Abstract:

In order to elucidate the influence of deficient phosphorus stress on tobacco glucose metabolism and nutrition uptake, Shapei test was designed  with T1 (1 mmol/L Pi) and T2 (0.1 mmol/L Pi) treatments taking Yunyan 87 as experiment material. The contents of sugar, starch, nutritional elements at different parts of tobacco plant, and the activities of sugar metabolism related enzymes were detected under deficient phosphorus stress. Besides, the key sugar metabolism genes (SUT1, INV, AGPase) and the expression differences of high affinity nutrients transport protein family genes (PT1, PT2, HAK1, IRT1) were also analyzed. The results showed that starch and sugar contents increased remarkably in roots and above\|ground parts under Pi deficiency condition. Under deficient phosphorus stress the contents of K and Fe increased  in tobaco roots and above\|ground parts, Mg content reduced. But there was not much difference in Ca content. K and Fe accumulation might be caused by the increase   quantity of high affinity potassium transporters (HAK1) and Iron regulate transporter genes (IRT1). This study has provided theoretical basis for studying the interaction between phosphorus and other nutrient elements in plants.

Key words: tobacco, phosphorus stress, glucose metabolism, nutrient elements

摘要：

为了探明低磷胁迫对烟草糖代谢及养分吸收的影响机理。以云烟87为试材，设置正常供磷（T1,1 mmol/L Pi）和低磷（T2，0.1 mmol/L Pi）两个处理的沙培试验，检测低磷胁迫下烟株不同部位的蔗糖、淀粉、营养元素的含量及糖代谢相关酶的活性，分析糖代谢关键基因（SUT1、INV、AGPase）及高亲和营养元素转运蛋白家族基因（PT1、PT2、HAK1、IRT1）的表达差异。结果表明：①低磷胁迫显著增加了烟株根部和地上部的蔗糖含量；虽然焦磷酸化酶（AGPase）基因在低磷条件下表达量下调，但是由于淀粉酶活性被强烈抑制，淀粉含量仍显著增加；②低磷胁迫增加了烟株根部和地上部K和Fe的含量，降低了Mg的含量，Ca含量差异不显著；K和Fe的积累可能是由高亲和钾转运蛋白（HAK1）及铁调控转运体基因（IRT1）的表达量提高引起的，为磷与其他营养元素之间的互作提供理论基础。

关键词: 烟草；磷胁迫；糖代谢；营养元素