盐渍化土壤宁夏枸杞甜菜碱对氮素的响应机制研究

Ningxia Lycium barbarum L. is an important resource of medicinal plants in China. Betaine is one of the main active ingredients of Ningxia Lycium barbarum L. which grows in the salinity soil. Nitrogen is also an key factor of fertility in salinity soil. Therofore, it is significance to do .further research on nitrogen response mechanism of betaine in Lycium Barbarum L. in the salinity soil. The research resluts at home and abroad and the group’s preliminary research consistently show that betaine content in Lycium barbarum L. has relevance with nitrogen rate in the salinity soil. However, it is not clear that the relations between betaine and key enzyme metabolism in Lycium barbarum L. and nitrogen. Under nitrogen level, expression characteristics of key enzyme gene is also unclear. Based on Ningxia Lycium barbarum L. NO.7 and under different nitrogen levels and ways, this research decides to apply plant physiology, biochemistry, molecular biology and other related technology and methods to do systematical reasearches as following: (1) The relations between different level and application methods of nitrogen and betaine and metabolic key enzyme of Ningxia Lycium barbarum L.; (2) Expressive features of betaine and of key enzymes gene in Ningxia Lycium barbarum L. under appropriate nitrogen rate and application methods. This research clears nitrogen response mechanism of betaine in Lycium barbarum L. in the typical salinity soil and to provide technical supports for high-quality cultivation of Ningxia Lycium barbarum L..

宁夏枸杞是我国重要的药用植物资源。甜菜碱是盐渍化土壤适生作物宁夏枸杞品质的主要有效成分之一，氮素又是盐渍化土壤宁夏枸杞关键肥力因素之一。因此，深入研究盐渍化土壤宁夏枸杞甜菜碱对氮素响应机制意义重大。国内外及课题组前期的研究一致表明，盐渍化土壤上枸杞体内甜菜碱含量与施氮量有一定相关性。但对枸杞体内甜菜碱及其关键酶代谢水平与氮素的关系、适宜氮素水平下关键酶基因表达特征等方面的研究还不清楚。本研究拟以宁杞7号为材料，在不同施氮水平和不同施氮方式下，运用作物栽培学、生物化学及分子生物学相关方法与技术，系统研究：（1）不同施氮量、不同施氮方式与宁夏枸杞体内甜菜碱及代谢关键酶间的关系；（2）适宜施氮量与施氮方式条件下，宁夏枸杞甜菜碱和关键酶基因的表达特征；明确宁夏枸杞在典型盐渍化土壤上体内甜菜碱对氮素的响应机理，为宁夏枸杞品质栽培提供技术支持。

宁夏枸杞是我国重要的药用植物资源。氮素又是盐渍化土壤宁夏枸杞关键肥力因素之一。因此，深入研究盐渍化土壤宁夏枸杞甜菜碱对氮素响应机制意义重大。本研究拟以宁杞7号为材料，在不同施氮水平和不同施氮方式下，运用作物栽培学、生物化学及分子生物学相关方法与技术，系统研究：（1）不同施氮量、不同施氮方式与宁夏枸杞体内甜菜碱及代谢关键酶间的关系；（2）适宜施氮量与施氮方式条件下，宁夏枸杞甜菜碱和关键酶基因的表达特征；明确宁夏枸杞在典型盐渍化土壤上体内甜菜碱对氮素的响应机理，为宁夏枸杞品质栽培提供技术支持。项目经过研究得出了：氮肥的适度后移会相应增加枸杞单加氧酶含量，基肥或后期追氮太多，均不利用枸杞单加氧酶累积；生育期内适度均匀施氮，利于枸杞甜菜碱醛脱氢酶（BADH）积累；甜菜碱含量与不同时期施氮量有直接关系，不同时期施氮较高时甜菜碱含量较高枸杞产量以氮肥基追比例2:1：1为宜；施氮量在30 kg/666.7m2水平下枸杞果实中各指标达到最大值，其中甜菜碱含量达2.90mg∙kg-1，甜菜碱醛脱氢酶活性达3.71ng/100ug，单加氧酶活性达4.36 ng/100ug，再增加氮肥施用量反而会使各指标下降。通过对不同试验处理进行基因转录组分析，得出枸杞果实甜菜碱合成相关基因在不同处理间存在差异。其中参与甜菜碱合成途径的差异表达基因分别为：126个、55、54个、56个、56个、53个、61个、62个、73个、58个、73个、66个。该研究成果对宁夏枸枸杞的品质化栽培具有重要意义。