Expression Pattern of Plasma Membrane Water Channel Genes from Seedlings of Panax ginseng C. A. Mey. in Response to Salinity Stress
Background : Water uptake and flow across cellular membranes is a fundamental requirement for plant growth and development, and plant water status is important not only for plant growth under favorable conditions but also for ability of a plant to tolerate adverse environmental conditions. Thus identification of plasma membrane water channel genes (aquaporins) in ginseng provides extensive information for functional studies and the development of markers for salinity stress tolerance. Methods and Results : For salinity treatment, the plants were grown for 4 weeks in culture medium gelled with 0.8% Phytoagar, and the old media were replaced with the fresh medium containing NaCl at 0, 50, 100, 200 and 400 mM, respectively. The samples for stress treated and non-stressed plants were collected from 6h to 72h, and frozen immediately into liquid nitrogen. According to the sequence information from the assembled transcripts, four primer pairs were designed from the aquaporin gene regions. In order to determine the pattern of aquaporins expression in ginseng seedlings to salinity stress, we conducted semi-quantitative RT-PCR. Conclusion : A tonoplast intrinsic protein 1 (TIP1)-type aquaporin is not only believed to be essential for plant life, but also to be beneficial for growth under salinity stress. Therefore, a deeper understanding of aquaporin genes in ginseng will be essential for crop improvement, which could help us to understand the molecular genetic basis for the ginseng genetic improvement and also provide the functional genetic resources for selective breeding and transgenic research.