scholarly journals Distinct defense strategies allow different grassland species to cope with root herbivore attack

2019 ◽  
Author(s):  
Maxime R Hervé ◽  
Matthias Erb
Keyword(s):  
Plant Species ◽  
Tissue Loss ◽  
Insect Herbivores ◽  
List Type ◽  
Spotted Knapweed ◽  
Defense Strategies ◽  
Grassland Species ◽  
Melolontha Melolontha ◽  
Common Dandelion ◽  
Root Herbivore

AbstractRoot-feeding insect herbivores are of substantial evolutionary, ecological and economical importance. Plants can resist insect herbivores through a variety of tolerance and resistance strategies. To date, few studies have systematically assessed the prevalence and importance of these strategies for root-herbivore interactions across different plant species.Here, we characterize the defense strategies used by three different grassland species to cope with a generalist root herbivore, the larvae of the European cockchafer Melolontha melolontha.Our results reveal that the different plant species rely on distinct sets of defense strategies. The spotted knapweed (Centaurea stoebe) resists attack by dissuading the larvae through the release of repellent chemicals. White clover (Trifolium repens) does not repel the herbivore, but reduces feeding, most likely through structural defenses and low nutritional quality. Finally, the common dandelion (Taraxacum officinale) allows M. melolontha to feed abundantly but compensates for tissue loss through induced regrowth.Synthesis: Three co-occurring plant species have evolved different solutions to defend themselves against attack by a generalist root herbivore. The different root defense strategies may reflect distinct defense syndromes.

scholarly journals A beta-glucosidase of an insect herbivore determines both toxicity and deterrence of a dandelion defense metabolite

2021 ◽  
Author(s):  
Meret Huber ◽  
Thomas Roder ◽  
Sandra Irmisch ◽  
Alexander Riedel ◽  
Saskia Gablenz ◽  
...  
Keyword(s):  
Plant Defense ◽  
Feeding Preference ◽  
Melolontha Melolontha ◽  
Herbivore Interactions ◽  
The Common ◽  
Common Dandelion ◽  
Beta Glucosidase ◽  
Insect Gut ◽  
Root Herbivore ◽  
Plant Herbivore

Gut enzymes can metabolize plant defense metabolites and thereby affect the growth and fitness of insect herbivores. Whether these enzymes also influence herbivore behavior and feeding preference is largely unknown. We studied the metabolization of taraxinic acid β-D-glucopyranosyl ester (TA-G), a sesquiterpene lactone of the common dandelion (Taraxacum officinale) that deters its major root herbivore, the common cockchafer larva (Melolontha melolontha). We demonstrate that TA-G is rapidly deglycosylated and conjugated to glutathione in the insect gut. A broad-spectrum M. melolontha β-glucosidase, Mm_bGlc17, is sufficient and necessary for TA-G deglycosylation. Using plants and insect RNA interference, we show that Mm_bGlc17 reduces TA-G toxicity. Furthermore, Mm_bGlc17 is required for the preference of M. melolontha larvae for TA-G deficient plants. Thus, herbivore metabolism modulates both the toxicity and deterrence of a plant defense metabolite. Our work illustrates the multifacteted roles of insect digestive enzymes as mediators of plant-herbivore interactions.

scholarly journals A beta-glucosidase of an insect herbivore determines both toxicity and deterrence of a dandelion defense metabolite

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Meret Huber ◽  
Thomas Roder ◽  
Sandra Irmisch ◽  
Alexander Riedel ◽  
Saskia Gablenz ◽  
...  
Keyword(s):  
Plant Defense ◽  
Feeding Preference ◽  
Defense Compounds ◽  
Melolontha Melolontha ◽  
The Common ◽  
Common Dandelion ◽  
Beta Glucosidase ◽  
Insect Gut ◽  
Root Herbivore ◽  
Plant Herbivore

Gut enzymes can metabolize plant defense compounds and thereby affect the growth and fitness of insect herbivores. Whether these enzymes also influence feeding preference is largely unknown. We studied the metabolization of taraxinic acid β-D-glucopyranosyl ester (TA-G), a sesquiterpene lactone of the common dandelion (Taraxacum officinale) that deters its major root herbivore, the common cockchafer larva (Melolontha melolontha). We have demonstrated that TA-G is rapidly deglucosylated and conjugated to glutathione in the insect gut. A broad-spectrum M. melolontha β-glucosidase, Mm_bGlc17, is sufficient and necessary for TA-G deglucosylation. Using cross-species RNA interference, we have shown that Mm_bGlc17 reduces TA-G toxicity. Furthermore, Mm_bGlc17 is required for the preference of M. melolontha larvae for TA-G-deficient plants. Thus, herbivore metabolism modulates both the toxicity and deterrence of a plant defense compound. Our work illustrates the multifaceted roles of insect digestive enzymes as mediators of plant-herbivore interactions.

