Comparative physiological and proteomic analysis of Arabidopsis thaliana revealed differential wound stress responses following the exposure to different LED light sources

Abstract

A comparative proteomic analysis was carried out to investigate the effects of various Light Emitting Diode (LED) light qualities (wavelengths), including red LED (R), blue LED (B), red (70%) + blue (30%) LED (RB), and white LED (W), on the wounding response in Arabidopsis thaliana. The majority of differentially expressed proteins were unique to each light condition. The highest (54%) and the lowest (22%) changes in total protein expression were observed in plants exposed to RB and B light, respectively. In wounded plants exposed to red + blue LED (RB) light, expression of antioxidant enzymes and a number of proteins related to dark reaction of photosynthesis decreased while the abundance of several proteins involved in the resistance to pathogen and lignin biosynthesis increased. Under blue LED (B) light, plants responded to wounding mainly through cell wall modification, biosynthesis of lignin and over expression of glutathione peroxidase. The results also indicated enhanced antioxidative capacity in response to wounding under red LED (R) light as compared to the other LED light conditions. The analyses of hormone metabolism suggested an increase in gibberellic acid (GA), abscisic acid (ABA) and salicylic acid (SA) signaling in the red + blue LED (RB), an enhancement in ethylene biosynthesis in the red LED (R), and increased jasmonic acid (JA) and brassinosteroid (BR) biosynthesis in the white LED (W) light conditions in response to wounding. Consistent with proteomic results related to JA metabolism, the highest concentration of methyl jasmonate (MeJA) was detected in white LED exposed plants. Late induction of JA biosynthesis-associated genes (AOC and AOS) in response to wounding was observed in all LED conditions, with the highest intensity in W light exposed plants. Collectively, we conclude that although white LED (W) light induces JA signaling pathway, red + blue LED (RB) light condition provides a better capability to recover from wound stress in A. thaliana. The results of H2O2 detection between different LED exposed plants showed different amounts of hydrogen peroxide production in response to wounding suggesting the possible signaling role of ROS in light-induced wound responses.