Abstract:

In order to obtain homogeneous transgenic line over-expressed AlHAK1 and to identify its salt tolerance, this research carried out PCR amplification and RT-PCR detection on T3 material of AlHAK1 gene, and studied the plant growth vigor, root system morphology parameter, ion content and changes in antioxidant enzyme activity under hydroponic condition. The results showed that AlHAK1 gene had been integrated into the cotton genome and expressed in transgenic lines. Under salt stress condition, the height of transgenic plant was higher than the wild type plant by 16.5% and the difference reached significant level (P＜0.05). Also, the total root length of transgenic plant root system morphology parameter, specific root length and root surface area increased by 62.23%, 40.02% and 29.22%, respectively. While the average root diameter decreased by 22.22%, and the difference reached significant level (P＜0.05). Besides, under salt stress condition the seedling of transgenic plant could maintain higher K+content, lower Na+ content and higher K+/Na+ ratio. The activities of SOD and POD were all higher than that of the wild type plant. These results further indicated that over-expression of exogenous AlHAK1 in cotton had enhanced the salt tolerance of trancegenic cotton, which provided important germplasm resources for breeding new cotton varieties that were adapted to salinity soil.

Key words: potassium transporter transgenic (AlHAK1), cotton (Gossypium hirsutum L.), salt tolerance, root system morphology parameter

摘要：

为了获得超表达獐茅AlHAK1基因棉花纯合系并验证其耐盐能力，对转AlHAK1基因T3代材料进行了PCR与RT-PCR鉴定，并在水培条件下研究了纯合系植株长势、根系形态参数、离子含量和相关抗氧化酶活性变化。结果表明在盐胁迫条件下，转基因植株偏高，较野生型增加了16.5%，同时转基因植株根系形态参数总根长、比根长和根表面积分别增加了62.23%、40.02%和29.22%，而根的平均直径降低了22.22%，均达到了差异显著水平（P<0.05）。此外，在盐胁迫条件下，转基因幼苗能维持根和叶中较高的K+含量，较低的Na+含量和较高的K+/Na+，其超氧化物歧化酶(SOD)和过氧化酶（POD）活性均比野生型植株有所提高。该结果进一步表明供试外源AlHAK1基因在棉花中超表达，提高了转基因棉花耐盐能力，为培育适应盐渍化土壤环境下生长的棉花新品种提供重要的种质资源。

关键词: 钾转运蛋白基因（AlHAK1）；棉花；耐盐性；根系形态参数