Function of the signaling peptides AtRALF25 and AtRALF26 in the pollen grain germination and in the pollen tube growth

Abstract

In recent decades, peptides with similar action to hormonal peptides in animals have been discovered in plants. These signaling peptides are involved with defense response, stress response, differentiation and development. An example of these signaling peptides is RALF, a ubiquitous peptide in the plant kingdom and it is involved with the regulation of cell expansion. The isoforms AtRALF25 and 26 of RALF peptide family in Arabidopsis have a high expression level in pollen grain and, possibly, they have an important role in the regulation of pollen tube germination and growth. Due to the potential for regulating expansion of the pollen tube and the consequent importance in the Arabidopsis reproductive system, the objective of this project is the functional characterization of the peptides AtRALF25 and 26. The strategy will be determine the activity of RALF peptides through biological assays as inhibition of pollen tube growth, inhibition of root growth, inhibition of hypocotyl elongation, alkalinization assay and promoter analysis fused to GFP. This propose is part of a major doctoral project, where is intended to understand the role of RALF isoforms in the communication between gametophytic and sporophytic tissues. The resulting information of this project can contribute for a possible biotechnological application of these peptides on the manipulation of plant reproductive system.