EdHP1(氢离子焦磷酸化酶)基因小麦的钾利用特征研究*

Potassium utilization in EdHP1 (H+-pyrophosphatase) transgenic wheat

  • 摘要: 由于农业生产对地力的掠夺加剧了土壤的钾素亏缺, 严重影响了农业的可持续发展。本文通过根箱试验对比研究K0(不施钾)、K1(施KCl 186 kg·hm-2)和K2(施KCl 805 kg·hm-2)3个施钾水平下, 转披碱草EdHP1(氢离子焦磷酸化酶)基因小麦和野生型小麦根系对土壤钾的吸收利用、根际钾素动态及土壤酶活性等的影响, 探讨转基因技术对提高小麦钾素的吸收和利用效率的潜力。结果表明: 在不同施钾水平下, 转基因小麦根际土壤速效钾含量均低于野生型小麦。在K1施钾水平下, 转基因小麦根际土壤速效钾含量比野生型小麦分别低8.30%(30 d)、15.02%(60 d)和12.53%(75 d)。由于转基因小麦对根际土壤钾的吸收较大, 导致在试验中有非根际土壤速效钾向根际迁移的过程。在K0、K1和K2钾水平下, 转基因小麦钾生物利用指数比野生型小麦分别提高了22.39%、136.21%和14.03%, 地上部钾含量分别提高了225.97%、18.77%和17.28%, 根系阳离子交换量(CEC)分别提高了55.19%、33.16%和30.44%。不同钾水平下的转基因小麦根际土壤过氧化氢酶和脲酶活性均显著高于野生型小麦。因此, 披碱草根系EdHP1基因的引入, 能有效提高根系阳离子交换量, 创造适于钾吸收的根际环境, 显著提高了小麦对钾素的吸收和利用效率。

     

    Abstract: With intensive land farming, soil potassium deficiency has become increasingly serious, limiting sustainable agricultural development. In this study, the differences between EdHP1 (H+-pyrophosphatase) transgenic and wild wheat were investigated in terms of potassium absorption and utilization, rhizosphere soil potassium dynamic and soil enzyme activities. The research aimed to determine the potentials of transgenic technologies in promoting wheat potassium absorption and utilization. The results showed that available K in rhizosphere of transgenic wheat was significantly lower than that of wild wheat at different K-levels. Available K in rhizosphere of transgenic wheat were 8.30% (30 d), 15.02% (60 d) and 12.53% (75 d) below those of wild wheat for K1-level (KCl application rate of 186 kg·hm-2). For transgenic wheat high potassium absorption, available K is transported from non-rhizosphere to rhizosphere soil. Under K0 (no KCl), K1 and K2 (KCl application rate of 805 kg·hm-2) treatments, biomass K use efficiencies (KUI-B) were 22.39%, 136.21% and 14.03%, respectively. Also while shoot K contents were 225.97%, 18.77% and 17.28%, root cation exchange capacities (CEC) were 55.19%, 33.16% and 30.44%, respectively. Rhizosphere soil catalase and urease activities of transgenic wheat were significantly higher than those of wild wheat at different K-levels. Thus transgenic technology improved root CEC and created good rhizosphere environment for efficient wheat potassium absorption and utilization.

     

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