RELATIONSHIPS BETWEEN PHENOLICS-CONJUGATED POLYAMINES AND SENSITIVITYOF SUGARCANE TO SMUT (USTILAGO-SCITAMINEA)

infection of sugarcane buds (var, Barbados 42231) with teliospores of Ustilago scitaminea changes the pattern of polyamine conjugation in se veral organs of e-month-old plants. Stalks of infected plants contain SH-spermidine that does not occur in the healthy organ. Similar result s have been obtained for SH-spermine in the first expanded leaf and in the stem. The amount of SH-cadaverine in the first expanded leaf, roo ts and stem of infected plants is always higher than that found for he althy plants. Some phenolics are also associated with different polyam ine fractions, So, the amount of p-hydroxybenzoic acid in both SH and PH fractions of polyamines extracted from the root increases after inf ection. Syringic acid is the main phenol associated with the PH fracti on in the first expanded leaf of infected plants, whereas this phenol is mainly associated with both SH and PH fractions isolated from the s tem and the whip, Infection enhances conjugation of p-coumaric acid to PH polyamines, whereas caffeic acid appears in the SH fraction in lea f, root and stem. However, ferulic acid seems to be the main hydroxyci nnamic acid derivative in the whip. Chlorogenic acid is associated wit h the SH fraction from the stem of healthy plants although this change s to free phenolics after infection.