| Abstract Detail
Growth and Vegetative Development Oh, Thomas [1], Wartell, Roger [2], Cairney, John [3], Pullman, Gerald [3]. MicroRNA (miRNA) regulation of gene expression differs in Embryo and Female Gametophyte tissues during Embryogenesis of Loblolly Pine (Pinus taeda). In this work we have identified the presence of five (5) miRNAs during embryogenesis of a gymnosperm Loblolly pine (LP, Pinus taeda) and examined their activity. LP provides an advantage in studies of embryogenesis relative to angiosperms due to the relatively large size of its embryos that permit isolation of a series of developmental stages. Evidence for miRNAs in both somatic embryo and female gametophyte (FG) tissues was obtained using Northern analysis and quantitative real-time reverse transcription polymerase chain reactions (qRT-PCR) mediated with E. coli poly A polymerase (PAP). We also examined the expression of messenger RNAs (mRNAs) that are potential targets for specific miRNAs as a function of the stage of embryo development. Regional Amplification PCR (RA-PCR) was employed to quantify 3 segments of the mRNAs; a 5’ segment, a 3’ segment, and a middle segment that contained the site complimentary to the miRNA. Our results are consistent with developmentally regulated miR167-mediated cleavage of target mRNA, Auxin Response Factor 8-Like (ARF8L) in embryos. Using qRT-PCR a reciprocal relationship was suggested between the quantity of a miR167 and its target ARF8L mRNA during development. In addition, we note that different patterns of ARF8L regulation are observed in embryo vs. FG and components involved in miRNA-directed regulation appear to be absent in FG. These findings open new opportunities to investigate function of regulatory miRNAs expressed in the FG. Since FG tissue is absent in the somatic embryogenesis system, an understanding of the role of FG in regulation of embryo development may lead to advancements in clonal technology for improved sustainable forest productivity. Log in to add this item to your schedule
1 - Institute of Paper Science and Technology (IPST) at Georgia Tech, Forest Biology, 500 10th St. NW, Atlanta, GA, 30332, USA 2 - Georgia Tech, Biology 3 - Georgia Tech, IPST and Biology
Keywords: Loblolly pine Pinus taeda embryogenesis microRNA miRNA zygotic embryo somatic embryo female gametophyte megagametophyte development regional amplification PCR RA-PCR auxin response factor 8-like ARF8L qRT-PCR Argonaute forest.
Presentation Type: Plant Biology Abstract Session: P Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton Date: Sunday, July 8th, 2007 Time: 8:00 AM Number: P26011 Abstract ID:240 |