Cold acclimation triggers lipidomic and metabolic adjustments in the spotted wing drosophila Drosophila suzukii (Matsumara)
Résumé
Chronic cold exposure is detrimental to chill susceptible insects that may accumulate chill injuries. To cope with deleterious effects of cold temperature, insects employ a variety of physiological strategies and metabolic adjustments, such as production of cryoprotectants, or remodeling of cellular membranes. Cold tolerance is a key element determining the fundamental niche of species. Because Drosophila suzukii is an invasive fruit pest, originating from East Asia, knowledge about its thermal biology is urgently needed. Physiological mechanisms underlying cold tolerance plasticity remain poorly understood in this species. Here, we explored metabolic and lipidomic modifications associated with the acquisition of cold tolerance in D. suzukii using Omics technologies (LC- and GC-MS/MS). In both cold-acclimated males and females, we observed physiological changes consistent with homeoviscous/homeophasic adaptation of membranes: reshuffling of phospholipid headgroups and increasing unsaturation rate of fatty acids. Modification of fatty acids unsaturation were also observed in triacylglycerides, whichwould likely increase accessibility of lipid reserves. At the metabolic level, we observed clear-cut differentiation of metabolic profiles withcold-acclimated metabotypes showing accumulation of several potential cryoprotectants (sugars and amino acids). Metabolic pathwayanalyses indicated a remodeling of various processes, including purine metabolism and aminoacyl tRNA biosynthesis. These data provide alarge-scale characterization of lipid rearrangements and metabolic pathway modifications in D. suzukii in response to cold acclimationand contribute to characterizing the strategies used by this species to modulate cold tolerance.