Olvera-Carillo, Yadira , Reyes, Jose Luis , Campos, Francisco , Covarrubias, Alejandra .
Functional analysis of Hydrophlins LEA4 in Arabidopsis thaliana in drought adaptive response.
LEA proteins (Late Embryogenesis Abundant) accumulate during late seed development, at the onset of dehydration, and in vegetative tissues subjected to water deficit. These proteins can be classified in six families based on their sequence homology and, because their physicochemical characteristics, most of them belong to a more widespread group of proteins called hydrophilins, found in different kingdoms. Different types of evidence suggest a role for these proteins as protectors of other macromolecules by providing preferential hydration environments during water scarcity. To understand the function of these proteins, in this work we have focused on the functional analysis of the LEA 4 family of Arabidopsis thaliana. We show that the over-expression of one of the members of this family (AtLEA4-5) confers tolerance to severe drought in adult plants as well as an increased floral bud number. In addition, we have followed a “loss of function” approach by analysis of plants obtained by post-transcriptional silencing, through RNAi and miRNA for one or two family members, and of mutants produced by transposon insertion. The deficiency of one or two of the members of this family lead to sensitive phenotypes upon water limitation, either during germination in presence of osmotic-ionic stress or in re-hydrated adult plants after being subjected to mild dehydration conditions. In addition, these plants showed a decrease in the number of floral and axillary buds, suggesting a protective function to meristems to prevent the damage that stress conditions might cause. This is the first direct evidence showing that one of the LEA protein families is involved in the adaptive response of higher plants to water deficit.
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1 - Universidad Nacional Autónoma de México, Instituto de Biotecnología, Biología Molecular de Plantas, Av. Universidad 1001 Col. Chamilpa, Cuernavaca, Morelos, 62210, Mexico
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM