烤烟感染赤星病后4种酶动态的研究

Dynamics of some Related Enzymes of Tobacco Infected with Brown Spot

本文研究１１个烤烟品种接种赤星病病菌后，过氧化物酶（ＰＯＤ）同工酶、多酚氧化酶（ＰＰＯ）、硝酸还原酶（ＮＲ）和抗坏血酸氧化酶（ＡＡＯ）活性的变化规律，结果表明，相对抗赤星病强的品种，ＰＰＯ在接种３６ｈ内活性升高，以后下降；ＰＯＤ同工酶活性变幅大，变化快，接种初期活性稍下降，然后增强，其中以阴极端２，４同工酶带增加较快，接种１８０ｈ后就由弱酶带变为强带；ＮＲ活性变化不大；ＡＡＯ活性提高．相反，抗赤星病弱的品种，ｐｐｏ活性低于对照；ＰＯＤ同工酶变化不大，呈下降趋势；ＮＲ活性变幅大；ＡＡＯ在接种初期活性下降，８４ｈ后回升．通过对不同品种的烤烟烟株接种赤星病菌后的４种酶活性的测定，探察到了一些抗病机理，为进一步筛选烟草抗赤星病的生化指标作了研究。

tobacco varieties were inoculated with pathogen of brown spot [Alternariaalternata(Fries) Keissler] ,their comparative disease resistance and the changing ac-tivities of some enzvmes namelv POD,PPO, NR, and AAO were investigated. Theorder of 11 tobacco varieties disease resistance in vitro leaf inoculation are as follow:311-8, 311-7, 311-3,④-2,V2,⑥-3, G28, P3, Gold Dolla, C2, K326. PODzymogram was isolated using vertical level polycrylamidegel electrophoresis and made itinto dry film and being scanned with a scanning instrument(CS-930) made inJapan. The POD activity of varieties like 311-8 which has higher resistance to brownspot changed very fast and the change scope were wider. At the initial stage of inocula-tion, the POD activitv downed a little and then increased, the more increased one wentinto 2, 4 isozymogram band on the anode. After inoculated 180 hours it was becomingfrom weak to strong band. The POD activity of varieties like C2 which has low resistantto brown sport changed little and had the tendency of declining. PPO and AAO activL-ties were measured bv iodometrv, for varieties with higher resistance to brown spot,their AAO activitv increased within 36 hours of inoculation and the PPO level was higherand then decreased. For varieties with low resistance their AAO activitv declined within36 hours of inoculation and then decreased.While PPO activity in all stages after inocu-lation was lower than that of CK, NR activity was measued by spectrophotometry,va-rieties such as 311-7with their NR activity changed little after inoculation;For varietieswith low resistance such as K326,the NR activity changed very much.By measuringthese enzvmes activitv,obtained some insight of disease resistant function, it served asbase for further studv of the biochemical indexes of tobacco brown spot resistance scan-ning.