Proteomic and Low-Polar Metabolite Profiling Reveal Unique Dynamics in Fatty Acid Metabolism during Flower and Berry Development of Table Grapes.

Grapevine development and ripening are complex processes that involve several biochemical pathways, including fatty acid and lipid metabolism. Fatty acids are essential components of lipids, which play crucial roles in fruit maturation and flavor development. However, the dynamics of fatty acid metabolism in grape flowers and berries are poorly understood. In this study, we present those dynamics and investigate the mechanisms of fatty acid homeostasis on 'Thompson Seedless' berries using metabolomic and proteomic analyses. Low-polar metabolite profiling indicated a higher abundance of fatty acids at the pre-flowering and pre-veraison stages. Proteomic analyses revealed that grape flowers and berries display unique profiles of proteins involved in fatty acid biosynthesis, triacylglycerol assembly, fatty acid ß-oxidation, and lipid signaling. These findings show, for the first time, that fatty acid metabolism also plays an important role in the development of non-oil-rich tissues, opening new perspectives about lipid function and its relation to berry quality.

Proteomic and metabolomic integration reveals the effects of pre-flowering cytokinin applications on central carbon metabolism in table grape berries.

Consumers around the world prefer high quality table grapes. To achieve higher quality traits at ripening, grapevine producers apply different plant growth regulators. The synthetic cytokinin forchlorfenuron N-(2-chloro-4-pyridinyl)-N'-phenylurea (CPPU) is widely used, its effect on grape quality is poorly understood. We hypothesized that the use of CPPU in pre-flowering can lead to changes in the metabolism that affects grape quality at harvest. Therefore, we investigated the role of CPPU applications on the quality of grapes by integrating proteomics and metabolomics. CPPU-treated grapevines showed a significant increase in berry size and firmness. Proteomic analyses indicated that CPPU-treated berries accumulated enzymes associated with carbohydrate metabolism, glycolysis, and tricarboxylic acid (TCA) cycle at harvest. Metabolomic analyses showed shifts in the abundance of compounds associated with carbohydrate metabolism and TCA cycle in CPPU-treated grapes. These findings suggest that CPPU applications modulate central carbon metabolism, improving grape berry quality.

A multiomics integrative analysis of color de-synchronization with softening of 'Hass' avocado fruit: A first insight into a complex physiological disorder.

Exocarp color de-synchronization with softening of 'Hass' avocado is a relevant recurrent problem for the avocado supply chain. This study aimed to unravel the mechanisms driving this de-synchronization integrating omics datasets from avocado exocarp of different storage conditions and color phenotypes. In addition, we propose potential biomarkers to predict color synchronized/de-synchronized fruit. Integration of transcriptomics, proteomics and metabolomics and network analysis revealed eight transcription factors associated with differentially regulated genes between regular air (RA) and controlled atmosphere (CA) and twelve transcription factors related to avocado fruit color de-synchronization control in ready-to-eat stage. CA was positively correlated to auxins, ethylene, cytokinins and brassinosteroids-related genes, while RA was characterized by enrichment of cell wall remodeling and abscisic acid content associated genes. At ready-to-eat higher contents of flavonoids, abscisic acid and brassinosteroids were associated with color-softening synchronized avocados. In contrast, de-synchronized fruit revealed increases of jasmonic acid, salicylic acid and auxin levels.

Proteomic analysis of mashua (Tropaeolum tuberosum) tubers subjected to postharvest treatments.

Mashua (Tropaeolum tuberosum) is an important food in certain areas of the Andean region, where it is popularly believed to possess medicinal properties. Several studies have previously shown the potential of this tuber as a source of bioactive compounds. Traditionally, the tuber is exposed to the sun before consumption, in order to reduce its bitterness. The present work aims to study, at the proteome level, the differential abundance of proteins in tubers subjected to different postharvest treatments: sun-exposure (SUN), shade (SHA), refrigeration (COLD) and shade combined with sun-exposure (SHA-SUN) compared to recently harvested tubers (INIT). Results showed that sun exposure for prolonged times (9 days) resulted in increased abundance of proteins classified as heat shock proteins, intracellular traffic, disease/defense and protein degradation. Our results reflect that the sun treatment activates defense systems and osmoprotection adjustment against water loss and reactive oxygen species.

Integration of proteomics and metabolomics data of early and middle season Hass avocados under heat treatment.

Ripening heterogeneity of Hass avocados results in inconsistent quality fruit delivered to the triggered and ready to eat markets. This research aimed to understand the effect of a heat shock (HS) prior to controlled atmosphere (CA) storage on the reduction of ripening heterogeneity. HS prior to CA storage reduces more drastically the ripening heterogeneity in middle season fruit. Via correlation network analysis we show the different metabolomics networks between HS and CA. High throughput proteomics revealed 135 differentially expressed proteins unique to middle season fruit triggered by HS. Further integration of metabolomics and proteomics data revealed that HS reduced the glycolytic throughput and induced protein degradation to deliver energy for the alternative ripening pathways. l-isoleucine, l-valine, l-aspartic and ubiquitin carboxyl-terminal hydrolase involved in protein degradation were positively correlated to HS samples. Our study provides new insights into the effectiveness of HS in synchronizing ripening of Hass avocados.