Poster: Vegetative Development

Abs # 417: Callose and Plant Development

Presenter:	Enns, Linda C., lenns@u.washington.edu
Authors	Enns, Linda C. (A)   Cleland, Robert E. (A)
Affiliations:	(A): U. of Washington

Callose, a b-1,3 glucan, has been implicated in multiple aspects of plant growth and development: cell plate formation, wound response, general cell wall deposition and plasmodesmal regulation, to name a few. Because of a lack of callose mutants, however, there is very little genetic evidence towards its specific roles in plant development. There are 12 putative callose synthase isoforms encoded by the Arabidopsis genome. Eight of these are expressed in the Arabidopsis root. We have used a reverse genetic strategy called Targeting Induced Local Lesions IN Genomes (TILLING) to identify several mutants containing a variety of point mutations in these 8 genes. These mutants, in combination with T-DNA insertion mutants acquired from The Salk Institute Genomic Analysis Laboratory (SIGnAL) have provided us with an extensive library of mutant alleles for each of the 8 genes, predicted to cause phenotypic defects along a spectrum of severity. We are currently analyzing these mutants. We are especially interested in the role of callose in intercellular communication, since we have found that treating Arabidopsis roots with a callose synthesis inhibitor, chlorpromazine (CPZ), results in the loss of symplastic domains in the root meristem, as well as causes root developmental defects such as agravitropism. We hope that our mutants will shed more light on these, and others' studies.