GRAS proteins belong to a plant-specific transcription factor family. Currently, 33 GRAS members including a putative expressed pseudogene have been identified in the Arabidopsis genome. With a reverse genetic approach, we have constructed a "phenome-ready unimutant collection" of the GRAS genes in Arabidopsis thaliana. Of this collection, we focused on loss-of-function mutations in 23 novel GRAS members. Under standard conditions, homozygous mutants have no obvious morphological phenotypes compared with those of wild-type plants. Expression analysis of GRAS genes using quantitative real-time RT-PCR (qRT-PCR), microarray data mining, and promoter::GUS reporter fusions revealed their tissue-specific expression patterns. Our analysis of protein-protein interaction and subcellular localization of individual GRAS members indicated their roles as transcription regulators. In our yeast two-hybrid (Y2H) assay, we confirmed the protein-protein interaction between SHORT-ROOT (SHR) and SCARECROW (SCR). Furthermore, we identified a new SHR-interacting protein, SCARECROW-LIKE23 (SCL23), which is the most closely related to SCR. Our large-scale analysis provides a comprehensive evaluation on the Arabidopsis GRAS members, and also our phenome-ready unimutant collection will be a useful resource to better understand individual GRAS proteins that play diverse roles in plant growth and development.
Bibliographical noteFunding Information:
Acknowledgments The authors wish to thank ABRC, NASC, and RIKEN for providing the seeds and cDNA clones. We also thank Yrjo Helariutta for critical reading of the manuscript. We are also grateful to In A Kim and Ji Hye Yoon for technical assistance and plant maintenance. This work was supported by grants from Plant Signaling Network Research Center (R11-2003-008-03004-0) and KRF (C00469) to MML; KOSEF (R01-2006-000-11026-0), KRF (C00131), Crop Functional Genomics Center (CG1123), and Bio-Green 21 to JL.
All Science Journal Classification (ASJC) codes
- Agronomy and Crop Science
- Plant Science