Salicylic acid signaling and bacterial root colonization in rice Garcha Seema*, Chopra S Department of Microbiology, Punjab Agricultural University, Ludhiana-141004, Punjab *Corresponding author: sgarcha@pau.edu
Online published on 28 September, 2023. Abstract Salicylic acid (SA), a plant defence hormone, is one of the compounds present in the root exudates. It helps in organization of root microbiome of the plant. The present study was undertaken to correlate SA content with bacterial root colonization in widely cultivated Asian rice varieties, Parmal/Non- Basmati (PR121, PR122 and PR126) and Basmati varieties (Punjab Basmati number 3- Pb Bas-3; Punjab Basmati number 5- Pb Bas 5and Pusa Basmati- PusaBas 1121) and a wild variety (Labra). Standard microbiological procedures were used for bacterial isolation on various selective media for enumeration of total viable count, count of spore formers, free-living nitrogen fixers, symbiotic nitrogen fixers, Gram negative and Gram positive bacteria. Salicylic acid was estimated using High Performance Liquid Chromatography (HPLC). Results revealed that the root endophytic population establishes itself between 60 and 90 days after transplant (DAT). Increase in SA content, from time of transplant to 60 DAT, was commensurate with bacterial invasion of root tissue. Decrease in SA concentration at 90 DAT facilitated the rice root colonization. Persistence of SA throughout the cultivation time period kept the defense system at high alert. No disease was encountered throughout the cultivation time period of this study. Top Keywords Asian rice varieties, Basmati, Parmal/Non-Basmati, Root microbiome, Salicylic acid. Top |