Tomato Pathogenesis-related Protein Genes are Expressed in Response to Trialeurodes vaporariorum and Bemisia tabaci Biotype B Feeding

The temporal and spatial expression of tomato wound- and defense-response genes to Bemisia tabaci biotype B (the silverleaf whitefly) and Trialeurodes vaporariorum (the greenhouse whitefly) feeding were characterized. Both species of whiteflies evoked similar changes in tomato gene expression. The levels of RNAs for the methyl jasmonic acid (MeJA)- or ethylene-regulated genes that encode the basic β-1,3-glucanase (GluB), basic chitinase (Chi9), and Pathogenesis-related protein-1 (PR-1) were monitored. GluB and Chi9 RNAs were abundant in infested leaves from the time nymphs initiated feeding (day 5). In addition, GluB RNAs accumulated in apical non-infested leaves. PR-1 RNAs also accumulated after whitefly feeding. In contrast, the ethylene- and salicylic acid (SA)-regulated Chi3 and PR-4 genes had RNAs that accumulated at low levels and GluAC RNAs that were undetectable in whitefly-infested tomato leaves. The changes in Phenylalanine ammonia lyase5 (PAL5) were variable; in some, but not all infestations, PAL5 RNAs increased in response to whitefly feeding. PAL5 RNA levels increased in response to MeJA, ethylene, and abscisic acid, and declined in response to SA. Transcripts from the wound-response genes, leucine aminopeptidase (LapA1) and proteinase inhibitor 2 (pin2), were not detected following whitefly feeding. Furthermore, whitefly infestation of transgenic LapA1:GUS tomato plants showed that whitefly feeding did not activate the LapA1 promoter, although crushing of the leaf lamina increased GUS activity up to 40 fold. These studies indicate that tomato plants perceive B. tabaci and T. vaporariorum in a manner similar to baterical pathogens and distinct from tissue-damaging insects

Matter against Materialism: Bruno Latour and the Turn to Objects

Bruno Latour, according to Andrew Barry, has been ‘extraordinarily influential across the social sciences in Britain’ (2011: 36). Latour’s ‘actor-network theory’ (Latour 2005) has, however, only been influential in literary and cultural studies comparatively recently (Latour 2004; Love 2010; Lupton 2011; Lupton 2015). This moment has coincided with and been reinforced by the turn to objects (Harman 2009; Harman 2012), and Latour’s own turn to metaphysical and philosophical questions (Latour 2013). I wish to track and dispute with this turn to Latour by analysing his work as operating by posing matter against materialism. Constant throughout Latour’s work is a suspicion of Marxism and of any ‘reductive’ materialism that would, according to Latour, privilege one dominant form of matter. In place of this Latour calls for an ‘irreduction’ (Latour 1988), which would treat ‘matter’, and ‘objects’, as matters of concern that resist stabilization. Literary studies has extended this point to dispute suspicious readings, which seek some ‘hidden’ explanation, in favour of description and the tracking of ‘objects’. This conforms to the general turn of the humanities towards the historical, conceived of as a site of material density, friction, and resistance. I argue that while this vision may be attractive it occludes the problem raised by Marxian ‘materialism’ concerning the forms of ‘real abstraction’ (Marx 1973; Sohn-Rethel 1978). These are forms of value, incarnated in the commodity-form, that cut across both matter and abstraction. For Marx (2010) the commodity is a ‘sensuous super-sensuous thing’ (innlich-übersinnlich), combining materiality and abstraction. This ‘occult character’ of the commodity is occluded in Latour’s turn to matter, or the recent turn to objects, even when unpacked as a series of relations or a mode of gathering. The desire for the concrete, in the form of matter, in fact composes what Alberto Toscano calls a ‘warm abstraction’ (2008: 58), which misses the force of abstraction. This problem is explored through the analysis and reading of Gordon Lish’s novel Peru (1986). The novel interweaves forms of abstraction and materiality, working between the repetitions of language and the experience of violence, while also engaging with the question of value in literary and economic terms. This intervention troubles the Latourian tendency to reduce abstraction onto a level field of multiple objects, while also suggesting that ‘materialism’ is not simply confined to ‘matter’ or ‘objects’. The result would be a reworked consideration of materialism against matter, which would contest Latour’s ‘matter against materialism’