氮素供应水平对小粒型花生氮素代谢及相关酶活性的影响

Effects of Nitrogen Level on Nitrogen Metabolism and Correlating Enzyme Activity of Peanut

花生籽仁蛋白质含量较高,研究不同品种花生各器官中氮代谢酶活性的差异及与籽仁蛋白质含量间的关系,可为花生优质高产提供依据。在大田高产条件下研究了氮素水平对小粒型花生各器官中可溶性蛋白质、游离氨基酸含量及氮代谢相关酶活性的影响,结果表明,适当提高氮素水平既能增加花生各器官中可溶性蛋白质和游离氨基酸的含量,又能提高硝酸还原酶、谷氨酰胺合成酶和谷氨酸脱氢酶等氮素同化酶的活性,使其达到同步增加;氮素水平过高虽能提高硝酸还原酶和籽仁蛋白质含量,但谷氨酰胺合成酶和谷氨酸脱氢酶的活性下降;N素施肥水平不改变花生植株各器官中硝酸还原酶(NR)、谷氨酰胺合成酶(GS)、谷氨酸脱氢酶(GDH)活性的变化趋势,但适量施N(B2、B3处理)使花生各营养器官中NR、GS活性提高;氮素水平对花生各叶片和籽仁中GDH活性的高低影响较大,但对茎和根中活性大小的影响则较小。

The effects of nitrogen level on soluble protein content, free amino acid content and correlating enzyme activity of nitrogen metabolism of peanut was studied in the field. The results showed that：with the increase of nitrogen, the soluble protein content and free amino acid content increased, and the activities of the nitrate reductase（NR）, glutamine synthetase （GS）and glutamate dehydrogenase（GDH） also increased at the same time;when the excessive nitrogen used, the NR activity and kernel protein content were increased, while the activities of GS and GDH were decreased;the change trends of NR, GS and GDH were not affected by the nitrogen level, but with suitable nitrogen the activities of NR and GS in different organs could be increased ; and the nitrogen level effected the GDH activity in leaf and kernel more obviously, with lower effects on its activity in stalk and root.