PROTEIN-KINASE ACTIVITY IN DIFFERENT STAGES OF POTATO (SOLANUM-TUBEROSUM L) MICROTUBERIZATION

In vitro culture was used to study morphogenetic aspects of the tuberi zation process under controlled conditions in potato (Solanum tuberosu m L.) plants. This paper accurately defines four stages of tuber devel opment and their correlation to external morphological characteristics and histological structures. Protein kinase activity, assayed in each stage using Histone IIAS as substrate, was differentially expressed d uring the tuberization process. Phosphorylation was maximum in the fir st stages of tuber formation. The incorporation of [(PO4-)-P-32] to en dogenous peptides containing serine/threonine amino acidic residues fo llowed the same pattern that the protein kinase activity did.