Disruption of plant carotenoid biosynthesis through virus‐induced gene silencing affects oviposition behaviour of the butterfly Pieris rapae

Abstract

Summary• Optical plant characteristics are important cues to plant-feeding insects. In this article, we demonstrate for the first time that silencing the phytoene desaturase (PDS) gene, encoding a key enzyme in plant carotenoid biosynthesis, affects insect oviposition site selection behaviour.• Virus-induced gene silencing employing tobacco rattle virus was used to knock down endogenous PDS expression in three plant species (Arabidopsis thaliana, Brassica nigra and Nicotiana benthamiana) by its heterologous gene sequence from Brassica oleracea.• We investigated the consequences of the silencing of PDS on oviposition behaviour by Pieris rapae butterflies on Arabidopsis and Brassica plants; first landing of the butterflies on Arabidopsis plants (to eliminate an effect of contact cues); first landing on Arabidopsis plants enclosed in containers (to eliminate an effect of volatiles); and caterpillar growth on Arabidopsis plants. Our results show unambiguously that P. rapae has an innate ability to visually discriminate between green and variegated green-whitish plants. Caterpillar growth was significantly lower on PDS-silenced than on empty vector control plants. This study presents the first analysis of PDS function in the interaction with an herbivorous insect.• We conclude that virus-induced gene silencing is a powerful tool for investigating insect-plant interactions in model and nonmodel plants.

Photosynthetic Quantum Yield Dynamics: From Photosystems to Leaves

“…Considering that a significant fraction of the shorter wavelengths is absorbed by chlorophylls (Gitelson et al, 2002), that carotenoids still have an average energy transfer efficiency of ;65%, and that for the blue wavelengths a est is up to 50% higher than a ( Figure 8), a considerable proportion of the quantum yield losses at the shorter wavelengths must be attributable to nonphotosynthetic pigments. The absorptance spectrum of the albino cucumber leaves (Figure 3) was similar to that found for albino leaf zones of Arabidopsis thaliana in which a gene encoding a key enzyme in carotenoid synthesis was knocked out by virus-induced gene silencing (Zheng et al, 2010). These absorptance spectra qualitatively indicate that nonphotosynthetic pigments absorbed at wavelengths <520 nm, which is in agreement with the lower values of a than those of a est (Figure 8).…”

Transcription Factor-Mediated Control of Anthocyanin Biosynthesis in Vegetative Tissues

“…Silencing of PDS resulted in photobleaching (Supplemental Fig. S5A), causing white patches and white leaves, and is therefore easily detected visually (Velásquez et al, 2009;Zheng et al, 2010). After 11 d, white patches and white leaves were observed, mainly in the newly formed leaves.…”

Silencing Defense Pathways in Arabidopsis by Heterologous Gene Sequences from Brassica oleracea Enhances the Performance of a Specialist and a Generalist Herbivorous Insect

“…We employed a heterologous gene sequence, i.e., phytoene desaturase (BoPDS) from B. oleracea, to silence its ortholog in A. thaliana plants. We found that disruption of this specific gene of the carotenoid biosynthetic pathway through VIGS affected vision-mediated oviposition behavior of the butterfly Pieris rapae (Zheng et al, 2010). In the present study, we used B. oleracea gene sequences to silence two genes, lipoxygenase (AtLOX) and thioglucoside glucohydrolase: myrosinase (AtTGG) in A. thaliana plants because silencing BoLOX and BoMYR in cabbage plants themselves has not yet been successful.…”

“…Such VIGS vectors have been used to silence genes mainly in a number of solanaceous plant species, including tobacco, tomato, pepper, potato, and petunia (Shao et al, 2008). Optimized procedures aimed at improving the efficiency of agro-infiltration of A. thaliana have been reported in recent years (BurchSmith et al, 2006;Wang et al, 2006;Pflieger et al, 2008;Zheng et al, 2010). VIGS has obvious advantages over other known approaches for gene function analysis (Scofield and Nelson, 2009).…”

“…We developed a loss-of-function approach with TRVmediated VIGS for A. thaliana plants (Zheng et al, 2010). We employed a heterologous gene sequence, i.e., phytoene desaturase (BoPDS) from B. oleracea, to silence its ortholog in A. thaliana plants.…”