摘要
【目的】探明施氮对叶片氮同化和叶绿素合成的影响机理。【方法】以5 a生‘太田椪柑’为试材,通过在果实生长发育期连续施氮,定期测定叶绿素含量和光合效率,以及叶片氮同化和叶绿素合成关键酶基因的表达,研究了施氮对太田椪柑叶片氮同化和叶绿素合成中关键酶基因的动态变化。【结果】(1)叶片叶绿素含量及叶片的净光合效率显著地增加;(2)氮同化关键酶基因CrGS2在处理期间相比于对照持续高量表达,CrNADH-GOGAT、CrGOGAT在处理后30 d大幅度过量表达,回到低水平后又呈上升走势,说明氮同化效率得到提高;(3)在叶绿素合成途径中,处理组的关键酶基因CrHEMA1和CrCHLH的表达量在处理30 d后表达量显著增加,回到正常水平后呈逐渐上升趋势,与氮同化相关基因表达的趋势基本一致,对叶绿素的合成和积累有非常重要的作用。【结论】椪柑施氮后通过调控氮同化及叶绿素合成相关酶基因表达,显著提高椪柑叶片叶绿素含量和叶片净光合效率。
[Objective]The present study aimed at investigating the impact of nitrogen application on un- derlying mechanism of nitrogen assimilation and chlorophyll biosynthesis. [Method]Taking the 5-year-old ＇ Ota ponkan＇ as test material, through sostenuto nitrogen fertilization in the period of ponkan fruit devel- opment, dynamic changes of chlorophyll content and photosynthetic efficiency were determined termly, as well as several key enzyme genes in the process of nitrogen assimilation and chlorophyll biosynthesis.[Re- suh ] （1）leaf chlorophyll content and leaf net photosynthetic efficiency were remarkably increased; （2）Key enzyme gene CrGS2 in nitrogen assimilation displayed a continuous high level expression in the nitrogen application periods specially, both CrNADH-GOGAT and CrGOGAT had an excess expression signifi- cantly in 30 days after treatment, and then presented a rising trend again after back to low levels; （3）In chlorophyll biosynthesis pathway, both gene CrHEMA1 and CrCHLH had an intense expression in 30 days after treatment, basically identical with genes related with nitrogen assimilation, which is very cru- cial to the biosynthesis and accumulation of chlorophyll. [Conclusion]Nitrogen application can signifi- cantly increase chlorophyll content and leaf net photosynthetic efficiency mainly because the improvement of nitrogen assimilation efficiency.
出处
《果树学报》
CAS
CSCD
北大核心
2014年第1期7-12,共6页
Journal of Fruit Science
基金
农业部现代农业(柑橘)产业技术体系
湖南农业大学青年基金(12QN18)
关键词
桠柑
氮素
氮同化
叶绿素
关键酶基因
Ponkan
Nitrogen
Nitrogen assimilation
Chlorophyll
Key enzyme genes
