Location: Location not imported yet.Title: Influence of temperature regimes on resistance gene-mediated response to rice bacterial blight Author
|Vera Cruz, Casiana M|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/6/2011
Publication Date: 10/6/2011
Citation: Vera Cruz, C., Baliion, J., Webb, K.M., Choi, I., Mauleon, R., Goodwin, P., Satoh, K., Kikuchi, S., Garrett, K., Leach, J. 2011. Influence of temperature regimes on resistance gene-mediated response to rice bacterial blight. Meeting Abstract. ICBB Meeting. Seoul, South Korea October 6-8, 2010. Interpretive Summary:
Technical Abstract: Increasing temperatures could reduce yield growth rate of rice by 10% in several rice production areas. Similarly, higher temperatures are predicted to accelerate the breakdown of plant disease resistance through higher disease pressure or altered resistance (R) gene effectiveness in many host-pathogen systems. Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is generally severe particularly in susceptible varieties at higher temperatures. To improve our understanding of the nature of the various components of rice-Xoo interaction, we are studying the factors responsible for durability of R genes in rice to Xoo. BB R gene Xa4 is less effective in certain backgrounds at high temperatures while Xa7 restricted disease and Xoo population size more effectively at high than at low temperatures creating fluctuating selection, thereby positively impacting durability of Xa7. Transcript profiling through microarray of IRBB4 (Xa4)-PXO145 interaction was done to determine candidate genes that may be involved in Xa4 resistance against Xoo. Expression levels of these candidates were compared by RT-PCR in PXO145-inoculated IRBB4 and IRBB7 (Xa7) at high and low temperature regimes (35/31oC and 29/21oC day/night) to elucidate the temperature dependent response of these R genes to BB. Disease development at high and low temperature regimes was assessed in clip-inoculated plants and bacterial population counts of the whole leaf were obtained at 11-day post inoculation. There was no significant differences in the bacterial population in plants incubated at high and low temperature regimes but differences in lesion lengths were observed. This may suggest host regulation of pathogen spread and not pathogen multiplication as a form of disease resistance.