Range extensions of grassland species in southern interior British Columbia

1985 ◽  
Vol 63 (12) ◽  
pp. 2240-2242
Author(s):  
Brian M. Wikeem ◽  
Reg F. Newman
Keyword(s):  
British Columbia ◽  
Plant Species ◽  
Field Studies ◽  
Grassland Species

Field studies and herbarium searches during 1983 and 1984 have revealed range extensions of three grassland plant species in the southern interior of British Columbia. These species include Allium geyeri Wats. var. tenerum Jones, Gaura coccinea (Nutt.) Pursh, and Sidalcea oregana (Nutt.) Gray ssp. oregana var. procera C. L. Hitchc. All three taxa were previously unknown to the Kamloops area and Sidalcea oregana is new to the province and Canada.

scholarly journals Are declines in insects and insectivorous birds related?

The Condor ◽  
2021 ◽  
Author(s):  
Douglas W Tallamy ◽  
W Gregory Shriver
Keyword(s):  
Plant Species ◽  
Invasive Plant ◽  
Bird Species ◽  
Insect Herbivores ◽  
Native Plant ◽  
Insectivorous Birds ◽  
Population Declines ◽  
Native Plant Species ◽  
Host Plant Specialization ◽  
Scale Population

Abstract A flurry of recently published studies indicates that both insects and birds have experienced wide-scale population declines in the last several decades. Curiously, whether insect and bird declines are causally linked has received little empirical attention. Here, we hypothesize that insect declines are an important factor contributing to the decline of insectivorous birds. We further suggest that insect populations essential to insectivorous birds decline whenever non-native lumber, ornamental, or invasive plant species replace native plant communities. We support our hypothesis by reviewing studies that show (1) due to host plant specialization, insect herbivores typically do poorly on non-native plants; (2) birds are often food limited; (3) populations of insectivorous bird species fluctuate with the supply of essential insect prey; (4) not all arthropod prey support bird reproduction equally well; and (5) terrestrial birds for which insects are an essential source of food have declined by 2.9 billion individuals over the last 50 years, while terrestrial birds that do not depend on insects during their life history have gained by 26.2 million individuals, a 111-fold difference. Understanding the consequences of insect declines, particularly as they affect charismatic animals like birds, may motivate land managers, homeowners, and restoration ecologists to take actions that reverse these declines by favoring the native plant species that support insect herbivores most productively.

scholarly journals Effects of bioavailable phosphorus and soil biota on typical Nardus grassland species in competition with fast-growing plant species

2021 ◽  
Vol 120 ◽  
pp. 106880
Author(s):  
Stephanie Schelfhout ◽  
Safaa Wasof ◽  
Jan Mertens ◽  
Margot Vanhellemont ◽  
Andreas Demey ◽  
...  
Keyword(s):  
Plant Species ◽  
Soil Biota ◽  
Grassland Species ◽  
Bioavailable Phosphorus ◽  
Fast Growing

scholarly journals Host specificity of insect herbivores in tropical forests

2005 ◽  
Vol 272 (1568) ◽  
pp. 1083-1090 ◽  
Author(s):  
Vojtech Novotny ◽  
Yves Basset
Keyword(s):  
Host Specificity ◽  
Tropical Forests ◽  
Plant Species ◽  
Field Studies ◽  
Tropical Species ◽  
Distribution Data ◽  
Insect Herbivores ◽  
Leaf Miners ◽  
Experimental Conditions ◽  
Plant Phylogeny

Studies of host specificity in tropical insect herbivores are evolving from a focus on insect distribution data obtained by canopy fogging and other mass collecting methods, to a focus on obtaining data on insect rearing and experimentally verified feeding patterns. We review this transition and identify persisting methodological problems. Replicated quantitative surveys of plant–herbivore food webs, based on sampling efforts of an order of magnitude greater than is customary at present, may be cost-effectively achieved by small research teams supported by local assistants. Survey designs that separate historical and ecological determinants of host specificity by studying herbivores feeding on the same plant species exposed to different environmental or experimental conditions are rare. Further, we advocate the use of host‐specificity measures based on plant phylogeny. Existing data suggest that a minority of species in herbivore communities feed on a single plant species when alternative congeneric hosts are available. Thus, host plant range limits tend to coincide with those of plant genera, rather than species or suprageneric taxa. Host specificity among tropical herbivore guilds decreases in the sequence: granivores>leaf-miners>fructivores>leaf-chewers=sap-suckers>xylophages>root-feeders, thus paralleling patterns observed in temperate forests. Differences in host specificity between temperate and tropical forests are difficult to assess since data on tropical herbivores originate from recent field studies, whereas their temperate counterparts derive from regional host species lists, assembled over many years. No major increase in host specificity from temperate to tropical communities is evident. This conclusion, together with the recent downward revisions of extremely high estimates of tropical species richness, suggest that tropical ecosystems may not be as biodiverse as previously thought.

Plant Bio-Wars: Maize Protein Networks Reveal Tissue-Specific Defense Strategies in Response to a Root Herbivore

2018 ◽  
Vol 44 (7-8) ◽  
pp. 727-745 ◽  
Author(s):  
Lina Castano-Duque ◽  
Anjel Helms ◽  
Jared Gregory Ali ◽  
Dawn S. Luthe
Keyword(s):  
Protein Networks ◽  
Tissue Specific ◽  
Defense Strategies ◽  
Maize Protein ◽  
Root Herbivore
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