HSR203 antisense suppression in tobacco accelerates development of hypersensitive cell death

Tronchet, M Ranty, B Marco, Y Roby, D

M. Tronchet et al., HSR203 antisense suppression in tobacco accelerates development of hypersensitive cell death, PLANT J, 27(2), 2001, pp. 115-127

68

INGLESE

Article

Plant Sciences","Animal & Plant Sciences

PLANT JOURNAL

0960-7412 → ACNP

27

2

2001

115 - 127

ISI

0960-7412(200107)27:2<115:HASITA>2.0.ZU;2-N

Activation of the tobacco gone hsr203 is rapid, highly localized, specific for incompatible plant-pathogen interactions, and strongly correlated with programmed cell death occurring in response to diverse pathogens. Functiona l characterization of hsr203 gene product has shown that HSR203 is a serine hydrolase that displays esterase activity, We show here that transgenic to bacco plants deficient in HSR203 protein exhibit an accelerated hypersensit ive response when inoculated with an avirulent strain of Ralstonia solanace arum. This response was accompanied by a maximal level of cell death and a drastic inhibition of in planta bacterial growth. Transgenic plants deficie nt in HSR203 were also found to show increased resistance in a dosage-depen dent manner to Pseudomonas syringae pv. pisi, another avirulent bacterial p athogen, and to virulent and avirulent races of Phytophthora parasitica, a fungal pathogen of tobacco, but not to different virulent bacteria. Surpris ingly, expression of another hsr gene, hsr515, and that of the defence gene s PR1-a and PR5, was strongly reduced in the transgenic lines. Our results suggest that hsr203 antisense suppression in tobacco can have pleiotropic e ffects on HR cell death and defence mechanisms, and induces increased resis tance to different pathogens.