藜科植物S.L多糖抗病毒作用机理初步研究

对从藜科植物中提取的、具有诱导抗病毒作用的S.L多糖的作用机理做了初步的研究。首先将S.L多糖抽提液喷施烟草,探究S.L多糖诱导烟草对烟草花叶病毒(TMV)产生抗性的最佳时间。结果表明,用S.L多糖诱导植株产生的抗性在5 d左右达到最大,5 d之后抗病性随着时间的推移而减弱。在接种病毒前用S.L多糖对烟草幼苗进行喷施,然后于接种当天及接种后不同时间对各处理的同位等量叶片测定在总蛋白含量、过氧化物酶活性及同工酶图谱上的差异。研究发现,各处理的总蛋白含量均有所增加,且高于对照,并都于接种后的第9 d达到最大值。各处理的过氧化物酶活性在接种病毒初期均高于对照,但5 d后对照的酶活性超过处理,高峰较处理提前到来,且峰值略大于处理。在同工酶谱上,病毒接种后5 d,处理的酶带比对照浓且多了1条。5 d之后,二者的酶谱变得基本相同。到接种后10 d测定,结果相反,对照比处理的酶带浓。

Preliminary Study on the Mechanism of Plant Resistance Inducement Against TMV by the Chenopodiaceae Polysaccharide Extract

S.L belongs to Chenopodiaceae,its polysaccharide extract can induce the resistance of plant against tobacco mosaic virus(TMV).A preliminary research was made on the mechanism about the S.L-induced resistance to viral infection in tobacco.It was investigated that how long the S.L-induced resistance will take in the plant which were treated by the polysaccharide extract at different time before inoculation.It is showed that the disease incidence index of the plant treated by S.L extract was much lower than the control,and the disease incidence was reduced by 4.31% to 45.75%.The best inducing effect was in 5 days later after the tobacco was treated by the polysaccharide.So,it can be inferred that S.L-induced resistance reaches to the top in about 5 days.5 days later after the treatment,the resistance induced by S.L polysaccharide becomes lower as time goes by.In further experiment,there were four groups of tobacco.Three of the groups are treated by the extract respectively 5,3,1 days before inoculation,while the control was sprayed just with water.Then,the total protein content,peroxidase activity and isoenzyme genealogy was compared between the different treatments.The results showed there was no much difference among all groups of tobacco about the total protein content.But the peroxidase of the three treated groups and the control went to a peak in different time after virus inoculation.The peroxidase of all the treated groups peaked 9 days later after inoculation,and the peak a little later and lower than the control.Another,the isoenzyme genealogies analysis of different treatments indicated that S.L polysaccharide can induce more isoenzyme expression much more earlier than the control.