渗透胁迫对小麦幼苗硝酸还原酶钝化蛋白的影响

EFFECT OF OSMOTIC STRESS ON NITRATE REDUCTASE-INACTIVATING PROTEIN OF WHEAT SEEDLINGS

渗透胁迫下郑引一号（干旱敏感品种）幼苗硝酸还原酶（ＮＲ）活性下降的速率比陕合六号（抗旱品种）的快。小麦幼苗中含有ＮＲ钝化蛋白部分Ⅰ和部分Ⅱ，其中部分Ⅱ对ＮＲ的钝化活性大于部分Ⅰ；随着渗透胁迫的加剧，陕合六号与郑引一号的ＮＲ钝化蛋白部分Ⅰ的钝化活性减小百分率相近，郑引一号的ＮＲ钝化蛋白部分Ⅱ的钝化活性上升百分速率则快于陕合六号的，因而，在渗透胁迫下，郑引一号的总ＮＲ钝化蛋白活性比陕合六号的高。

Under osmotic stress,nitrate reductase activity of wheat seedlings(Zhengyin No.1.drought-sensitive wheat cultivar)decreased more rapidly than that of Shanhe NO.6(drought-resistantwheat cultivar)did.These two cultivar seedings contained NR-inactivating protein partⅠandpartⅡ,and the inactivation ability of part Ⅱ was stronger than that of part I.Withosmotic strcSs,the activity of NR-inactivating protein partⅠdecreased in similar degaree inShanhe No.6 and Zhengyin No.1.while the activityf of NR-inactivating protein part Ⅱin Zhengyin No,1 increased more rapidly than that of Shanhe No.6.Thus,the totalcontent of NR-inactivating protein in Zhengyin No,1 was higher than that ofshanhe No.6.