| Abiotic stresses such as drought, low temperature, and high salinity are major environmental factors that dramatically limit plant growth and crop productivity. The prediction is that high salinity will continue to be the major single abiotic factor likely to affect crop yields globally. High concentration of salinity disrupts the homeostasis in ion distribution and water potential, results in osmotic stress and further leads to the damage on various molecules, such as protein, nucleotide acid etc. It can arose growth arrest, and in some extreme conditions, even death of plants. Osmotic stress tolerance requires that water flux is regulated. A major problem encountered by plants during a period of water deficit is the maintenance of cell turgor. Most of the adaptations to such conditions involve mechanisms limiting water loss. Such mechanisms, which regulate water flux, are likely to be mediated, in part, by aquaponns. Aquaponns are integral membrane proteins occurring in mammals, plants, and microorganisms, which serve as channels that permit the bidirectional passage of water through cellular membranes. The rate of transmembrane water flux may be controlled by changing the abundance or the activity of the aquaponns.S. salsa is an euhalophyte with succulent leaves that can survive under seawater-level salinity. It has formed some specific mechanisms in salinity tolerance during the evolution. Previously, we have constructed a 400mmol/L NaCl-treated cDNA library of S. salsa and acquired 1000 ESTs (Expressed Sequence Tags) by the large-scale partial sequencing of randomly selected cDNA clones. In this research, we isolated a cDNA that maybe encode an aquaporin (S. salsa Plasma membrane Intrinsic Protein, SsPIP, BF023789) located in plasma membrane of S. salsa. Then we analyzed the sequence characterizations, genomic structures and transcriptional levels under salinity stress. We found SsPIP has high homologous with AcPIP (Atriplex canescens Plasma membrane Intrinsic Protein, AcPIP). Southern blot analysis showed that there was only one copy of SsPIP in the S. salsa genome. Northern blot analysis indicated that the expression level of SsPIP in 5. salsa roots was significantly higher than that in leaves and shoots after being treated with 400mmol/L NaCl for 72h. And we also concluded that the transcriptional level of SsPIP in S. salsa leaves was increased after being treated with 400 mmol/L NaCl for 4d and 6d respectively.Transformation of soybean has been far from routine. The first two reports of soybean transformation used two very different methods to transform soybean: Hinchee et al (1988) used Agrobacterium-mediated transformation of cotyledonary nodes while McCabe et al (1988) used particle bombardment of shoot meristems. Soybean transformation reports following these initial papers have been limited and the transformation efficiency of soybean has remained low, the reason is that cells that are regeneration-competent must also be accessible and transformation-competent. Transformation will not be successful if either transformation or regeneration is inefficient, or if transformation and regeneration are "uncoupled". Knowledge of both processes and the ability to bring them together will result in recovery of transgenics. Now there are several methods to genetically transform plants, such as Agrobacterium-mediated transformation of excised plant tissues, particle bombardnent, electroporation, Sonication-assisted Agrobacterium-medialed transformation, liposome-medi -ated transformation and in planta Agrobacterium-mediated transformation via vacuun infiltration of whole plants. The first two methods are the most commonly used for soybean transformation. The other methods have not been optimized for soybean, and are therefore less efficient and not often used.Previously, we isolated SsNHXl (encoding a vacuolar Na+/H+ antiporter) from S. salsa, and further research was done through the overexpression in Arabidopsis thaliana, it could help us to elucidate the salt tolerance of halophyte. We con...
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