title: GLUCAN SYNTHASE-LIKE 5 (GSL5) plays an essential role in male fertility by regulating callose metabolism during microsporogenesis in rice.
abstract: Callose plays an important role in pollen development in flowering plants. In rice, 10 genes encoding putative callose synthases have been identified; however, none of them has been functionally characterized. In this study, a rice Glucan Synthase-Like 5 (GSL5) knock-out mutant was isolated that exhibited a severe reduction in fertility. Pollen viability tests indicated that the pollen of the mutant was abnormal while the embryo sac was normal. Further, GSL5-RNA interference transgenic plants phenocopied the gsl5 mutant. The RNA expression of GSL5 was found to be knocked out in the gsl5 mutant and knocked down in GSL5-RNA interference transgenic plants by real-time reverse transcripion-PCR (RT-PCR) analysis. The male sterility of the mutant was due to abnormal microspore development; an analysis of paraffin sections of the mutant anthers at various developmental stages revealed that abnormal microspore development began in late meiosis. Both the knock-out and knock-down of GSL5 caused a lack of callose in the primary cell wall of meiocytes and in the cell plate of tetrads. As a result, the callose wall of the microspores was defective. This was demonstrated by aniline blue staining and an immunogold labeling assay; the microspores could not maintain their shape, leading to premature swelling and even collapsed microspores. These data suggest that the callose synthase encoded by GSL5 plays a vital role in microspore development during late meiosis and is essential for male fertility in rice.
authors.affiliation: Biotechnology Research Institute/National Key Facility for Gene Resources and Gene Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China These authors contributed equally to this work.
authors.forename: Xiao
authors.initials: X
authors.lastname: Shi
authors.affiliation: Biotechnology Research Institute/National Key Facility for Gene Resources and Gene Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China These authors contributed equally to this work.
authors.forename: Xuehui
authors.initials: X
authors.lastname: Sun
authors.affiliation: Biotechnology Research Institute/National Key Facility for Gene Resources and Gene Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Biotechnology Research Institute/National Key Facility for Gene Resources and Gene Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Feng
authors.affiliation: Biotechnology Research Institute/National Key Facility for Gene Resources and Gene Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Biotechnology Research Institute/National Key Facility for Gene Resources and Gene Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Lida
authors.initials: L
authors.lastname: Han
authors.affiliation: Biotechnology Research Institute/National Key Facility for Gene Resources and Gene Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China wujinxia@caas.cn lutiegang@caas.cn.
authors.forename: Jinxia
authors.initials: J
authors.lastname: Wu
authors.affiliation: Biotechnology Research Institute/National Key Facility for Gene Resources and Gene Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China wujinxia@caas.cn lutiegang@caas.cn.
authors.forename: Tiegang
authors.initials: T
authors.lastname: Lu
mesh_terms: D002473:Cell Wall / Q000378:metabolism; D005298:Fertility; D056130:Gametogenesis, Plant; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D005936:Glucans / Q000378:metabolism*; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D012275:Oryza / Q000201:enzymology* / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011058:Pollen / Q000235:genetics / Q000648:ultrastructure; D034622:RNA Interference; D012098:Reproduction; D013194:Staining and Labeling
chemical_list: D005936:Glucans; D010940:Plant Proteins; C048306:callose; D005964:Glucosyltransferases; C040232:glucan synthase
keywords: Callose; Male fertility; Microspore development; Pollen viability; Rice (Oryza sativa)