rotunda2 mutants identify a role for the LEUNIG gene in vegetative leaf morphogenesis

• Published in: Journal of experimental botany 2004-07, Vol.55 (402), p.1529-1539
• Main Authors: Cnops, G, Jover-Gil, S, Peters, J.L, Neyt, P, Block, S. de, Robles, P, Ponce, M.R, Gerats, T, Micol, J.L, Lijsebettens, M. van
• Format: Article
• Language: English
• Subjects: Alleles; Amino Acid Sequence; amino acid sequences; Arabidopsis - cytology; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - genetics; Arabidopsis thaliana; Biological and medical sciences; cell differentiation; Cell division; cell expansion; Cell growth; Cell lines; cell proliferation; Cell Size; Chromosomes, Plant - genetics; clones; Conserved Sequence; DNA Primers; Epidermal cells; Fundamental and applied biological sciences. Psychology; gene expression; Genes; Genes. Genome; Genetic mutation; histology; leaf development; Leaves; Microscopy, Interference - methods; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Morphogenesis; mutants; nucleotide sequences; Oryza - genetics; Petioles; Phenotype; Plant cells; Plant Leaves - genetics; Plant Leaves - growth & development; Plants; real time reverse-transcriptase PCR; Research Papers: Regulation of Growth, Development and Whole Organism Physiology; Restriction Mapping; Reverse Transcriptase Polymerase Chain Reaction; Sequence Alignment; sequence analysis; Sequence Homology, Amino Acid; Transcription Factors - chemistry; Transcription Factors - genetics; transcriptional activation
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/erh165

Leaf development in Arabidopsis thaliana is considered to be a two-step process. In the first step, a leaf primordium is formed that involves a switch from indeterminate to leaf developmental fate in the shoot apical meristem cells. The second step, known as leaf morphogenesis, consists of post-initiation developmental events such as patterned cell proliferation, cell expansion, and cell differentiation. The results are presented of the molecular and genetic analyses of the rotunda2 (ron2) mutants of Arabidopsis, which were isolated based on their wide and serrated vegetative leaf lamina. The RON2 gene was positionally cloned and was identical to LEUNIG (LUG); it encodes a transcriptional co-repressor that has been described to affect flower development. Morphological and histological analyses of expanded leaves indicated that RON2 (LUG) acts at later stages of leaf development by restricting cell expansion during leaf growth. Real-time reverse-transcription polymerase chain reaction was used to quantify the expression of KNOX, WUSCHEL, YABBY3, LEAFY, ASYMMETRIC LEAVES, and GIBBERELLIN OXIDASE genes in expanding and fully expanded rosette leaf laminas of the wild type and ron2 and lug mutants. SHOOTMERISTEMLESS was expressed in wild-type leaves and down-regulated in the mutants. The results indicate that RON2 (LUG) has a function in later stages of leaf development.