Use of Antagonistic Peptide Technology to Determine the CLE Peptides that Regulate Root Growth in Arabidopsis

Abstract

Plants constantly produce cells that form tissues and organs from their meristems. During development, patterned cell divisions and cell fate specification through cell-cell communication play a key role in organ shape and organization. The root apical meristem (RAM) of Arabidopsis is the source of many cell types in the root and requires intrinsic and extrinsic factors for development and maintenance; bidirectional signaling between stem and mature cells contributes to RAM activity, and its organization in Arabidopsis is a useful model to determine discrete signaling mechanisms in plant growth and morphogenesis. CLE peptides are intercellular signals in plant development. They are encoded by members of the CLE gene family, which produce small proteins believed to play a role in stem cell maintenance. The Tax lab demonstrated that CLE peptides have a differential regional effect on the root, promoting proliferation in the quiescent center and inhibiting cell division in the transit amplifying region, overall suppressing root growth (unpublished data). The goal is to determine which CLE peptides contribute to these differential effects in Arabidopsis roots. With antagonistic peptide technology, single residues in CLE peptides can be modified and cause specific phenotypes, such as disruption of stem cell maintenance, as seen by Song et al when replacing the sixth glycine residue to a threonine in CLV3. This technology can be used to characterize these signals, and ultimately better evaluate the role of CLE peptides in plant development. We plan to alter residues in CLE peptides and treat roots with the mutant peptides to determine what effect they have on different regions of the root and in mutant backgrounds. Song et al Plant Physiology 161.3 2013