Poster: Salinity

Abs # 161: Characterization of salt stress-responsive cDNA clones isolated from the halophyte sea aster （Aster tripolium Ｌ．）using a cDNA macroarray of Arabidopsis thaliana.

Presenter:	Takeda, Migiwa , 991d860n@y01.kobe-u.ac.jp
Authors	Takeda, Migiwa  (A)   Kuwata, Chikara  (D) (C)  Uno, Yuichi  (B)   Shibata, Daisuke  (C)   Kanechi, Michio  (A)   Inagaki, Noboru  (A)
Affiliations:	(A): The Graduate School of Science and Technology, Kobe University (B): Faculty of Agriculture, Kobe University (C): Kazusa DNA Reserch Institute (D): Chiba Prefectual Agruculture Recerch Center

Salt stress is one of the most severe effect on the productivity of plants by both toxicity of some ions and dehydration similar to osmotic stress. The halophytes actually growing in saline environment have strong salt tolerance and compensated for such conditions at morphological and physiological levels. The sea aster (Aster tolipolium L.) is a halophyte that grows in brackishwater. The growth of this plant is not inhibited by 150 mM NaCl, and can survive in 400 mM NaCl. We isolated and characterized nine cDNA clones, which are differentially expressed in sea aster seedlings treated with 400 mM NaCl using a differential screening. In order to obtain the information on salt-responsive genes in sea asters in more detail, we screened cDNA clones of sea asters for NaCl responsiveness using a cDNA macroarray of Arabidopsis thaliana. Hybridization to the filters of Arabidopsis was achieved using α-³³P-labeled single-strand cDNAs synthesized from mRNAs obtained from 400 mM NaCl treated and untreated sea asters seedlings. The data analysis of the duplicated experiments identified 17 cDNA clones whose mRNA levels were changed by more than twice in response to NaCl. Three of them were the same clones as what were obtained by the differential screening method. We compared the character and the difference in expression of these genes under the NaCl stress between Arabidopsis and sea aster.