Plant-Growth Promotion and Biocontrol Properties of Three Streptomyces spp. Isolates to Control Bacterial Rice...

Area of Science:

• Microbiology
• Plant Pathology
• Agricultural Science

Background:

• Bacterial Panicle Blight (BPB), caused by Burkholderia glumae, significantly impacts global rice production.
• Developing effective biocontrol strategies is crucial for sustainable agriculture and food security.

Purpose of the Study:

• To evaluate three Streptomyces isolates as biocontrol agents against B. glumae.
• To assess their plant-growth promoting abilities for integrated crop management.
• To identify antimicrobial compounds produced by promising isolates.

Main Methods:

• In vitro inhibition assays against B. glumae and other pathogens.
• Assessment of plant growth-promoting traits (siderophores, IAA, enzymes, phosphate solubilization).
• Greenhouse experiments on rice cultivars, including gnotobiotic studies with GFP-tagged strains and mass spectrometry for compound identification.

Main Results:

• Two isolates (A20, 5.1) inhibited B. glumae and other microbes; isolate 7.1 showed antifungal activity.
• Streptomyces A20 colonized rice plants, promoted growth in two cultivars, and associated with root hairs.
• Mass spectrometry identified Streptotricins D, E, and F produced by isolate A20.

Conclusions:

• Streptomyces isolate A20 shows significant potential as a biocontrol agent against rice bacterial diseases.
• Its ability to promote plant growth and produce novel antimicrobial compounds enhances its value for sustainable rice cultivation.