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核基质结合区(matrix attachment region,MAR)的应用是提高植物基因转化和表达效率的有效方法之一。将烟草(Nicotiana tabacum)核基质结合区TM2构建在植物表达载体pBI121上报告基因GUSA表达盒和选择标记基因NPTII表达盒的两侧翼,利用农杆菌介导的子叶浸染转化番茄(Lycopersicon esculentum)。结果表明,MAR序列能够显著提高转基因植株的转化效率和转基因的表达水平。不同长度的CaMV35S启动子比较表明,TM2的调控活性依赖于启动子的存在,并且具有一定的功能重叠。热诱导型启动子的研究表明,TM2仅提高热诱导的表达强度,而不改变启动子的热诱导表达调控特性。TM2的表达调控特性符合转基因的表达要求,该MAR序列可广泛应用于各种植物的基因工程中。
The application of matrix attachment region (MAR) is one of the effective methods to improve plant gene transformation and expression efficiency. The Nicotiana tabacum nuclear matrix binding region TM2 was constructed on both flanks of the reporter gene GUSA expression cassette and the selectable marker gene NPTII expression cassette on the plant expression vector pBI121 and transformed into Lycopersicon esculentum using Agrobacterium tumefaciens-mediated cotyledon dissection. The results showed that the MAR sequence could significantly improve the transformation efficiency and transgene expression level of transgenic plants. The comparison of CaMV35S promoters with different length shows that the regulatory activity of TM2 depends on the presence of promoters and has certain overlapping functions. Studies of heat-inducible promoters show that TM2 only increases heat-induced expression intensity without altering the heat-inducible expression regulation of the promoter. TM2 expression and regulation characteristics in line with the expression of transgene, the MAR sequence can be widely used in a variety of plant genetic engineering.