Integrating proteomics and metabolomics approaches to elucidate the ripening process in white Psidium guajava.

Psidium guajava (guava) exhibits a high content of biomolecules with nutraceutical properties. However, the biochemistry and molecular foundation of guava ripening is unknown. We performed comparative proteomics and metabolomics studies in different fruit tissues at two ripening stages to understand this process in white guava. Our results, suggest the positive contribution of ethylene and abscisic acid (ABA) signaling to the regulation of biochemical changes during guava ripening. We characterized the modulation of several metabolic pathways, including those of sugar and chlorophyll metabolism, abiotic and biotic stress responses, and biosynthesis of carotenoids and secondary metabolites, among others. In addition to ethylene and ABA, we also found a differential accumulation of other growth regulators such as brassinosteroids, cytokinin, methyl-jasmonate, gibberellins and proteins, and discuss their possible implications in the intricate biochemical network associated with guava ripening process. This integrative approach represents a global overview of the metabolic pathway dynamics during guava ripening.

A First Glimpse of the Mexican Fruit Fly Anastrepha ludens (Diptera: Tephritidae) Antenna Morphology and Proteome in Response to a Proteinaceous Attractant.

Anastrepha ludens is a key pest of mangoes and citrus from Texas to Costa Rica but the mechanisms of odorant perception in this species are poorly understood. Detection of volatiles in insects occurs mainly in the antenna, where molecules penetrate sensillum pores and link to soluble proteins in the hemolymph until reaching specific odor receptors that trigger signal transduction and lead to behavioral responses. Scrutinizing the molecular foundation of odorant perception in A. ludens is necessary to improve biorational management strategies against this pest. After exposing adults of three maturity stages to a proteinaceous attractant, we studied antennal morphology and comparative proteomic profiles using nano-LC-MS/MS with tandem mass tags combined with synchronous precursor selection (SPS)-MS3. Antennas from newly emerged flies exhibited dense agglomerations of olfactory sensory neurons. We discovered 4618 unique proteins in the antennas of A. ludens and identified some associated with odor signaling, including odorant-binding and calcium signaling related proteins, the odorant receptor co-receptor (Orco), and putative odorant-degrading enzymes. Antennas of sexually immature flies exhibited the most upregulation of odor perception proteins compared to mature flies exposed to the attractant. This is the first report where critical molecular players are linked to the odor perception mechanism of A. ludens.