35th NPS abstract book

P15
How has our understanding of the conifer sexual reproductive process
advanced in the age of genomics?
D.D. FERNANDO
Department of Environmental and Forest Biology, State University of New York College of
Environmental Science and Forestry, One Forestry Drive, Syracuse, NY 13210, USA
The long generation time and lengthy reproductive process in conifers are major barriers to
functional genomics and genetic improvement. Therefore, our understanding of conifer sexual
reproduction has also been mostly confined to comparative evolutionary genomics. This approach
has provided insights on the divergence of sequences related to angiosperm genes involved in
flowering time and floral organ identities, embryo formation, and other genes expressed in the
sporophyte phase of the reproductive stage. My lab is focused on the analysis of genes expressed in
the haploid phase of the reproductive stage, particularly male gametophyte development. We have
identified and characterized genes using various genomic and proteomic approaches including
microRNA analysis. We have described several conserved miRNAs in mature and germinated loblolly
pine pollen and many of these are differentially expressed indicating that male gametophyte
development is regulated at the miRNA level. This presentation/poster will focus on some of our
unpublished results on the correlation between conserved miRNA genes and their respective target
sequences. We have also introduced novel miRNA genes into pollen tubes through Agrobacterium
transformation and interesting phenotypes were obtained. We are developing a microgenomic
approach to validate transformed pollen tubes. The main goal of my lab is to understand the
molecular mechanism underlying conifer pollen germination which is necessary to be able to
facilitate germination and tube growth so as we may be able to bypass incompatibility barriers and
thus create novel hybrids or prevent germination as a gene containment strategy.
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