Poster: Membrane transport

Abs # 187: Expression and localization studies of LHT amino acid transporters from Arabidopsis thaliana

Presenter:	Foster, Justin j, foster4@mail.wsu.edu
Authors	Foster, Justin j (A)   Lee, Yong-Hwa  (A)   Tegeder, Mechthild  (A)
Affiliations:	(A): Washington State University,School of Biological Science,sCenter for Reproductive Biology,Center for Integrated Biotechnology

Transport of nitrogen in the form of amino acids plays an important role in plant growth and development. With respect to partitioning of amino acids in plants, it is predicted that transporter proteins are necessary for the translocation of the organic nitrogen. We are interested in identifying amino acid transporters and in understanding their function and regulation in planta. The knowledge gained can be used for future research objectives to manipulate partitioning processes and thereby, for example, increase reproductive success. This work is focused on the expression and localization of five members of the AtLHT amino acid transporter family. Organ-specific expression of AtLHTs was resolved by using an RT-PCR approach and RNA from different plant organs of Arabidopsis. The studies showed specific expression patterns for each AtLHT, indicating differences in transporter function. To resolve the localization of expression, promoters of the AtLHTs were isolated, fused to the GUS-gene and transgenic Arabidopsis plants were produced. The promoter-GUS studies showed tissue and cell specific localization of the LHTs. For example, in AtLHT6-promoter-GUS plants staining was detected in the stigma of the pistil during late stages of flower development indicating a role of AtLHT6 in nutrient accumulation for pollen germination. GUS expression was also seen in the transmitting tissue of the pistil where amino acids are needed for pollen tube growth. This work was supported by NSF Grant IBN-0135344, which is greatly appreciated.