Leaf Rolling Controlled by the Homeodomain Leucine Zipper Class IV Gene Roc5 in Rice

• Published in: Plant physiology (Bethesda) Vol. 156; no. 3; pp. 1589 - 1602
• Main Authors: Zou, Liang-ping, Sun, Xue-hui, Zhang, Zhi-guo, Liu, Peng, Wu, Jin-xia, Tian, Cai-juan, Qiu, Jin-long, Lu, Tie-gang
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Biologists 01.07.2011
• Subjects: Arabidopsis thaliana; Biological and medical sciences; Cell Count; Cell lines; Cell Nucleus - metabolism; Cell Size; DNA, Bacterial - genetics; Epidermal cells; Fundamental and applied biological sciences. Psychology; Genes; Genes, Plant - genetics; Genetic Complementation Test; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; Leaves; Leucine Zippers - genetics; Molecular Sequence Data; Mutagenesis, Insertional - genetics; Mutation - genetics; Oryza - cytology; Oryza - genetics; Oryza - physiology; Oryza sativa; Phenotype; Phenotypes; Photosynthesis - physiology; Plant cells; Plant Leaves - cytology; Plant Leaves - genetics; Plant Leaves - physiology; Plant physiology and development; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Stomata - physiology; Plant Transpiration - physiology; Plants; Plants, Genetically Modified; Polymerase chain reaction; Protein Transport; Rice; RNA Interference; Suppression, Genetic; SYSTEMS BIOLOGY, MOLECULAR BIOLOGY, AND GENE REGULATION; Transgenic plants; Monocotyledones; Oryza; Gene; Plant physiology; Gramineae; Angiospermae; Herbaceous plant; Spermatophyta; Plant leaf; Leucine
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.111.176016

Leaf rolling is considered an important agronomic trait in rice (Oryza sativa) breeding. To understand the molecular mechanism controlling leaf rolling, we screened a rice T-DNA insertion population and isolated the outcurved leaf1 (oul1) mutant showing abaxial leaf rolling. The phenotypes were caused by knockout of Rice outermost cell-specific gene5 (Roc5), an ortholog of the Arabidopsis (Arabidopsis thaliana) homeodomain leucine zipper class IV gene GLABRA2. Interestingly, overexpression of Roc5 led to adaxially rolled leaves, whereas cosuppression of Roc5 resulted in abaxial leaf rolling. Bulliform cell number and size increased in oull and Roc5 cosuppression plants but were reduced in Roc5-overexpressing lines. The data indicate that Roc5 negatively regulates bulliform cell fate and development. Gene expression profiling, quantitative polymerase chain reaction, and RNA interference (RNAi) analyses revealed that Protodermal Factor Like (PFL) was probably down-regulated in oul1. The mRNA level of PFL was increased in Roc5-overexpressing lines, and PFL-RNAi transgenic plants exhibit reversely rolling leaves by reason of increases of bulliform cell number and size, indicating that Roc5 may have a conserved function, these are, to our knowledge, the first functional data for a gene encoding a homeodomain leucine zipper class IV transcriptional factor in rice that modulates leaf rolling.