Sd. Guzzo et Emf. Martins, LOCAL AND SYSTEMIC INDUCTION OF BETA-1,3-GLUCANASE AND CHITINASE IN COFFEE LEAVES PROTECTED AGAINST HEMILEIA VASTATRIX BY BACILLUS-THURINGIENSIS, Journal of phytopathology, 144(9-10), 1996, pp. 449-454
beta-1,3-glucanase and chitinase activities were induced locally and s
ystemically 4-25 and 11-25 days, respectively, after spraying the surf
ace of the third pair of coffee leaves from the apex of 8-month-old pl
ants with a 50 mg/ml aqueous suspension of Bacillus thuringiensis in a
commercial formulation (Thuricide HP-Sandoz). The treatment also indu
ced local and systemic resistance against Hemileia vastatrix after the
application of the inducer. Within 14-18 days of application of the T
huricide inducer, the beta-1,3-glucanase activity in the locally- and
systemically-protected unchallenged leaves reached maximum levels of 2
26% and 279% higher levels respectively, than in control plants. The c
hitinase activity reached maximum levels of 224% and 181% respectively
, within 18-21 days after treatment with the inducer. Two beta-1,3-glu
canase bands were detected by native PAGE electrophoresis in extracts
from locally-and systemically-protected unchallenged coffee leaves.