An improved method for transformation of lettuce by Agrobacterium tumefaciens with a gene that confers freezing resistance
An improved method for transformation of lettuce by Agrobacterium tumefaciens with a gene that confers freezing resistance
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DOI：
10.1590/s1516-89132001000200013
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发表时间：
2001
影响因子：
1
通讯作者：
Marcos Pileggi;A. Pereira;Joandrei dos Santos Silva;S. A. Pileggi;D. Verma
中科院分区：
文献类型：
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作者：
Marcos Pileggi;A. Pereira;Joandrei dos Santos Silva;S. A. Pileggi;D. Verma
Torres等（1993）描述了一种利用农杆菌构建转基因生菜品种的有效方法。在本工作中，描述了上述过程的改进，并应用于用突变的P5CS基因转化大急流。主要的修改是将转换和再生协议变得更加实用。并通过增加外植体损伤面积和延长与农杆菌共培养时间（提高培养浓度）来改进转化步骤。对未转化的植物和细菌施加更大的选择压力。在这些工作中，我们关注的是获得T1和T2种子。P5CS基因编码d1 -吡啶-5-羧酸合成酶，这是一种双功能酶，可催化植物中脯氨酸的两步生物合成（Zhang et al., 1995; Peng et al., 1996），而突变基因对脯氨酸的反馈抑制不敏感。这种基因的潜在好处是，由于细胞内脯氨酸水平的增加，使其具有抗水胁迫（干旱、盐、冷）的能力，脯氨酸就像一种渗透保护剂。本工作可以获得并鉴定抗冷冻温度的转基因生菜品系。
An efficient method for constructing transgenic lettuce cultivars by Agrobacterium tumefaciens was described by Torres et al., 1993. In the present work, an improvement of the above procedure is described and applied to transform the cultivar Grand Rapids with a mutated P5CS gene. The major modifications were concerned with turning more practical the transformation and regeneration protocols. Also we tried to improve transformation steps by increasing injured area in explants and prolonging co-cultivation with Agrobacteria (in larger concentration). A more significant selective pressure was used against non-transformed plants and bacteria. In these work we were concerned to obtain T1 and T2 seeds. The P5CS gene codes for a D1-pyrroline-5-carboxylate synthetase, a bifunctional enzyme that catalyzes two steps of proline biosynthesis in plants (Zhang et al., 1995; Peng et al., 1996), while the mutated gene is insensitive to feedback inhibition by proline. The potential benefit of this gene is to confer water stress resistance (drought, salt, cold) due to increased intracellular levels of proline that works like an osmoprotectant. In this work could obtain and characterize transgenic lettuce lineages which are resistant to freezing temperature.