To Feed or Not to Feed: Plant Factors Located in the Epidermis, Mesophyll, and Sieve Elements Influence Pea Aphid’s Ability to Feed on Legume Species

Abstract

The pea aphid (Acyrthosiphon pisum Harris), a legume specialist, encompasses at least 11 genetically distinct sympatric host races. Each host race shows a preference for a certain legume species. Six pea aphid clones from three host races were used to localize plant factors influencing aphid probing and feeding behavior on four legume species. Aphid performance was tested by measuring survival and growth. The location of plant factors influencing aphid probing and feeding was determined using the electrical penetration graph (EPG) technique. Every aphid clone performed best on the plant species from which it was originally collected, as well as on Vicia faba. On other plant species, clones showed intermediate or poor performance. The most important plant factors influencing aphid probing and feeding behavior were localized in the epidermis and sieve elements. Repetitive puncturing of sieve elements might be relevant for establishing phloem feeding, since feeding periods appear nearly exclusively after these repetitive sieve element punctures. A combination of plant factors influences the behavior of pea aphid host races on different legume species and likely contributes to the maintenance of these races.

Modulation of Legume Defense Signaling Pathways by Native and Non-native Pea Aphid Clones

“…When aphids initially penetrate plant tissue they regularly pierce and salivate into cells before arriving at the phloem and attempting to feed. Since aphids spend more time in this penetration phase on native than on non-native host plants (Schwarzkopf et al, 2013), they likely also pierce more cells and cause more tissue damage on native hosts. More damage should result in a stronger JA response to native aphid clones than to non-native clones, but this was not the case.…”

“…A genome-wide study of pea aphid host races was conducted and a few loci encoding salivary proteins were identified in regions under putative divergent selection (Jaquiery et al, 2012). Investigation of feeding behavior revealed that regardless of whether they are on their native host plant or another legume species, pea aphids start to penetrate the plant and to pierce and salivate into plant cells (Schwarzkopf et al, 2013). In order to find out what is salivated into the plant, transcriptomic analysis of salivary glands was conducted and around 600 pea aphid salivary genes were described (Carolan et al, 2011).…”

Dealing with food shortage: larval dispersal behaviour and survival on non‐prey food of the hoverfly Episyrphus balteatus

“…To test whether different plant-aphid combinations have altered attractiveness for hoverfly larvae, we used different combinations of pea aphid races and legume species. The pea aphid (Acyrthosiphon pisum HARRIS) is actually a species complex consisting of at least 15 genetically distinct host races which are native to particular legume species, but can all develop very well on the universal host plant Vicia faba (Ferrari et al, 2006;Ferrari et al, 2008;Peccoud et al, 2009a;Schwarzkopf et al, 2013;Peccoud et al, 2015). It is assumed that natural enemies contribute to the maintenance of the different host races by preferring to prey on aphids living on the general host plant V. faba, and therefore minimising the occurrence of mixed colonies (Vosteen et al, 2016a).…”

Survey and Pathogenicity of Black Spot Disease of Rose in Pakistan

“…However, the cultivars which have sufficient inherent resistance generally evade the attack of different species of pathogens [37,38]. The logic for this kind of broad-spectrum resistance is that different factors of plant resistance help these cultivars to resist against pathogen [39,40].…”