摘要
为进一步揭示硝酸还原酶(nitrate reductase,NR)活性的调控机制及其与植株体内硝酸盐含量的关系。本试验在正常供氮(15 mmol L^(–1)NO_3~–)和缺氮(7.5 mmol L^(–1)NO_3~–)条件下,以氮高效(H1:742和H2:Xiangyou 15)和氮低效(L1:814和L2:H8)油菜基因型为研究材料,通过NR活性的专性抑制剂处理,研究NR活性和硝酸盐含量的基因型和氮水平差异。结果表明,NR专性抑制剂处理可以显著降低叶片NR活性,正常供氮和缺氮条件下分别降低53.0%和57.6%,但对叶片硝酸盐的含量没有显著影响。正常供氮条件下的NR活性和硝酸盐含量比缺氮条件下分别高46.9%和16.4%。氮高效油菜基因型的硝酸盐含量显著低于氮低效基因型。H2的NR活性(NRA_(act))显著高于氮低效基因型的本质原因是其主效基因(nia2)的相对表达量高于氮低效基因型。本研究充分表明NR活性和硝酸盐含量存在明显的基因型和氮水平差异,一定程度的NR活性变化对植株体内硝酸盐的含量并没有显著的影响。
This study aims at inspecting the regulation mechanisms of NR activity and its relation to nitrate content in oilseed rape. A sand culture experiment with N treatment at normal （15 mmol L-1 NO3-） and deficiency （7.5 mmol L-t NO33 levels and NR activity obligate inhibitor treatment using oilseed rape genotypes with high nitrogen use efficiency （NUE） （HI： 742 and H2： Xiangyou 15） and low NUE （LI： 814 and L2： H8） was conducted to study differences of NR activity and nitrate contents between genotypes and N application levels. The results indicated that, compared with control treatment, inhibitor treatment under N nor- mal and deficiency levels decreased NR activity by 54.1% and 55.9% respectively, but could not influence the nitrate content of leaves. NR activity and nitrate content of N normal level treatment were 46.9% and 16.4% higher than those of N deficiency level. Nitrate content of high NUE genotypes was significantly lower than that of low NUE genotypes. NR activity （NRAact） of H2 was significantly higher than that of low NUE genotype, resulting from that H2 possesses higher relative expression level of major NR gene （nia2）. In conclusion, there are significant differences in NR activity and nitrate content between genotypes and N applica- tion levels. However, nitrate content can not be significantly influenced by somewhat changes of NR activity.
出处
《作物学报》
CAS
CSCD
北大核心
2013年第9期1668-1673,共6页
Acta Agronomica Sinica
基金
国家自然科学基金项目(31101596
31071851)
湖南农业大学人才引进基金项目(11YJ21)
湖南农业大学资源环境学院后备领军人才基金项目
省级教改一般项目(SCX1221)
植物分子遗传国家重点实验室开放课题基金
国家"十二五"科技支撑计划项目(2012BAD15B04)资助
关键词
硝酸还原酶(NR)
硝酸盐含量
油菜
基因型
氮水平
Nitrate reductase （NR）
Nitrate content
Oilseed rape （Brassica napus L.）
Genotypes
Nitrogen （N） application levels
