摘要
为了探讨光照、NO3--N和NH4+-N对坛紫菜(Porphyra haitanensis)硝酸还原酶活性(NRA)的影响,在光照和黑暗条件下分别对坛紫菜叶状体进行氮(N)饥饿→氮(N)加富和N加富→N饥饿处理,并测定NRA的变化。结果表明:在N饥饿→N加富过程中,光照下NRA比黑暗中要高;NO3--N的加富能提高NRA,且在光照下比黑暗中NRA达到最大值的时间要短;而NH4+-N与NO3--N共同对N饥饿藻体加富时NRA没有明显变化,并与NH4+-N单独加富无显著差异。另外,对于N加富→N饥饿的处理,在光照下NO3--N加富和NH4+-N与NO3--N共同加富的NR都能在N饥饿处理后的一段时间内维持较高的活性。这些结果说明:光照和硝酸盐对NRA起正调节作用,而铵盐对NRA起负调节作用,但NRA与体外硝酸盐浓度并不成直接的正相关关系。
To investigate the effects of light, nitrate （NO3^--N） and ammonium （NH4^＋ -N） on the activity of nitrate reductase （NRA） in the red alga Porphyra haitanensis, thalli were incubated in seawater with different N supply （N-enrichment and N-starvation） in the light or in darkness. The results showed that NRA was higher in the light than in darkness; NRA increased when thalli were incubated in NO3^ --N, and it enhanced faster in the light than in darkness. There was no significant difference of NRA between thalli incubated in seawater enriched by NO3 ^--N and NH4 ^＋-N simultaneously and those enriched by NH4^＋ -N solely. Additionally, NR in light could maintain relative high activity for several hours when thalli were transferred from N-enrichment to N-starvation. It was concluded that light and / or NO3^ - -N increased NRA of Porphyra haitanensis, but NH4^＋ -N restrained it. However, NRA was not in direct proportion to the concentration of NO3^--N in culture.
出处
《水产学报》
CAS
CSCD
北大核心
2007年第1期90-96,共7页
Journal of Fisheries of China
基金
国家自然科学基金项目(30670396和30470343)
广东省自然科学基金项目(04010990)
广东省科技计划项目(2006B20601005)
关键词
坛紫菜
硝酸还原酶活性
氮饥饿
氮加富
光照
营养盐
Porphyra haitanensis
activity of nitrate reductase
N-starvation
N-enrichment
light
nutrient
