The Arabidopsis thaliana/Myzus persicae model system demonstrates that a single gene can influence the interaction between a plant and a sap‐feeding insect

Abstract

We have developed an Arabidopsis thaliana / Myzus persicae model system to allow the dissection of plant/insect interactions at a molecular genetic level. This allows the examination of the role of single plant genes in the interaction between the plant and an aphid. Our initial studies have exploited an Arabidopsis genotype in which the function of the amino acid transporter ANT1 has been abolished. This mutation results in a change in the proportions of several amino acids within the phloem sieve elements (SEs) resulting in an increase in the proportion of essential amino acids. This has been measured using aphid stylectomy to collect SE samples, followed by a novel micellar electrokinetic chromatography method for amino acid analysis. The SE content represents the aphid's diet, and use of electrical penetration graph technology and honeydew clocks have demonstrated that this altered diet results in a change in the feeding rate of the aphid. Balance sheets can be produced to show the amount (nmoles/24 h) of each of 18 amino acids taken up and excreted by aphids feeding on wild type and ant1 mutant plants. The data show that aphids feeding on the ant1 mutant take up larger amounts of amino acids. However, we could not detect any effect on the reproductive rate of the aphids. The results show that, under experimental conditions, this model system can be used to identify plant genes that control the behaviour and fecundity of an insect pest.

A Diurnal Component to the Variation in Sieve Tube Amino Acid Content in Wheat

“…In previous work (Hunt et al, 2006), exuding ST sap was collected in paraffin oil to prevent evaporation of the sample. However, it has become apparent that the oil can potentially interfere with the subsequent analysis of amino acid contents by CE-LIF (data not shown).…”

“…The loss of function of ANT1, a member of the aromatic-neutral transporter family, was recently associated with a change in ST amino acid composition in Arabidopsis (Hunt et al, 2006). Furthermore, members of the AAP transporter subfamily have shown a specific pattern of expression linked with the vascular tissue (Fischer et al, 1995;Hirner et al, 1998;Okumoto et al, 2002Okumoto et al, , 2004 and also represent good candidates for the regulation of amino acid concentration and composition in the phloem.…”

“…We recently reported (Hunt et al, 2006) refinements of analytical techniques to measure amino acids (Zhu et al, 2005) in sap from individual exuding stylets using capillary electrophoresis coupled to laser-induced fluorescence detection (CE-LIF). CE-LIF is a powerful tool in bioanalysis, especially where sample volume is limited and high sensitivity is required (Tseng et al, 2007).…”

Co-localisation of host plant resistance QTLs affecting the performance and feeding behaviour of the aphid Myzus persicae in the peach tree

“…Therefore, the exact genetic relationship between plant resistance phenotypes and aphid behavioural abilities to detect and exploit nutrient sources often remained unknown. After the pioneering work of van Helden and Tjallingii (1993), only a few studies have been conducted, either on mutant plants (Hunt et al, 2006) or on near isogenic lines differing only in an aphid resistance gene (Kaloshian et al, 2000;Klingler et al, 2005). For tree species, the delay required to obtain such lines is a key problem.…”

Aphid–parasitoid community structure on genetically modified wheat

“…For instance, changes in phloem sap composition can affect organisms that feed upon these plants including sap-feeding aphids [3]. In an aphid -parasitoid -hyperparasitoid food web, the effects of host plant traits can cascade up as far as the fourth trophic level [2], even when there are no effects on the herbivores [4].…”