PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

This study aimed to isolate and characterize endophytic bacteria from rice leaves for their potential to suppress Bacterial Leaf Blight (BLB) and promote plant growth. A total of 45 endophytic bacterial isolates were obtained from the healthy leaf samples of MTU-1010, BPT-5204 and NLR-34449 cultivars and out of which, 19 isolates were from Nellore district, 26 isolates were from Chittoor district. The endophytic bacterial count from BPT 5204 cultivar collected from Madibaka village of Yerpedu mandal, Chittoor district showed highest count of 7.8 × 10⁶/g leaf. Whereas samples collected from the Nelaballi village of Pellakuru mandal, Nellore district of MTU 1010 variety recorded lowest colony forming units 2.4 × 10⁶/g of leaf.  45 Endophytic bacterial isolates were evaluated for the antagonistic efficacy by Agar well Diffusion method. Among 45 isolates, EMP-5 recorded highest zone of inhibition with 16.8 mm and 12 isolates recorded with inhibition zone diameter of more than 10.00 mm. Morphological characterization of the 12 isolates revealed that dominance of Gram negative bacteria with rod shaped cells over the Gram positive bacteria. With regard to Plant Growth Promoting (PGP) traits of 12 isolates, EMP-5 showed positive to all PGP trait namely, IAA production, Phosphate solubilization, Siderophore production, HCN, Ammonia Production, Amylase activity and Protease production. These findings highlight the potential EMP-5 endophytic bacteria as eco-friendly biocontrol and biofertilizer agents for rice cultivation.