盐渍化土壤对于多数植物最大的伤害在于Na+浓度过高，Na+作为一种主要的有害离子会抑制植物的生长。植物的盐耐受是许多不同机制共同参与的过程，可以通过调节细胞信号系统而使诸多因素有效协调，或诱导大量基因的转录，从而提高植物的耐盐性。钙调磷酸酶（Calcineurin, CN）是一种依赖于Ca2+/CaM的蛋白磷酸酶（Phosphatase 2B, PP2B）。在酵母细胞中，CN通过调节Na+的内流和外排参与盐胁迫信号传导，从而影响酵母对盐的耐受。而将酵母细胞CN的催化亚基CNA截短体和调节亚基CNB在烟草中共表达，一些表现CN活性的转基因烟草植株的耐盐性得到了提高。这暗示出，与在酵母中相似，CN在植物中参与了一条与植物盐适应有关的信号调节通路。另外，在植物中发现的两类CNB的类似物SOS3和AtCBL在拟南芥的盐耐受中也发挥重要作用。 本实验是在前人研究的基础上，对转CNB基因的烟草及其子一代（T1）进行了分子方面的鉴定和耐盐性检测。30株筛选得到的转基因烟草经PCR、Southern Blotting鉴定证实CNB基因已经成功整合到植物基因组中；而RT-PCR、蛋白免疫印迹（Westren Blot）的结果表明CNB基因在转基因植株中已经表达。耐盐性的测定表明，转基因烟草植株的盐耐受能力有较大提高。严格自交所得的T1代的分析表明，检测的两个转基因株系后代遵循孟德尔分离规律，同时T1代转基因烟草的耐盐能力也有较大提高。 本文将CNB基因转入“中蔬5号”番茄中，以期获得高耐盐能力的番茄。目前已经获得了再生植株，转基因植株的筛选和其它检测正在进行中。

Among the most common effects of soil salinity is growth inhibition by Na+. Tolerance to salinity involves processes in many different parts of the plant, the capacity to effect coordinate control of several effectors through the modulation of signal-regulatory cascades or transcriptional activation of multiple genes may have the greatest impact on salt tolerance. Calcineurin (CaN) is a Ca2+- and calmodulin-dependent protein phosphatase (PP2B) that, in yeast, is an integral intermediate of a salt-stress signal transduction pathway that effects NaCl tolerance through the regulation of Na+ influx and efflux. A truncated form of CNA and CNB of yeast CN were coexpressed in transgenic tobacoo plants. Several different transgenic lines that expressed activated CN also exhibited substantial NaCl tolerance. This results indicate that in plants, like in yeast, a Ca2+ and calmodulin-dependent CN signal pathway regulates determinants of salt tolerance required for stress adaptation. In plants, calcineurin B-like proteins AtCBL4 or Salt Overly Sensitive 3 (SOS3) has been shown to play a role in salt resistance of Arabidopsis.Calcineurin B subunit (CNB) gene was transferred into tobacco (Nicotiana tabacum K326) by Agrobacterium-mediated transformation. Thirty kanamycin-resistant shoots were selectived in selective medium (MSo+1mg/L6-BA+30g/L sucrose+0.1mg/L IAA+200g/ml Kan). PCR and Southern Blotting analysis showed that the CNB gene was integrated into genome of tobacco. RT-PCR and Western Blot assay indicated that the CNB was expressed in transgenic tobacco. Salt tolerance evaluation of the tobaccos were performed and showing that the capacity for salt tolerance of transformants lines were enhanced obviously. Transgenic T1 progenies were obtained by strict self-pollination in controlled condition and were used for progeny analysis. Test of kanamycin tolerance of T1 seedlings demonstrated that the tolerant and sensitive progenies fit a 3:1 segregation ratio. Germination ratio and growth status of the transgenic progenies were improved significantly under salt stress.The CNB gene was introduced to tomato (ZhongShu 5#) via Agrobacterium-mediated transformation in order to obtain salt-tolerant transgenic tomato. Filtration and molecular examinations of regeneration shoots are now in process.