Technical Abstract: Upon herbivore and pathogen attacks, plants switch from processes supporting growth and reproduction to defense by inducing a set of defense genes and down-regulating most of the nuclear encoded photosynthetic genes. To determine if this transcriptional response is universal we used transcriptome data generated from microarray experiments after twenty-two different forms of biotic damage, including viral, fungal, bacterial and herbivore attack on eight different plant species. Mechanical wounding, phytohormone and regurgitant treatments also were included in the analysis. The hierarchical cluster analysis of photosynthesis light reaction and pigment synthesis genes revealed that transcript levels decreased uniformly regardless of the type of attack. Similarly, transcripts for genes coding for proteins unique to the Calvin cycle were uniformly down-regulated following biotic damage. The corresponding up-regulation of genes coding for the synthesis of Jasmonic acid and those involved in the responses to salicylic acid and ethylene, core defense hormones, suggest that the down-regulation of photosynthesis was related to mounting a defense. The determination of subcellular localization of co-expressed gene clusters showed that the transcript levels of 84% of the genes that carry a chloroplast targeting peptide sequence decreased. The majority of these down-regulated, chloroplast-targeted genes shared common regulatory elements, such as G-box (CACGTG), T-box (ACTTTG) and SORLIP (GCCAC) motifs. Strong convergence in the response of transcriptions suggests that the universal down-regulation of photosynthesis is an adaptive response to biotic attack, but the benefits of this response are not yet known.