低温及其信息素蛔甙对松材线虫睡眠的影响

[目的] 温度作为生态环境的重要组成因子,深刻影响松材线虫的生态分布,本研究旨在探讨松材线虫对温度的响应及其生态适应机制,为松材线虫防治提供依据。[方法] 分别测定了不同龄期松材线虫在25和4℃条件下处理48 h后静息率、糖醇含量和蛔甙的变化,以及蛔甙常温处理18 h后对线虫成虫静息率的影响。[结果] 与25℃对照处理相比,4℃条件下L₂、L₃、L₄和成虫的静息率大幅提升;4℃条件下海藻糖含量显著高于25℃对照处理,约为对照处理的2.32倍,而山梨糖醇、葡萄糖和甘油含量与对照处理均无明显差异;蛔甙测定结果显示,C5、C6和ΔC6含量均下调,C7和ΔC9停止分泌,而C9在4℃条件下开始分泌;生物测定表明,粗提物、C6、C7和C9能大幅增加线虫在25℃条件下的静息率。[结论] 几种蛔甙共同参与了松材线虫低温压力诱导睡眠的调控。     

Nematode ascaroside enhances resistance in a broad spectrum of plant–pathogen systems

Recognition of specific molecule signatures of microbes, including pathogens, induces innate immune responses in plants, as well as in animals. Analogously, a nematode pheromone, the ascaroside ascr#18, induces hallmark plant defences including activation of (a) mitogen‐activated protein kinases, (b) salicylic acid‐ and jasmonic acid‐mediated defence signalling pathways and (c) defence gene expression and provides protection to a broad spectrum of pathogens. Ascr#18 is a member of an evolutionarily conserved family of nematode signalling molecules and is the major ascaroside secreted by plant–parasitic nematodes. Here, we report the effects of ascr#18 on resistance in four of the major economically important crops: maize, rice, wheat and soybean to some of their associated pathogens. Treatment with low nanomolar to low micromolar concentrations of ascr#18 provided from partial to strong protection in seven of eight plant–pathogen systems tested with viruses, bacteria, fungi, oomycetes and nematodes. This research may have potential to improve agricultural sustainability by reducing use of potentially harmful agrochemicals and enhance food security worldwide.     

Pheromones and Nutritional Signals Regulate the Developmental Reliance on let-7 Family MicroRNAs in C. elegans

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线虫蛔甙(Ascarosides)信息素研究进展

大多数生物通过信息素系统来对环境进行感应和个体间交流,并指导其行为、发育和生理代谢。线虫是在地球上生存策略最多样的动物之一,但其信息素系统却鲜为人知。近年来发现一组称为蛔甙(ascarosides)的线虫种内化学信号物质,在秀丽隐杆线虫(Caenorhabditis elegans)的交配、聚集和滞育等行为及发育调控方面起着至关重要的作用。随后发现蛔甙在线虫界广泛存在。对蛔甙进行深入全面的了解有利于促进线虫化学生态学学科发展,并填补传统化学生态学中关于化学信息对生物发育调控的知识。因此,对近年来蛔甙的最新研究进展进行了系统总结,包括蛔甙结构与鉴定、组成和功能、生物合成与代谢调控、化学感受信号途径及信息调节模式,从而更好地理解化感信号对线虫乃至高等生物的行为、发育、新陈代谢及衰老的调控机制,为研究生命科学中信息素调控理论提供新的参考。     

Sex-specific,pdfr-1-dependent modulation of pheromone avoidance by food abundance enables flexibility in C. elegans foraging behavior

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