The plant terpenes DMNT and TMTT function as signaling compounds that attract Asian corn borer(Ostrinia furnacalis) to maize plants

During their co-evolution with herbivorous insects,plants have developed multiple defense strategies that resist pests,such as releasing a blend of herbivory-induced plant volatiles(HIPVs)that repel pests or recruit their natural enemies.However,the responses of insects to HIPVs in maize(Zea mays L.) are not well understood.Here,we demonstrate that the Asian corn borer(ACB,Ostrinia furnacalis),a major insect pest of maize,shows a preference for maize pre-infested with ACB larvae rather than being repelled by these plants.Through combined transcriptomic and metabolomics analysis of ACB-infested maize seedlings,we identified two substances that explain this behavior:(E)-4,8-dimethylnona-1,3,7-triene(DMNT) and(3E,7E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene(TMTT).DMNT and TMTT attracted ACB larvae,and knocking out the maize genes responsible for their biosynthesis via gene editing impaired this attraction.External supplementation with DMNT/TMTT hampered the larvae's ability to locate pre-infested maize.These findings uncover a novel role for DMNT and TMTT in driving the behavior of ACB.Genetic modification of maize to make it less detectable by ACB might be an effective strategy for developing maize germplasm resistant to ACB and for managing this pest effectively in the field.

萜烯同系物DMNT和TMTT的研究进展

近年来,学者对植物挥发性物质在功能和合成代谢方面的关注度越来越高。许多植物在被害虫侵袭后能够产生一些挥发性化学物质,而这些化学物质可以趋避害虫或吸引害虫天敌以达到间接防治害虫的目的。其中,(E)-4,8-二甲基-1,3,7-壬三烯((E)-3,8-dimethyl-1,4,7-nonatriene,DMNT)和(E,E)-4,8,12-三甲基-1,3,7,11-十三碳四烯((E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene,TMTT)在高等植物中广泛存在。这2种物质能够在植物受植食性昆虫侵害后诱导产生,并起到吸引相应的害虫天敌前来从而达到控制害虫的作用。同时,它们还具有吸引授粉昆虫、诱导邻近植物防御反应和趋避害虫等功能。本文主要从这2种物质的发现、生态学功能、生物合成、研究展望与应用前景等方面进行探讨,综述近年来植物中DMNT和TMTT的研究进展。

蓝莓、刺梨复合口服液的研制

蓝莓、刺梨具有丰富的营养价值和保健价值。为了充分利用蓝莓和刺梨资源,以蓝莓、刺梨的渣为主要原料,以调味剂为辅料,研究蓝莓、刺梨复合口服液的工艺研究。试验采用单因素试验和正交试验法找出最佳配比。试验结果表明,蓝莓、刺梨复合口服液的最佳配方为:蓝莓花色苷浓缩液15%,刺梨多糖4%,阿斯巴甜3%,大枣香精0.6%。采用最佳配比可以制得蓝莓、刺梨复合口服液,口服液的浓度适中,口感、色泽和稳定性良好。

Feeding of pea leafminer larvae simultaneously activates jasmonic and salicylic acid pathways in plants to release a terpenoid for indirect defense

The pea leafminer,Liriomyza huidobrensis,is an important pest species affecting ornamental crops worldwide.Plant damage consists of oviposition and feeding punctures created by female adult flies as well as larva-bored mines in leaf mesophyll tissues.How plants indirectly defend themselves from these two types of leafminer damage has not been sufficiently investigated.In this study,we compared the indirect defense responses of bean plants infested by either female adults or larvae.Puncturing of leaves by adults released green leaf volatiles and terpenoids,while larval feeding caused plants to additionally emit methyl salicylate and(E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene(TMTT).Puncturing of plants by female adults induced increases in jasmonic acid(JA)and JA-related gene expressions but reduced the expressions of salicylic acid(SA)-related genes.In contrast,JA and SA and their-related gene expression levels were increased significantly by larval feeding.The exogenous application of JA+SA significantly triggered TMTT emission,thereby significantly inducing the orientation behavior of parasitoids.Our study has confirmed that larval feeding can trigger TMTT emission through the activation of both JA and SA pathways to attract parasitoids;however,TMTT alone is less attractive than the complete blend of volatiles released by infested plants.

不同贮藏温度对刺梨果实品质影响

为延长刺梨鲜果的贮藏期及货架期,提高其商品价值。以＂贵农五号＂刺梨鲜果为试材,分别贮藏在温度为1℃±0.5℃,5℃±0.5℃和9℃±0.5℃,相对湿度90%~95%,气体成分O2：3%~5%,CO2：3%~5%的气调箱内,定期观察刺梨果实营养品质及生理变化。结果表明,贮藏在1℃±0.5℃温度条件下刺梨鲜果呼吸速率被抑制,营养成分保持在较高水平,果实硬度保持较好,PPO酶和POD酶活性显著（p〈0.05）低于其它处理组,MDA含量较低,成熟及衰老被抑制。贮藏后,刺梨果实的风味与品质较好,商品价值较高。其次为5℃±0.5℃贮藏组,最差为9℃±0.5℃贮藏组。低温显著延长刺梨鲜果的贮藏期及货架期。