Male reproductive processes in flowering plants take place in the stamen (Esau, 1977). This sporophytic organ system contains diploid cells that undergo meiosis and produce haploid male spores, or microspores. Microspores divide mitotically and differentiate into multicellular male gametophytes, or pollen grains, that contain the sperm cells. Figures 1 and 2 show that the stamen consists of two...

Whole-genome duplication through the formation of diploid gametes is a major route for polyploidization, speciation, and diversification in plants. The prevalence of polyploids in adverse climates led us to hypothesize that abiotic stress conditions can induce or stimulate diploid gamete production. In this study, we show that short periods of cold stress induce the production of diploid and po...

Sweepoviruses have been identified globally and cause substantial yield losses and cultivar decline in sweet potato. This study aimed to investigate the interaction between sweepovirus and plant host by analyzing the function of the viral protein C4 of Sweet potato leaf curl virus-Jiangsu (SPLCV-JS), a sweepovirus cloned from diseased sweet potato plants in East China. Ectopic expression of the...

Arabidopsis thaliana MYB80 (formerly MYB103) is expressed in the tapetum and microspores between anther developmental stages 6 and 10. MYB80 encodes a MYB transcription factor that is essential for tapetal and pollen development. Using microarray analysis of anther mRNA, we identified 404 genes differentially expressed in the myb80 mutant. Employing the glucocorticoid receptor system, the expre...

The pollen cell wall is important for protection of male sperm from physical stresses and consists of an inner gametophytederived intine layer and a sporophyte-derived exine layer. The polymeric constituents of the robust exine are termed sporopollenin. The mechanisms by which sporopollenin is anchored onto microspores and polymerized in specific patterns are unknown, but the primexine, a trans...

The anther, pollen and ovule development in Achillea tenuifolia were studied with a bright field microscopy. Results showed that the anther is of tetrasporangiate type and the anther wall is composed by four layers: an epidermis, an endothecium, one middle layer and a tapetum layer. Tapetum is of secretory type and its cells showed polyploidy. Pollen tetrads were tetrahedral, microspores were v...

Microsporogenesis in angiosperms takes places within the anther. Microspores are surrounded by a layer of cells, the tapetum, which degenerates during the later stages of pollen development with cytological features characteristic of programmed cell death (PCD). We report herein that the expression of AtBI-1, which suppresses Bax-induced cell death, in the tapetum at the tetrad stage inhibits t...

Arabidopsis thaliana MYB80 (formerly MYB103) is expressed in the tapetum and microspores between anther developmental stages 6 and 10. MYB80 encodes a MYB transcription factor that is essential for tapetal and pollen development. Using microarray analysis of anther mRNA, we identified 404 genes differentially expressed in the myb80 mutant. Employing the glucocorticoid receptor system, the expre...

Mutations in the QUARTET loci in Arabidopsis result in failure of microspore separation during pollen development due to a defect in degradation of the pollen mother cell wall during late stages of pollen development. Mutations in a new locus required for microspore separation, QRT3, were isolated, and the corresponding gene was cloned by T-DNA tagging. QRT3 encodes a protein that is approximat...

To investigate the regulation of gene expression during male gametophyte development, we analyzed the promoter activity of two different genes (LAT52 and LAT59) from tomato, isolated on the basis of their anther-specific expression. In transgenic tomato, tobacco and Arabidopsis plants containing the LAT52 promoter region fused to the beta-glucuronidase (GUS) gene, GUS activity was restricted to...