| Abstract Detail
Reproductive Development Huang, Yiding [1], Palanivelu, Ravishankar [2]. Female gametophytic mutant impaired in final stages of pollen tube guidance. Pollen tube growth and guidance initiates after pollen grain hydrates on the papillar cells of stigma. Subsequently, pollen tube is guided along the transmission tissue, the funiculus and then into the ovule micropyle. After entering the ovule, pollen tube terminates its journey within the synergid cell. Seeds are not produced if any aspect of this pollen tube guidance process is disrupted. Although some of the factors affecting pollen tube growth and guidance have been identified, many aspects of pollen tube guidance still remain unclear. Arabidopsis female gametophytic mutants defective in pollen tube growth and guidance are ideal tools to unravel the mechanisms that regulate pollen tube guidance to embryo sacs. For this purpose, we screened Arabidopsis plants with reduced seed containing siliques from among the SALK TDNA insertion collection and identified a reduced fertile mutant (ref1, average seed number 22.54±5.75 compared to 56.17±3.37 in wild type). Based on the progeny analyses and reciprocal crosses to wild type plants, it was found that ref1 caused female gameotphytic defects. To identify the pollen tube growth stage that is defective in ref1, we pollinated mutant pistils with Lat52:GUS pollen and monitored the GUS activity. These experiments demonstrated that pollen tube germination and growth in mutant stigma, style and ovary were comparable to pollen tube behavior on a wild type pistil. However, even wild type pollen tubes exhibited abnormal and excessive growth after entering the mutant ovules. Real-time observations of pollen tube interactions with ref1 mutant ovules in an in vitro guidance assay also revealed that fertilized ref1 ovules were defective in deflecting additional pollen tubes. Progress on microscopy analyses of ref1 mutant phenotypes and cloning the gene disrupted in ref1 will be reported.
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1 - University of Arizona, Department of Plant Sciences, 1140 E South Campus Dr, Tucson, AZ, 85721, USA
2 - University of Arizona, Department of Plant Sciences
Keywords:
Female gametophytic mutant
pollen tube guidance.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P28056
Abstract ID:2259 |
