Temperature sensitivity of the hypersensitive response of bell pepper to Xanthomonas axonopodis pv. vesicatoria

• Published in: Phytopathology Vol. 92; no. 2; pp. 197 - 203
• Main Authors: ROMERO, A. M, KOUSIK, C. S, RITCHIE, D. F
• Format: Journal Article
• Language: English
• Published: St. Paul, MN American Phytopathological Society 01.02.2002
• Subjects: Agronomy. Soil science and plant productions; avrBs1 gene; avrBs2 gene; avrBs3 gene; Bacterial plant pathogens; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Genetics and breeding of economic plants; Microbiology; Pest resistance; Phytopathology. Animal pests. Plant and forest protection; Plant pathogens; Systematics. Structure, properties and multiplication. Genetics; Varietal selection. Specialized plant breeding, plant breeding aims; Xanthomonas axonopodis; Pseudomonadales; Incompatibility; Temperature; Incubation; Xanthomonas axonopodis; Hypersensitivity; Ionic conductivity; Bell pepper; Strain; Resistance; Sensitivity; Gene; Dicotyledones; Angiospermae; Race; Bacteria; Pseudomonadaceae; Capsicum annuum; Spermatophyta; Infiltration; Solanaceae
• ISSN: 0031-949X; 1943-7684
• DOI: 10.1094/PHYTO.2002.92.2.197

ABSTRACT When bacterial spot-resistant pepper plants carrying resistance gene Bs2 and infiltrated with incompatible strains of Xanthomonas axonopodis pv. vesicatoria carrying a functional avrBs2 gene (races P1 and P3) were incubated at 32 degrees C, they exhibited an electrolyte leakage and bacterial multiplication pattern in planta similar to that obtained with a compatible strain (race P4) carrying a nonfunctional avrBs2 gene. They also developed disease-like symptoms. Pretreatment of incompatible bacteria at 32 degrees C before infiltration caused a delay in electrolyte leakage less pronounced than that caused by exposing plants to 32 degrees C. Also, plants had to be exposed to 32 degrees C for an hour prior to inoculation to increase symptom expression. These data suggest that the Bs2 gene is temperature sensitive. In other experiments, the avrBs1-Bs1 interaction appeared to be the most heat tolerant and thus the least likely to revert to compatible, whereas the avrBs3-Bs3 interaction had an intermediate sensitivity to elevated temperatures.