Transcriptome response analysis of Arabidopsis thaliana to leafminer (Liriomyza huidobrensis)

We first investigated local and systemic responses of A. thaliana to leafminer feeding using an Affymetrix ATH1 genome array. Genes related to metabolic processes and stimulus responses were highly regulated. Most systemically-induced genes formed a subset of the local response genes. We then downloaded gene expression data from online databases and used hierarchical clustering to explore relationships among gene expression patterns in A. thaliana damaged by different attackers.Our results demonstrate that plant response patterns are strongly coupled to damage patterns of attackers.Plants have evolved a complicated resistance system to defend against damages from various types of attackers. Based on many studies devoted to plant defense signal transduction, three main plant defense hormones have been identified. They are salicylic acid (SA), jasmonic acid (JA), and ethylene (ET), which are the key signal molecules involved in defense against pathogens, insects, and fungi, respectively [1-3]. It has recently been shown, however, that these signals are correlated in a very complex fashion; sometimes they conflict, while at other times they cooperate [4,5], indicating that plants express various defense patterns when damaged by different attackers. The factors determining these plant response patterns are still not clear, however.Plant responses to chewing insects and phloem-feeding insects are significantly different [6,7]. The two types of insects not only produce different elicitors, but also have different feeding guides. For example, wounding leads to leakage of plant cellular liquids, stimulating the mobilization of many defense pathways [8]; insect feeding causes similar damage to plants, but the elicitors in insect saliva can induce special plant defense proteins [9] or conversely suppress plant defense signals [10]. Phloem-feeding insects cause little wounding but have long damage durations, and plant defenses to these insects are thus slight [11,12]. In compa