Poster: Signaling, cell-to-cell

Abs # 435: The Expression Patterns and Physiological Functions of CML23 AND CML24 (TCH2)

Presenter:	Delk, Nikki A., nadelk@rice.edu
Authors	Delk, Nikki A. (A)   Johnson, Keith A. (A)   Braam, Janet  (A)
Affiliations:	(A): Rice University

Arabidopsis CML23 and CML24 (TCH2) contain calcium-binding domains and belong to the calmodulin-like (CML) family. Calmodulin is an essential protein in eukaryotes that regulates various intracellular processes in a calcium-dependent manner. CML23 and CML24 are 78% identical to each other at the amino acid level and share 40% identity with CaM. I am conducting expression and mutant analysis to elucidate CML23 and CML24 function. CML23 and CML24 may function in areas associated with flower development, water regulation, and mechanical stress. CML23::GUS and CML24::GUS reporter transgenics have similar GUS expression patterns, including in developing flowers, at hydathodes, and at branch points. I am conducting RNA analysis to confirm these findings. CML24 may have a role in plant responses to the environment. CML24 transcript levels increase in response various environmental stimuli, including darkness, touch, and temperature shock. Plants with reduced CML24 mRNA levels are altered in flowering time, abscisic acid sensitivity, and salt tolerance. I am continuing to analyze cml23 and cml24 mutants and transgenics for altered phenotypes under various environmental conditions and to elucidate CML23 and CML24 expression in response to various stimuli. Understanding CML23 and CML24 expression patterns and physiological functions may provide more insight into the roles of calcium and calcium-binding proteins in plant development and response to the environment. NIH 1F31GM66371-01, NSF IBN0313432, NSF IBN9982654