AtNHX1基因对荞麦的遗传转化及抗盐再生植株的获得

通过农杆菌介导法将拟南芥液泡膜Na⁺/H⁺反向转运蛋白基因AtNHX1转入荞麦中，在2.0mg/L 6-BA、0.1mg/L IAA、1mg/L KT、50mg/L卡那霉素和500mg/L头孢霉素的MS培养基上进行选择培养，从来源于864块外植体的36块抗性愈伤组织中共获得426棵再生植株（转化频率为4.17%）。经PCR、Southern印迹分析、RT-PCR和Northern检测，初步证实AtNHX1基因已整合至荞麦基因组中。用200mmol/L的盐水对转基因植株和对照植株进行胁迫处理6周，转基因植株能够生存，而对照植株死亡。用不同浓度的NaCl溶液处理转基因植株和对照植株，发现Na⁺及脯氨酸含量在转基因植株中的积累水平显著高于对照植株，而K⁺的含量在转基因植株中的积累水平低于对照植株。次生代谢产物黄酮类化合物芦丁在转基因植株根、茎和叶片中的含量也比对照植株明显要高。这些结果表明利用基因工程手段提高作物的耐盐性是可行的。

Genetic Transformation of Buckwheat (Fagopyrum esculentum Moench) with AtNHX1 Gene and Regeneration of Salt-tolerant Transgenic Plants

The Arabidopsis thaliana tonoplast Na⁺/H⁺ antiporter gene, AtNHX1, was transferred into buckwheat by Agrobacterium-mediated method. Transgenic buckwheat plants were regenerated and selected on MS basal medium supplemented with 2.0mg/L 6-BA, 1.0mg/L KT, 0.1mg/L IAA, 50mg/L kanamycin and 500mg/L carbenicillin. 426 seedlings from 36 resistant calli originated from 864 explants (transformed about at 4.17 percentage) exhibited resistance to kanamycin. The transformants were confirmed by PCR, Southern blotting, RT-PCR and Northern blotting analysis. After stress treatment for 6 weeks with 200mmol/L NaCl, transgenic plants survived, while wild-type plants did not. After 3 days of stress treatment through different concentrations of NaCl, transgenic plants accumulated higher concentration of Na⁺ and proline than the control plants. However, the K⁺ concentration of transgenic plants declined in comparison with the control plants. Moreover, the rutin content of the roots, stems and leaves of transgenic buckwheat increased than those of the control plants. These results showed that it could be possible to improve the salt-tolerance of crops with genetic technology.