Microarray analysis of salicylic acid‐ and jasmonic acid‐signalling in responses of Nicotiana attenuata to attack by insects from multiple feeding guilds

Abstract

Resistance to herbivore attack is elicited by damage-and herbivore-specific signals. To understand the role of salicylic acid (SA) and jasmonic acid (JA) signalling in the herbivore-induced transcriptional responses of the native tobacco Nicotiana attenuata , a comparison was made of the responses in undamaged systemic leaves after attack by five herbivore species ( Manduca sexta , Spodoptera littoralis , Trichoplusia ni , Tupiocoris notatus and Myzus nicotianae ) from three feeding guilds and to elicitation by SA, BTH and methyl-JA with a 789-gene oligo-microarray and measured endogenous SA and JA levels. Systemic responses to M. sexta attack were similar to the responses in locally attacked tissues; however, the up-regulation of genes (such as proteinase inhibitor, PI) was more attenuated and resembled the responses to attack from the other Lepidopteran, S. littoralis, and to methyl-JA elicitation. Responses to attack from the puncture-feeding T. notatus repressed some JA-elicited genes (PI) elicited by the leafchewing Lepidopterans and most closely resembled SA elicitation. Attack from the phloem-feeding M. nicotianae aphids elicited few responses. Treatment with the SAmimic BTH induced both SA-and JA-elicited genes and most closely resembled the aphid response. SA concentrations were uniformly increased by herbivore attack and correlated with the down-regulation of photosynthetic genes in all treatments.

Remote sensing of future competitors: Impacts on plant defenses

“…Harvested leaves were immediately frozen in liquid nitrogen. Previously described protocols were used for RNA extraction (17), gene selection, array design, hybridization, scanning, image analysis, background correction, and slide-specific normalization (16). The ratios of normalized fluorescence values for Cy3 and Cy5 of each individual spot (expression ratio) and the mean of the replicate spots for each cDNA were calculated and are published in Table 1.…”

Predicted Effector Molecules in the Salivary Secretome of the Pea Aphid (Acyrthosiphon pisum): A Dual Transcriptomic/Proteomic Approach

“…There is a growing body of evidence that plant defense against sap-feeding insects such as aphids follows the plant-pathogen model as presented by Jones and Dangl. 5 For instance, aphid-induced gene expression in the plant is more similar to a typical pathogen response than to that caused by a chewing insect, 6 reviewed in ref 7. In addition the only cloned aphid resistance genes, the Mi gene in tomato 8 and the Vat gene in melon, 9 are members of the CC-NBS-LRR family of resistance proteins (R proteins) that confer resistance to both prokaryotic and eukaryotic pathogens.…”

Loss of Function of FATTY ACID DESATURASE7 in Tomato Enhances Basal Aphid Resistance in a Salicylate-Dependent Manner

“…Aphids and whiteflies extract phloem sap through slender mouth parts that cause far less mechanical injury than the mandibles of chewing insects (Walling, 2008), and to date, they have not been reported to induce detectable levels of JA (Heidel and Baldwin, 2004;De Vos et al, 2005). The decoy hypothesis posits that these phloem-feeding insects limit the induction of JA-dependent defenses by inducing SA, which can interact antagonistically with JA signaling (Zhu-Salzman et al, 2004;de Vos et al, 2007).…”