Effect of temperature on Pi54- mediated leaf blast resistance in rice

AbstractAssessment of temperature effect on plant resistance against diseases has become essential under climate change scenario as temperature rise is anticipated to modify host resistance. To determine temperature influence on resistance gene, a pair of near-isogenic rice lines differing for thePi54 resistance gene was assessed against leaf blast. Blast resistance was determined as the extent of infection efficiency (IE) and sporulation (SP) at suboptimal (22  °C and 32 °C) and optimal temperature (27 °C) of pathogen aggressiveness. Relative resistance for IE and SP was higher at suboptimal temperature as compared to that of optimal temperature. Maximum level of resistance was at 22 °C where higher levels of expression ofPi54 and defence-regulatory transcription factorWRKY45 were also noted. At 32  °C, although some level of resistance noted, but level ofPi54 andWRKY45 expression was too low, suggesting that resistance recorded at higher temperature was due to reduced pathogen aggressiveness. At the optimal temperature for pathogen aggressiveness, comparatively lower levels ofPi54 andWRKY45 expression suggest possible temperature-induced interruption of the defence processes. The variation in resistance patterns modulated by temperature is appeared to be due to pathogen ’s sensitivity to temperature that leads to varying levels ofPi54 gene activation. Quick and violent activity of the pathogen at optimal temperature came into sight for the interruption of defenc...
Source: World Journal of Microbiology and Biotechnology - Category: Microbiology Source Type: research