth and protecting plants against various pathogens. Single and consortium treatments of two selected Streptomyces strains ( Streptomyces shenzhenensis TKSC3 and Streptomyces sp. SS8) were evaluated for their growth-promoting potential on rice, and biocontrol efficiency through induced systemic resistance (ISR) mediation against Xanthomonas oryzae pv. oryzicola ( Xoc ), the causal agent of rice bacterial leaf streak (BLS) disease. Seed bacterization by Streptomyces strains improved seed germination and vigor, relative to the untreated seed. Under greenhouse conditions, seed bacterization with consortium treatment TKSC3 + SS8 increased seed germination, root length, and dry weight by 20%, 23%, and 33%, respectively. Single and consortium Streptomyces treatments also successfully suppressed Xoc infection. The result was consistent with defense-related enzyme quantification wherein single and consortium Streptomyces treatments increased peroxidase (POX), polyphenol oxidase, phenylalanine ammonia-lyase, and β,1–3 glucanase (GLU) accumulation compared to untreated plant. Within all Streptomyces treatments, consortium treatment TKSC3 + SS8 showed the highest disease suppression efficiency (81.02%) and the lowest area under the disease progress curve value (95.79), making it the best to control BLS disease. Consortium treatment TKSC3 + SS8 induced the highest POX and GLU enzyme activities at 114.32 μmol/min/mg protein and 260.32 abs/min/mg protein, respectively, with both enzymes responsible for plant cell wall reinforcement and resistant interaction. Our results revealed that in addition to promoting plant growth, these Streptomyces strains also mediated ISR in rice plants, thereby, ensuring protection from BLS disease.

Biofertilizers: An ecofriendly technology for nutrient recycling and environmental sustainability

“…SS8) was applied in rice and the treatments suppressed ISR-mediated bacterial leaf streak (BLS) disease caused by infection of Xanthomonas oryzae pv. oryzicola (Xoc) ( Hata et al, 2021 ). Streptomyces treatments (both single and consortium) increased peroxidase (POX), polyphenol oxidase, phenylalanine ammonia-lyase, and β,1–3 glucanase (GLU) accumulation compared to untreated plant.…”

Characterization of Streptomyces spp. from Rice Fields as a Potential Biocontrol Agent against Burkholderia glumae and Rice Plant Growth Promoter

“…The effects of bacterial seed treatment on germination and vigor index in rice were determined under laboratory and greenhouse conditions [33,45]. In laboratory conditions, 25 seeds inoculated with each antagonistic isolate were incubated in a sterile plastic container (30 cm in diameter) impregnated with sterile moistened tissue paper (45 cm × 28 cm).…”

“…Among bacterial groups, Streptomyces spp. were broadly examined as biocontrol agents due to their plant growth-promoting (PGP) and biocontrol characteristics [31][32][33]. Streptomyces spp.…”

Salicylate Glucoside as a Nontoxic Plant Protectant Alternative to Salicylic Acid

“…Salicylic acid (SA) is a multifaceted plant hormone that regulates responses to biotic and abiotic stresses. , Exogenously applied SA significantly reduced the disease severity of various crops from viral, bacterial, and fungal infections by inducing local and systemic acquired resistance (SAR). − SAR is a long-term plant “immune” response that provides systemic protection for the whole plant from future pathogenic infections . Externally applied SA or SA analogs, such as 2,6-dichloroisonicotinic acid (INA) and benzothiadiazole (BTH), also conferred resistance to pathogenic attacks. − SA and SA analogs modulate SAR by triggering the expression of pathogenesis-related (PR) genes and other genes relevant to defense. − Besides biotic stresses, exogenously supplied SA also protects plants from various abiotic stresses such as drought, heat, chilling, salt, cadmium, and freezing. , Since SA and other salicylates are naturally produced and some of them, such as aspirin, also reduce chronic human diseases, using SA as a plant protectant is expected to have minimal side effects to the environment and humans .…”