Tayal Mandeep, Somavat Pavel, Rodriguez Isabella, Thomas Tina, Christoffersen Bradley, Kariyat Rupesh
Department of Biology, The University of Texas Rio Grande Valley, Edinburg, TX 78539, USA.
School of Earth, Environmental, and Marine Sciences, The University of Texas Rio Grande Valley, Edinburg, TX 78539, USA.
Insects. 2020 Feb 2;11(2):98. doi: 10.3390/insects11020098.
Plant secondary metabolites such as terpenes, phenolics, glycosides, and alkaloids play various functional roles including pigmentation, foliar and floral volatile synthesis, hormonal regulation, and direct and indirect defenses. Among these, phenolic compounds are commonly found in plants, but vary in the distribution of their specific compounds among plant families. Polyphenols, including anthocyanins and tannins, are widely distributed and have been well documented for their roles- primarily in plant pigmentation and also in plant defenses. However, commercialization of such compounds for use in insect pest management is severely hampered by expensive, inefficient, and time-consuming extraction protocols. Using a recently developed inexpensive and easy extraction method using the byproducts of pigmented (purple) corn processing, we examined whether the crude pericarp extract rich in polyphenols can affect the growth and development of tobacco hornworm ( L.) caterpillars. Our findings show that purple corn pericarp extract negatively affected egg hatching and larval mass gain and prolonged developmental time compared to regular yellow corn extract or an artificial control diet. We also found that these effects were more severe during the early stages of caterpillar development. These results conclusively demonstrate that purple corn pericarp, an inexpensive by-product of the corn milling industry, is a valuable product with excellent potential as an insect antifeedant.
植物次生代谢产物，如萜类、酚类、糖苷和生物碱，发挥着各种功能作用，包括色素沉着、叶和花挥发性物质合成、激素调节以及直接和间接防御。其中，酚类化合物在植物中普遍存在，但在不同植物科中其特定化合物的分布有所不同。多酚类物质，包括花青素和单宁，分布广泛，其作用已得到充分记录——主要在植物色素沉着以及植物防御方面。然而，用于害虫管理的此类化合物的商业化受到昂贵、低效和耗时的提取方法的严重阻碍。我们使用最近开发的一种利用有色（紫色）玉米加工副产品的廉价且简便的提取方法，研究了富含多酚的粗制果皮提取物是否会影响烟草天蛾幼虫的生长和发育。我们的研究结果表明，与普通黄色玉米提取物或人工对照饲料相比，紫色玉米果皮提取物对卵孵化和幼虫体重增加有负面影响，并延长了发育时间。我们还发现，这些影响在毛虫发育的早期阶段更为严重。这些结果确凿地证明，紫色玉米果皮作为玉米磨粉工业的一种廉价副产品，是一种具有作为昆虫拒食剂巨大潜力的有价值产品。
