Semi-rolled leaf1 encodes a putative glycosylphosphatidylinositol-anchored protein and modulates rice leaf rolling by regulating the formation of bulliform cells.
Leaf rolling is an important agronomic trait in rice (Oryza sativa) breeding and moderate leaf rolling maintains the erectness of leaves and minimizes shadowing between leaves, leading to improved photosynthetic efficiency and grain yields. Although a few rolled-leaf mutants have been identified and some genes controlling leaf rolling have been isolated, the molecular mechanisms of leaf rolling still need to be elucidated. Here we report the isolation and characterization of SEMI-ROLLED LEAF1 (SRL1), a gene involved in the regulation of leaf rolling. Mutants srl1-1 (point mutation) and srl1-2 (transferred DNA insertion) exhibit adaxially rolled leaves due to the increased numbers of bulliform cells at the adaxial cell layers, which could be rescued by complementary expression of SRL1. SRL1 is expressed in various tissues and is expressed at low levels in bulliform cells. SRL1 protein is located at the plasma membrane and predicted to be a putative glycosylphosphatidylinositol-anchored protein. Moreover, analysis of the gene expression profile of cells that will become epidermal cells in wild type but probably bulliform cells in srl1-1 by laser-captured microdissection revealed that the expression of genes encoding vacuolar H(+)-ATPase (subunits A, B, C, and D) and H(+)-pyrophosphatase, which are increased during the formation of bulliform cells, were up-regulated in srl1-1. These results provide the transcript profile of rice leaf cells that will become bulliform cells and demonstrate that SRL1 regulates leaf rolling through inhibiting the formation of bulliform cells by negatively regulating the expression of genes encoding vacuolar H(+)-ATPase subunits and H(+)-pyrophosphatase, which will help to understand the mechanism regulating leaf rolling.
National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032 Shanghai, China.
Jing-Jing
JJ
Xiang
Guang-Heng
GH
Zhang
Qian
Q
Qian
Hong-Wei
HW
Xue
D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D017343:Genes, Plant / Q000235:genetics; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D043564:Inorganic Pyrophosphatase / Q000378:metabolism; D061346:Laser Capture Microdissection; D008954:Models, Biological; D016254:Mutagenesis, Insertional / Q000235:genetics; D009154:Mutation / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000166:cytology* / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D019441:Plant Epidermis / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D018515:Plant Leaves / Q000166:cytology* / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D021122:Protein Subunits / Q000378:metabolism; D021381:Protein Transport; D025262:Vacuolar Proton-Translocating ATPases / Q000378:metabolism
D004269:DNA, Bacterial; D017261:Glycosylphosphatidylinositols; D010940:Plant Proteins; D021122:Protein Subunits; C036483:T-DNA; D025262:Vacuolar Proton-Translocating ATPases; D043564:Inorganic Pyrophosphatase