Protein kinase activity in different stages of potato (Solanum tuberosum L.) microtuberization.

In vitro culture was used to study morphogenetic aspects of the tuberization process under controlled conditions in potato (Solanum tuberosum L.) plants. This paper accurately defines four stages of tuber development and their correlation to external morphological characteristics and histological structures. Protein kinase activity, assayed in each stage using Historic HAS as substrate, was differentially expressed during the tuberization process. Phosphorylation was maximum in the first stages of tuber formation. The incorporation of [ ³² PO ₄ ^-1 ] to endogenous peptides containing serine/threonine amino acidic residues followed the same pattern that the protein kinase activity did.