title: Rice UDP-glucose pyrophosphorylase1 is essential for pollen callose deposition and its cosuppression results in a new type of thermosensitive genic male sterility.
abstract: UDP-glucose pyrophosphorylase (UGPase) catalyzes the reversible production of glucose-1-phosphate and UTP to UDP-glucose and pyrophosphate. The rice (Oryza sativa) genome contains two homologous UGPase genes, Ugp1 and Ugp2. We report a functional characterization of rice Ugp1, which is expressed throughout the plant, with highest expression in florets, especially in pollen during anther development. Ugp1 silencing by RNA interference or cosuppression results in male sterility. Expressing a double-stranded RNA interference construct in Ugp1-RI plants resulted in complete suppression of both Ugp1 and Ugp2, together with various pleiotropic developmental abnormalities, suggesting that UGPase plays critical roles in plant growth and development. More importantly, Ugp1-cosuppressing plants contained unprocessed intron-containing primary transcripts derived from transcription of the overexpression construct. These aberrant transcripts undergo temperature-sensitive splicing in florets, leading to a novel thermosensitive genic male sterility. Pollen mother cells (PMCs) of Ugp1-silenced plants appeared normal before meiosis, but during meiosis, normal callose deposition was disrupted. Consequently, the PMCs began to degenerate at the early meiosis stage, eventually resulting in complete pollen collapse. In addition, the degeneration of the tapetum and middle layer was inhibited. These results demonstrate that rice Ugp1 is required for callose deposition during PMC meiosis and bridges the apoplastic unloading pathway and pollen development.
authors.affiliation: Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors.forename: Rongzhi
authors.initials: R
authors.lastname: Chen
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhao
authors.forename: Zhe
authors.initials: Z
authors.lastname: Shao
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wei
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wang
authors.forename: Lili
authors.initials: L
authors.lastname: Zhu
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.forename: Mengxiang
authors.initials: M
authors.lastname: Sun
authors.forename: Ruifeng
authors.initials: R
authors.lastname: He
authors.forename: Guangcun
authors.initials: G
authors.lastname: He
mesh_terms: D005718:Gametogenesis; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D006720:Homozygote; D008969:Molecular Sequence Data; D012275:Oryza / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D051479:Plant Infertility / Q000235:genetics*; D030821:Plants, Genetically Modified; D011058:Pollen / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D034622:RNA Interference; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D019076:Transgenes; D005957:UTP-Glucose-1-Phosphate Uridylyltransferase / Q000235:genetics / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D005957:UTP-Glucose-1-Phosphate Uridylyltransferase