Poster: Reproductive development
Abs #
359: Pistil specific transcripts encoding metiltransferases are produced by a complex combination of different exons in tobacco
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Presenter: |
Goldman, Gustavo H., ggoldman@usp.br |
Authors | Molfetta, Jeanne B. (A) daSilva, Idalete (A) Quiapim, Andréa C. (A) Angelo, Paula Cristina S. (A) Ribeiro, Davidson C. D. (B) Goldman, Gustavo H. (B) Goldman, Maria Helena S. (A) | | Affiliations: |
(A): FFCLRP/University of Sao Paulo Department of Biology
(B): FCFRP/University of Sao Paulo Department of Pharmaceutical Sciences
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| Web Site: | http://143.107.203.68/Mhelena/default.html | |
The pistil has a dual function: the production of the female gametophyte and the establishment of pollen-pistil interactions that will determine the fate of the pollen. The objective of our work is to identify genes preferentially expressed in the pistil and to establish their function in plant reproduction. By differential screening of a tobacco stigma/style cDNA library we have identified a pistil-specific cDNA clone (PA3) encoding a protein with high similarity to methyltransferases (SAMT, BAMT and JAMT). Northern blot experiments with RNA extracted from different organs have revealed 4 transcripts exclusively present in the pistil samples. The 4 transcripts are highly expressed in ovaries while in stigmas/styles only 3 transcripts accumulate to high levels. All transcripts are developmentally regulated with expression increasing towards anthesis. To identify the other transcripts, we analyzed the TOBEST database in which we found 14 cDNAs with sequences in common to PA3. Only 2 clones were identical to PA3 and the others contained parts of sequences present in PA3. A genomic clone with a partial PA3 sequence was isolated. After analysis of all sequences, we suggest the 4 transcripts are produced by a complex combination of different exons, probably by alternative splicing. We are isolating other genomic clones to have a complete picture of the gene(s). What is the possible role of pistil-specific methyltransferases? Methyltransferases produce volatile compounds that have important biological roles. It is interesting to speculate about a volatile signal that would establish a communication between a maturing pistil and the surrounding stamens from the same flower, flowers of the same plant or even neighboring plants.
Financial Support: CNPq and FAPESP - BRAZIL
