Effects Of Direct Defensive Response In Neighbouring Jujube Exposed By Herbivore-Induced Plant Volatiles

Jujube armyworm (Ancylis Sativa. Liu), Lepidoptera, Tortricidae, is an important infested pest against jujube. Larvae can seriously feed leaves in bud stage and fruit mature stage, causing the second germination or fruit quality drop. Taking jujube and A. Sativa as materials, we researched direct defensive effects of neibouring jujube exposed by herbivore-induced plant volatiles (HIPVs) released from A. Sativa infested-jujube, explored transmission of wound-signal and direct defensive function in jujubes. The results as follow:After three days' feeding, PI, PPO and LOX activities in adjacent intra-shoot and inter-shoot aerating with herbivored-shoot were significantly higher than those adjacent shoots with no aeration. Three enzyme activities in no aerating shoot had no significant difference with uninfested control shoot. Moreover, in the condition of aeration, three enzyme activities in intra-shoot slightly higher than inter-shoot. These results indicate that HIPVs are an vital airborne wound-signal, primarily transmit by atmosphere among plants.After 24 hours' attack, PI, PPO and LOX amounts were greastest in A. Sativa feed plant among five days ventilation. In aerating neighboring jujube, three defensive enzymes significantly higher than the undamaged control jujube, and PI and LOX activities increased and then decreased, while PPO activity remained at a high level. Methyl jasmonate (MeJA) treatment had the same effect with A. Sativa feeding, however, though three enzyme activities increased rapidly to maximumafter 2 hour's GLVs exposedness, the duration of high activities were only 48 hours in contrast to 5 days exposed by HIPVs and MeJA induced volatiles (MeJA-VOCs). This illustrated that HIPVs, MeJA-VOCs and GLVs were important damage-signals, which could transmit to nearby plant by airborne, priming defense response in nearby plants.After 3 days' infestation, under natural conditions, three enzyme activities in infested-plant and adjacent plant all significantly higher than undamaged control jujube, moreover, PI activity in nearby plant was reflexional change, PPO activity was "W"-type change, LOX activity was presented "N" shape change. Judging from the defense response duration, the high PI activity (compared with the control) in adjacent plant sustained 5 days, PPO and LOX lasted over 5 days, but in herbivored-plant, the duration of three kind of enzymes continued much longer and stronger.In summary, this study proved signal function and transmission pathway in inter-jujube in field conditions, explored defense response mechanism in neighbouring jujube exposed by HIPVs.