In:
eLife, eLife Sciences Publications, Ltd, Vol. 2 ( 2013-05-14)
Abstract:
Plants have developed a variety of strategies to defend themselves against herbivorous animals, particularly insects. In addition to mechanical defences such as thorns and spines, plants also produce compounds known as secondary metabolites that keep insects and other herbivores at bay by acting as repellents or toxins. Some of these metabolites are produced on a continuous basis by plants, whereas others—notably compounds called green-leaf volatiles—are only produced once the plant has been attacked. Green-leaf volatiles—which are also responsible for the smell of freshly cut grass—have been observed to provide plants with both direct protection, by inhibiting or repelling herbivores, and indirect protection, by attracting predators of the herbivores themselves. The hawkmoth Manduca sexta lays its eggs on various plants, including tobacco plants and sacred Datura plants. Once the eggs have hatched into caterpillars, they start eating the leaves of their host plant, and if present in large numbers, these caterpillars can quickly defoliate and destroy it. In an effort to defend itself, the host plant releases green-leaf volatiles to attract various species of Geocoris, and these bugs eat the eggs. One of the green-leaf volatiles released by tobacco plants is known as (Z)-3-hexenal, but enzymes released by M. sexta caterpillars change some of these molecules into (E)-2-hexenal, which has the same chemical formula but a different structure. The resulting changes in the ‘volatile profile’ alerts Geocoris bugs to the presence of M. sexta eggs and caterpillars on the plant. Now Allmann et al. show that adult female M. sexta moths can also detect similar changes in the volatile profile emitted by sacred Datura plants that have been damaged by M. sexta caterpillars. This alerts the moths to the fact that Geocoris bugs are likely to be attacking eggs and caterpillars on the plant, or on their way to the plant, so they lay their eggs on other plants. This reduces competition for resources and also reduces the risk of newly laid eggs being eaten by predators. Allmann et al. also identified the neural mechanism that allows moths to detect changes in the volatile profile of plants—the E- and Z- odours lead to different activation patterns in the moth brain.
Type of Medium:
Online Resource
ISSN:
2050-084X
DOI:
10.7554/eLife.00421.001
DOI:
10.7554/eLife.00421.002
DOI:
10.7554/eLife.00421.003
DOI:
10.7554/eLife.00421.004
DOI:
10.7554/eLife.00421.005
DOI:
10.7554/eLife.00421.006
DOI:
10.7554/eLife.00421.007
DOI:
10.7554/eLife.00421.008
DOI:
10.7554/eLife.00421.009
DOI:
10.7554/eLife.00421.010
DOI:
10.7554/eLife.00421.011
DOI:
10.7554/eLife.00421.012
DOI:
10.7554/eLife.00421.013
DOI:
10.7554/eLife.00421.014
DOI:
10.7554/eLife.00421.015
DOI:
10.7554/eLife.00421.016
DOI:
10.7554/eLife.00421.017
Language:
English
Publisher:
eLife Sciences Publications, Ltd
Publication Date:
2013
detail.hit.zdb_id:
2687154-3
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