Location: Plant Gene Expression CenterTitle: Comprehensive analysis of CLE polypeptide signaling gene expression and over-expression activity in Arabidopsis Author
Submitted to: Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2010
Publication Date: 9/30/2010
Publication URL: http:///www.plantphysiol.org/cgi/reprint/pp.110.163683v1
Citation: Jun, J.H., Fiume, E., Roeder, A.H., Meng, L., Sharma, V.K., Osmont, K.S., Baker, C., Ha, C.M., Meyerowitz, E.M., Feldman, L.J., Fletcher, J.C. 2010. Comprehensive analysis of CLE polypeptide signaling gene expression and over-expression activity in Arabidopsis. Plant Physiology. 154:1721-1736. Interpretive Summary: In this study we determined the expression patterns of 23 members of the Arabidopsis CLE gene family in roots, leaves, stems, flowers and fruits. We found that each CLE gene has a highly distinct and specific expression pattern, with no two being precisely alike. We also discovered that most tissues examined express multiple CLE genes in unique but overlapping patterns. In addition, we identified mutant alleles of nine CLE genes, four of which cause complete loss of gene function and five of which reduce gene function. None of these mutants had obvious developmental defects, suggesting that one CLE gene can compensate for the loss of another. Our findings provide a more complete picture of those aspects of plant growth and development that may be controlled by small protein signaling pathways, and provide a community resource of CLE-related plant and DNA materials.
Technical Abstract: Intercellular signaling is essential for the coordination of growth and development in higher plants. Although hundreds of putative receptors have been identified in Arabidopsis thaliana, only a few families of extracellular signaling molecules have been discovered and their biological roles are largely unknown. To expand our insight into the developmental processes potentially regulated by ligand-mediated signal transduction pathways, we undertook a systematic expression analysis of the members of the Arabidopsis CLAVATA3/ESR-RELATED (CLE) small signaling polypeptide family. Using reporter constructs we show that the CLE genes have distinct and specific patterns of promoter activity. We find that each Arabidopsis tissue expresses at least one CLE gene, indicating that CLE-mediated signaling pathways are likely to play roles in many biological processes during the plant life cycle. Some CLE genes that are closely related in sequence have dissimilar expression profiles, yet in many tissues multiple CLE genes have overlapping patterns of promoter-driven reporter activity. This observation, plus the general absence of detectable morphological phenotypes in cle null mutants, suggests a high degree of functional redundancy exists among CLE gene family members. Our work establishes a community resource of CLE-related biological materials and provides a platform for understanding and ultimately manipulating many different plant signaling systems.