title: The Arabidopsis CALLOSE DEFECTIVE MICROSPORE1 gene is required for male fertility through regulating callose metabolism during microsporogenesis.
abstract: During angiosperm microsporogenesis, callose serves as a temporary wall to separate microsporocytes and newly formed microspores in the tetrad. Abnormal callose deposition and dissolution can lead to degeneration of developing microspores. However, genes and their regulation in callose metabolism during microsporogenesis still remain largely unclear. Here, we demonstrated that the Arabidopsis (Arabidopsis thaliana) CALLOSE DEFECTIVE MICROSPORE1 (CDM1) gene, encoding a tandem CCCH-type zinc finger protein, plays an important role in regulation of callose metabolism in male meiocytes and in integrity of newly formed microspores. First, quantitative reverse transcription PCR and in situ hybridization analyses showed that the CDM1 gene was highly expressed in meiocytes and the tapetum from anther stages 4 to 7. In addition, a transfer DNA insertional cdm1 mutant was completely male sterile. Moreover, light microscopy of anther sections revealed that microspores in the mutant anther were initiated, and then degenerated soon afterward with callose deposition defects, eventually leading to male sterility. Furthermore, transmission electron microscopy demonstrated that pollen exine formation was severely affected in the cdm1 mutant. Finally, we found that the cdm1 mutation affected the expression of callose synthesis genes (CALLOSE SYNTHASE5 and CALLOSE SYNTHASE12) and potential callase-related genes (A6 and MYB80), as well as three other putative β-1,3-glucanase genes. Therefore, we propose that the CDM1 gene regulates callose metabolism during microsporogenesis, thereby promoting Arabidopsis male fertility.
authors.affiliation: State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai 200433, China.
authors.forename: Pingli
authors.initials: P
authors.lastname: Lu
authors.forename: Maofeng
authors.initials: M
authors.lastname: Chai
authors.forename: Jiange
authors.initials: J
authors.lastname: Yang
authors.forename: Gang
authors.initials: G
authors.lastname: Ning
authors.forename: Guoliang
authors.initials: G
authors.lastname: Wang
authors.forename: Hong
authors.initials: H
authors.lastname: Ma
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000502:physiology* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D048749:Cytokinesis; D015536:Down-Regulation / Q000235:genetics; D005298:Fertility / Q000235:genetics; D056130:Gametogenesis, Plant / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D043326:Glucan 1,3-beta-Glucosidase / Q000235:genetics / Q000378:metabolism; D005936:Glucans / Q000378:metabolism*; D008540:Meiosis; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D051479:Plant Infertility / Q000235:genetics; D030821:Plants, Genetically Modified; D011058:Pollen / Q000166:cytology / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D013194:Staining and Labeling
chemical_list: D029681:Arabidopsis Proteins; C000593209:CDM1 protein, Arabidopsis; D005936:Glucans; C048306:callose; D043326:Glucan 1,3-beta-Glucosidase