Effects of Valsa mali var. mali Infection on Defense Enzymes Activity and MDA Content in Apple Callus
In this study, susceptible cultivar (‘Fuji’) and resistant rootstock (Malus hupehensis) were used to in-vestigate the dynamic changes of defense enzymes activity and MDA content in the callus infected with V. mali isolate LXS080601. After inoculation, apple callus disease index, MDA content and activities of defense en-zymes including phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), superoxide dismutase (SOD) and peroxidase (POD) were determined. The results showed that, the disease severity and infection index of‘Fuji’ callus were signiifcantly higher than M. hupehensis infected with LXS080601. MDA content increased in the callus inoculated with LXS080601. Specially, MDA content increased from-0.32%to 36.39%in‘Fuji’ cal-lus, the changes of which were more noticeable than those in the resistant rootstock from-2.17%to 7.46%. In addition, four kinds of defense enzymes activities increased in callus after LXS080601 infection. PPO and POD activities peaked at one to two days post inoculation while PAL and SOD activities reached highest at three to four days post inoculation. Except for PPO, the activity changes of other three enzymes were signiifcantly high-er in M. hupehensis than in‘Fuji’. After reaching the peaks, the activities of PAL, SOD and POD in‘Fuji’ de-creased dramatically whereas the enzymes activities in M. hupehensis declined very slowly and maintained higher activities during the whole infection. The results suggested that M. hupehensis obtained resistance against V. mali infection in part by reducing the accumulation of reactive oxygen species and the production of MDA through enhanced antioxidant defense system.
NETL
NSTL
万方数据
维普
