聚糠萘水剂对低温胁迫玉米幼苗氮代谢酶活的调控效应

以郑单958和丰单3号的3展叶期幼苗为材料,在人工气候室进行盆栽试验,研究4℃低温胁迫至幼苗死亡过程中叶片氮素代谢关键酶活的变化规律及聚糠萘水剂(PKN)的调控效应。结果表明,低温胁迫打破了氮素代谢平衡,致使氮素同化相关酶硝酸还原酶活性(NRA)、谷氨酰胺合成酶活性(GSA)和谷氨酸-草酰乙酸转移酶活性(GOTA)于胁迫初期升高,之后迅速下降,且GSA和GOTA降低比NRA提前2 d。随低温胁迫时间的延长,玉米幼苗受害加重,蛋白酶、肽酶活性增加,叶片可溶性蛋白与游离氨基酸含量升高。PKN处理提高了NRA、GSA、GOTA,降低了蛋白酶、肽酶活性,维持氮素代谢稳定,促进单株干物重增加,提高了玉米幼苗抗冷性。

Effects of PASP-KT-NAA on Nitrogen Metabolism Enzyme Activities of Maize Seedlings under Low Temperature Stress

A pot experiment of maize seedlings(material:Zhengdan958 and Fengdan3) was conducted in artificial climate chamber to investigate the effects of low temperature stress and the chemical regulator PKN with various nitrogen metabolism key enzymes activities. The results showed that the low temperature stress broken nitrogen metabolism balance and made NRA, GSA, GOTA significantly increasing in the beginning 2-3 days of the low temperature pressure, and then descended quickly. GSA and GOTA were faster than NRA 2 days. Low temperature stress increased protease and peptidase activity, promote protein decomposed. And soluble protein and free amino acid content increased. PKN pretreatment improved NRA, GSA, GOTA, maintained the stability of nitrogen metabolism and reduce the protease, peptidase activity, promoted the dry weight increased, improved the maize seedling cold resistance.