Krishnaswamy, Sowmya , Srivastava, Sanjeeva , Mohammadi, Mohsen , Rahman, Muhammad , Deyholos, Michael K. , Kav, Nat N. V. .
Dissecting the role(s) of PR 10 proteins by transcriptional profiling.
Pathogenesis-related (PR) proteins are part of a plantís defense response and include the PR 10 families which are small, acidic, and intracellular proteins. Some PR 10 genes are induced in response to both abiotic and biotic stresses whereas others may be constitutively expressed in certain organs suggesting their involvement in plant defense responses as well as normal growth and development. However, the biological activity of PR 10 proteins are not clearly known, although in some cases ribonuclease (RNase) or ligand-binding activities have been suggested or demonstrated. Recently, we have demonstrated that the constitutive, heterologous expression of cDNAs encoding pea (Pisum sativum L.) PR 10 proteins, which are RNases, in Brassica napus and Arabidopsis thaliana enhance germination, early seedling growth and confer tolerance to multiple stresses. Their expression also results in phenotypic traits such as precocious flowering, a higher degree of lateral branching, and increased numbers of seed pods, phenotypes that have been reported to be mediated through cytokinins (CKs). A direct correlation between the expression of pea PR 10 cDNAs and endogenous CKs was also demonstrated in our transgenic models. The mechanism(s) through which the PR 10 protein modulates the CK concentration and whether CKs play a role in mediating the observed responses in these transgenic plants is currently being investigated. Here we report the results from our investigation into a pea PR 10-mediated global change in A. thaliana gene expression which has identified a number of genes whose expression is affected presumably because of the transgene. These include genes that are involved in defense, plant growth and development which are consistent with the observed phenotype of these transgenic plants. Furthermore, most of the identified genes have been previously reported to be regulated by CKs. Our results will be discussed within the context of the RNase activity of the pea PR 10 protein and the possible mechanisms by which endogenous CK concentrations may be modulated by it.
Log in to add this item to your schedule
1 - University of Alberta, Agricultural, Food and Nutritional Science, 4-10 Ag. Forestry Center, Edmonton, AB, T6G 2P5, Canada
2 - University of Alberta, Agricultural, Food and Nutritional Science
3 - University of Alberta, Biological Sciences
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM