title: Live and let die - the B(sister) MADS-box gene OsMADS29 controls the degeneration of cells in maternal tissues during seed development of rice (Oryza sativa).
abstract: B(sister) genes have been identified as the closest relatives of class B floral homeotic genes. Previous studies have shown that B(sister) genes from eudicots are involved in cell differentiation during ovule and seed development. However, the complete function of B(sister) genes in eudicots is masked by redundancy with other genes and little is known about the function of B(sister) genes in monocots, and about the evolution of B(sister) gene functions. Here we characterize OsMADS29, one of three MADS-box B(sister) genes in rice. Our analyses show that OsMADS29 is expressed in female reproductive organs including the ovule, ovule vasculature, and the whole seed except for the outer layer cells of the pericarp. Knock-down of OsMADS29 by double-stranded RNA-mediated interference (RNAi) results in shriveled and/or aborted seeds. Histological analyses of the abnormal seeds at 7 days after pollination (DAP) indicate that the symplastic continuity, including the ovular vascular trace and the nucellar projection, which is the nutrient source for the filial tissue at early development stages, is affected. Moreover, degeneration of all the maternal tissues in the transgenic seeds, including the pericarp, ovular vascular trace, integuments, nucellar epidermis and nucellar projection, is blocked as compared to control plants. Our results suggest that OsMADS29 has important functions in seed development of rice by regulating cell degeneration of maternal tissues. Our findings provide important insights into the ancestral function of B(sister) genes.
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, PR China.
authors.forename: Xuelian
authors.initials: X
authors.lastname: Yang
authors.forename: Feng
authors.initials: F
authors.lastname: Wu
authors.forename: Xuelei
authors.initials: X
authors.lastname: Lin
authors.forename: Xiaoqiu
authors.initials: X
authors.lastname: Du
authors.forename: Kang
authors.initials: K
authors.lastname: Chong
authors.forename: Lydia
authors.initials: L
authors.lastname: Gramzow
authors.forename: Susanne
authors.initials: S
authors.lastname: Schilling
authors.forename: Annette
authors.initials: A
authors.lastname: Becker
authors.forename: Günter
authors.initials: G
authors.lastname: Theißen
authors.forename: Zheng
authors.initials: Z
authors.lastname: Meng
mesh_terms: D056625:Endosperm / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant / Q000235:genetics; D018525:Germination; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism; D009928:Organ Specificity / Q000235:genetics; D012275:Oryza / Q000166:cytology* / Q000235:genetics* / Q000254:growth & development; D056771:Ovule / Q000166:cytology* / Q000235:genetics; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D058526:Plant Vascular Bundle / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D019655:Quantitative Trait, Heritable; D012639:Seeds / Q000166:cytology / Q000235:genetics* / Q000254:growth & development*; D013213:Starch / Q000378:metabolism
chemical_list: D026161:MADS Domain Proteins; D010940:Plant Proteins; D013213:Starch