Local Adaptation of Aboveground Herbivores towards Plant Phenotypes Induced by Soil Biota

Background: Soil biota may trigger strong physiological responses in plants and consequently induce distinct phenotypes. Plant phenotype, in turn, has a strong impact on herbivore performance. Here, we tested the hypothesis that aboveground herbivores are able to adapt to plant phenotypes induced by soil biota. Methodology and Principal Findings: We bred spider mites for 15 generations on snap beans with three different belowground biotic interactions: (i) no biota (to serve as control), (ii) arbuscular mycorrhizal fungi and (ii) root-feeding nematodes. Subsequently, we conducted a reciprocal selection experiment using these spider mites, which had been kept on the differently treated plants. Belowground treatments induced changes in plant biomass, nutrient composition and water content. No direct chemical defence through cyanogenesis was detected in any of the plant groups. Growth rates of spider mites were higher on the ecotypes on which they were bred for 15 generations, although the statistical significance disappeared for mites from the nematode treatment when corrected for all multiple comparisons. Conclusion/Significance: These results demonstrate that belowground biota may indeed impose selection on the aboveground insect herbivores mediated by the host plant. The observed adaptation was driven by variable quantitativ

Characteristiques generales des bacteries lactiques

Beaucop de ces caracteres sont typiques et servent a definir le cour du groupe lactique que les reserches taxonomiques et phylogeniques sont en train de modifier de facon significative, coit au niveau des genres et des especes, soit au niveau de la ligne de demarcation avec d'autres groupes de bacteries. Les connaisances actuelles permettent neanmoins d'affirmer que le groupe des bacteries lactiques sensu stricto est forme de bacteries en forme de coque: Streptococcus, Lactococcus, Vagococcus, Enterococcus, Pediococcus, Aerococcus, Tetragenococcus, Leuconostoc et Atopobium, et de bacteries en forme de bacille: Lactobacillus et Carnobacterium. Mais l'appellation bacteries lactiques est souvent etendue a d'autres bacteries qui leur sont apparentees: Bifidobacterium, Micrococcus, Brevibacterium et Propionibacterium. La classication de ces bacteries en genres, especes, sous-especes et biovars s'etablit a l'aide de caracteres genotypiques et phenotypiques qui vont faire l'objet des developpements qui suiven

Belowground–aboveground interactions between pathogens and herbivores

Plants are attacked by pathogens and herbivores with a wide range of lifestyles, both belowground and aboveground. These pathogens and herbivores often co-occur on the same host plant, even though one of them may be in the roots and the other in the shoots. It has long been known that pathogens and herbivores can affect each other when sharing the same part of the plant, but more recently it has been shown that these interactions can span the belowground–aboveground divide. Root pathogens, for instance, can affect foliar herbivores, and, vice versa, foliar herbivores can affect root pathogens. Likewise, root herbivores can affect foliar pathogens and, vice versa, foliar pathogens can affect root herbivores. Such cross-compartment interactions are indirect (i.e., plant-mediated) and may involve induction and priming of common plant defenses, or altered plant quality. This chapter will review the literature and present a framework for this novel type of aboveground–belowground interactions between pathogens and herbivores