BABA as chemical inducer of potato resistance to Phytophthora infestans

OLIVIERI, F. P.; GUEVARA, M. G; WOLSKI, E. A; GONZALEZ ALTAMIRANDA, E.; LOBATO, C.; DALEO, G. R.; ANDREU A. B.

Misiones, Argentina

Congreso; XL REUNION ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIONES EN BIOQUIMICA Y BIOLOGIA MOLECULAR (SAIB).; 2004

SOCIEDAD ARGENTINA DE INVESTIGACIONES EN BIOQUIMICA Y BIOLOGIA MOLECULAR (SAIB).

     Several strategies for controlling leaf and tuber diseases have been introduced over the years, but serious losses in potato harvest still occur. The use of chemicals that induce resistance was tried as an alternative. The aim of this work was to investigate the biochemical mechanisms by which the BABA (ß-amino-butyric acid) increases resistance in potato leaves against P. infestans.      Plants of two potato cultivars: cv. Pampeana (resistant) and Bintje (susceptible) were treated with BABA, as chemical inducer. Three or twenty days after treatment, leaves were inoculated with P. infestans. The highest level of protection against P. infestans was observed after 3 days of treatment with BABA, although this  protection decreased in foliage at 20 days of treatment in both cultivars. The levels of phytoalexin and phenols were increased only at 20 days in treated leaves from plants of both cultivars.      The expression of two PR proteins (basic chitinases and aspartic proteases) was analyzed at 24 and 48 hs after inoculation with P. infestans for both times of treatment with BABA (3 and 20 days). In cv. Pampeana, the expression of these enzymes was increased in plants with 3 days of treatment; this induction decreased at 20 days. In cv. Bintje, the effect of BABA on the induction of these enzymes was less evident. Future efforts will focuse in the  analysis of these enzymes in tubers from treated plants.