ibclogo XVI International Botanical Congess


Abstract Number: 5812
Poster No. = 2194


ROLE OF PROTEIN KINASES DURING PHYSIOLOGICAL TRANSITIONS OF THE MOSS Funaria hygrometrica.


D'Souza, Jacinta S. and Johri, M.M., Tata Institute of Fundamental Research, Dept. of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Rd., Colaba, Mumbai-400 005.


The protonema of the moss Funaria hygrometrica is made up of chloronema and caulonema cells. In the presence of the plant hormone indole-acetic acid, chloronema cells differentiate to form caulonema. On the other hand, the presence of abscisic acid, the newly forming laterals on the caulonema filaments form brood cells. The current project aims at understanding the role of protein kinases in these physiological transitions. Using biochemical and immunological techniques, the following results have been obtained. 1. The moss Funaria hygrometrica contains several protein kinases (both Ca2+ - dependent and -independent, ranging from 125 to 38 kDa). 2. A 44 kDa (PK44) calmodulin domain-like protein kinase (CDPK) shows increase in its activity up to 48 hours in the hormone-treated cells as compared to the control. 3. A 38 kDa (PK38) mitogen-activated protein kinase (MAPK) shows increase in activity within 2 minutes of the addition of ABA or NaC1 to caulonemal cells. 4. A Ca2+ -dependent, calmodulin-stimulated protein kinase (PK70) has been purified to homogeneity from the chloronema cells. High titer antibodies have also been raised to this PK. However, no role has been attributed to this kinase. These observations and the multiplicity of protein kinases in the protonema of the moss will be discussed.


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