title: A putative lipase gene EXTRA GLUME1 regulates both empty-glume fate and spikelet development in rice.
abstract: Recent studies have shown that molecular control of inner floral organ identity appears to be largely conserved between monocots and dicots, but little is known regarding the molecular mechanism underlying development of the monocot outer floral organ, a unique floral structure in grasses. In this study, we report the cloning of the rice EXTRA GLUME1 (EG1) gene, a putative lipase gene that specifies empty-glume fate and floral meristem determinacy. In addition to affecting the identity and number of empty glumes, mutations in EG1 caused ectopic floral organs to be formed at each organ whorl or in extra ectopic whorls. Iterative glume-like structures or new floral organ primordia were formed in the presumptive region of the carpel, resulting in an indeterminate floral meristem. EG1 is expressed strongly in inflorescence primordia and weakly in developing floral primordia. We also found that the floral meristem and organ identity gene OsLHS1 showed altered expression with respect to both pattern and levels in the eg1 mutant, and is probably responsible for the pleiotropic floral defects in eg1. As a putative class III lipase that functionally differs from any known plant lipase, EG1 reveals a novel pathway that regulates rice empty-glume fate and spikelet development.
authors.affiliation: The State Key Laboratory of Rice Biology, College of Life Sciences, Zhejiang University, Hangzhou, 310029 China.
authors.forename: Haoge
authors.initials: H
authors.lastname: Li
authors.forename: Dawei
authors.initials: D
authors.lastname: Xue
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Gao
authors.forename: Meixian
authors.initials: M
authors.lastname: Yan
authors.forename: Wenying
authors.initials: W
authors.lastname: Xu
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Xing
authors.forename: Danian
authors.initials: D
authors.lastname: Huang
authors.forename: Qian
authors.initials: Q
authors.lastname: Qian
authors.forename: Yongbiao
authors.initials: Y
authors.lastname: Xue
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D035264:Flowers / Q000235:genetics / Q000254:growth & development*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008049:Lipase / Q000235:genetics / Q000378:metabolism*; D018519:Meristem / Q000235:genetics / Q000254:growth & development; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018749:RNA, Plant / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D010940:Plant Proteins; D018749:RNA, Plant; D008049:Lipase