^(15)NO_(2)胁迫下三角梅不同器官的氮素吸收分配动态及代谢规律

Dynamics and metabolism of nitrogen absorption and distribution in different organs of Bougainvillea spectabilis under^(15)NO_(2)stress

近年来研究园林植物消减大气污染物的修复技术及其原理,理清氮氧化物污染对植物生理生态的影响机制,对城市生态环境保护和文明建设具有重要意义。以三角梅(Bougainvillea spectabilis Willd)小苗为研究材料,通过人工模拟熏气法,设计短时间高浓度^(15)NO_(2)胁迫处理,以CK为对照,比较8.0μL/L^(15)NO_(2)处理和4.0μL/L^(15)NO_(2)处理对三角梅各器官^(15)N的吸收量和各器官^(15)N-氨基酸含量的影响,探究^(15)NO_(2)胁迫下三角梅各器官内氮素的吸收分配动态及代谢规律研究。结果表明,^(15)NO_(2)胁迫后显著提高了三角梅各器官^(15)N含量,其中叶片是^(15)N的主要积累器官。8.0μL/L^(15)NO_(2)处理下三角梅各器官^(15)N含量、^(15)N-硝态氮含量较4.0μL/L^(15)NO_(2)和0μL/L^(15)NO_(2)均极显著上升,^(15)N-铵态氮含量较4.0μL/L^(15)NO_(2)除在叶中极显著下降了54.0%外,其余均极显著上升;^(15)N含量在三角梅各器官中分配差异显著,4.0μL/L^(15)NO_(2)处理下总体趋势为叶>根>茎。随着^(15)NO_(2)浓度不断上升,4.0μL/L^(15)NO_(2)处理下三角梅各器官中^(15)N-氨基酸含量均呈上升趋势,分配率均表现为叶>根>茎;8.0μL/L^(15)NO_(2)处理下各器官中^(15)N-氨基酸含量则未呈现统一的变化趋势,与4.0μL/L^(15)NO_(2)相比,各器官中部分^(15)N-氨基酸含量呈下降趋势。因此,不同浓度^(15)NO_(2)胁迫后,三角梅各器官对^(15)N的吸收量和各器官^(15)N-氨基酸合成量变化不一,4.0μL/L^(15)NO_(2)胁迫对植物的^(15)N的吸收量和各器官^(15)N-氨基酸含量均呈现为上升趋势,叶片为^(15)N和^(15)N-氨基酸积累的主要器官;8.0μL/L^(15)NO_(2)胁迫抑制植物根系的^(15)N分配,促进叶和茎的^(15)N分配,叶片为^(15)N积累的主要器官。该研究结果为氮氧化物污染在植物体内的迁移转化规律提供一定的理论依据。

In recent years,it is of great significance for urban ecological environment protection and civilization construction to study the remediation technology and principle of garden plants to reduce air pollutants and clarify the effect mechanism of nitrogen oxide pollution on plant physiology and ecology.In this paper,Bougainvillea spectabilis Willd seedlings were taken as the research object.We designed a short time high concentration of^(15)NO_(2)stress treatment by artificial fumigation.Taking CK as control,the effects of 8.0μL/L^(15)NO_(2)treatment and 4.0μL/L^(15)NO_(2)treatment on ^(15) uptake and ^(15)-amino acid content in various organs of B.spectabilis were compared in order to summarize the dynamics and metabolism of nitrogen absorption and distribution in various organs of B.spectabilis under ^(15) O_(2) stress.The results showed that ^(15) O_(2) stress significantly increased the ^(15)-nitrogen content in all organs of B.spectabilis,and the leaf was the main accumulation organ of ^(15)-nitrogen.Compared with 4.0μL/L and 0μL/L.The contents of ^(15) and ^(15)-nitrate nitrogen in organs were significantly increased under 8.0μL/L treatment.Compared with 4.0μL/L^(15)NO_(2)treatment,the contents of ^(15)-ammonium nitrogen were significantly increased except its content in leaves was significantly decreased by 54.0%.The distribution of nitrogen in different organs of B.spectabilis was significantly different,and the general trend was leaf>root>stems under 4.0μL/L^(15)NO_(2)treatment.With the increasing concentration of^(15)NO_(2),the contents of ^(15)-amino acids in all organs of B.spectabilis under 4.0μL/L^(15)NO_(2)treatment showed an increasing trend,and the distribution rate was leaf>root>stems.Under the treatment of 8.0μL/L,the contents of ^(15)-amino acids in all organs did not show a uniform trend of change,and the contents of some ^(15)-amino acids in all organs showed a downward trend compared with that of 4.0μL/L.Therefore,after different concentrations of^(15)NO_(2)stress,the absorption of ^(15) and the synthesis of ^(15)-amino acid in each organ of B.spectabilis varied.The absorption of ^(15) and the content of ^(15)-amino acid in each organ of B.spectabilis under 4.0μL/L^(15)NO_(2)stress showed an upward trend,and leaves were the main organs of ^(15) and ^(15)-amino acid accumulation.8.0μL/L^(15)NO_(2)stress inhibited^(15) allocation in roots and promoted ^(15) allocation in leaves and stems,with leaves being the main organ for ^(15) accumulation.These results provide a theoretical basis for the migraton and transformation of nitrogen oxide pollution in plants.