Concomitant phytonutrient and transcriptome analysis of mature fruit and leaf tissues of tomato (Solanum lycopersicum L. cv. Oregon Spring) grown using organic and conventional fertilizer

Chemical composition, minerals concentration, total phenolic compounds, flavonoids content and antioxidant capacity in organic and conventional vegetables

The demand for organic vegetables is increasing worldwide, which has led to the growth of organic agriculture. However, information on chemical composition and antioxidant activity in vegetables grown organically under controlled conditions remains uncertain. For this study, 3 vegetables widely consumed in Brazil were cultivated in controlled organic and conventional cultivation systems: lettuce, coriander and tomato. Their chemical composition, mineral concentration, phenolic compound content, flavonoids and antioxidant activity (AA) were evaluated. The analyses of chemical and mineral composition revealed differences between the cultivation systems. Organic lettuce presented higher content of ashes, calcium and potassium. A higher content of phenolic compounds and flavonoids was observed in most organic vegetables. Using the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) assay, the organic tomato exhibited higher AA compared to conventional, while the ferric-reducing antioxidant power (FRAP) method showed higher AA for organic coriander and tomato than theirs conventional version. The correlation between bioactive compounds and AA was positive, higher and stronger for organic vegetables, considering phenolic compounds (including flavonoids) and DPPH or FRAP antioxidant activity. Principal Component Analysis (PCA) disclosed that organic lettuce and coriander were grouped according bioactive components. In general, organic vegetables showed better results for bioactive compounds and antioxidant activity.

Integrative analysis of the effects of organic and conventional farming methods on peanut based on transcriptome and metabolomics

To elucidate the nutritional quality of peanut under different farming methods, we selected two cultivars, "jihua13" and "jihua4", to grow in organic and conventional environments, respectively. After harvest, we measured physiological parameters and differential metabolites. Metabolomics showed that most of the amino acids, carbohydrates, and secondary metabolites in organically grown jihua4 were downregulated, which was completely the opposite in jihua13. Fatty acids associated with heart disease and hypertension are reduced in organically grown peanuts. In particular, the highly statistically significant tryptophan betaine seems to be used as a reference to distinguish between organic and conventional cultivation. Mechanisms leading to differences in crop chemical composition are explained by transcriptome analysis. The results of the transcriptome analysis indicated that organic cultivation largely affects the synthesis of amino acids and carbohydrates in jihua13. Combined analysis of transcriptome and metabolomics found that variety jihua13 is more sensitive to farming methods and produces more unsaturated fatty acids than jihua4.

Impact of heat stress, water stress, and their combined effects on the metabolism and transcriptome of grape berries

Recurring heat and drought episodes present challenges to the sustainability of grape production worldwide. We investigated the impacts of heat and drought stress on transcriptomic and metabolic responses of berries from two wine grape varieties. Cabernet Sauvignon and Riesling grapevines were subjected to one of four treatments during early fruit ripening: (1) drought stress only, (2) heat stress only, (3) simultaneous drought and heat stress, (4) no drought or heat stress (control). Berry metabolites, especially organic acids, were analyzed, and time-course transcriptome analysis was performed on samples before, during, and after the stress episode. Both alone and in conjunction with water stress, heat stress had a much more significant impact on berry organic acid content, pH, and titratable acidity than water stress. This observation contrasts with previous reports for leaves, which responded more strongly to water stress, indicating that grape berries display a distinct, organ-specific response to environmental stresses. Consistent with the metabolic changes, the global transcriptomic analysis revealed that heat stress had a more significant impact on gene expression in grape berries than water stress in both varieties. The differentially expressed genes were those associated with the tricarboxylic acid cycle and glyoxylate cycle, mitochondrial electron transport and alternative respiration, glycolysis and gluconeogenesis, carbohydrate allocation, ascorbate metabolism, and abiotic stress signaling pathways. Knowledge regarding how environmental stresses, alone and in combination, impact the berry metabolism of different grape varieties will form the basis for developing recommendations for climate change mitigation strategies and genetic improvement.

Cytoprotective and Antigenotoxic Properties of Organic vs. Conventional Tomato Puree: Evidence in Zebrafish Model

In this in vivo study, we investigated cytoprotective and antigenotoxic effects of commercial tomato puree obtained from conventional vs. organic farming systems (pesticides vs. pesticide-free agriculture, respectively). This is relevant as pesticides are widely used in agriculture to prevent pests, weeds, and the spread of plant pathogens. By exposing zebrafish to tomato puree alone and in combination with H2O2 (a well-known genotoxic agent), we analyzed the percentage of fish survival, cell viability, intracellular concentration of reactive oxygen species (ROS), DNA fragmentation index (DFI%), and genomic template stability (GTS%). Fish exposed to organic puree showed higher fish survival and cellular viability, lower DFI% and ROS, and improved GTS%. Our results suggest a higher cytoprotective and antigenotoxic effect of organic pesticide-free tomatoes, probably because the activity of natural phytochemicals is not affected by the presence of toxic residues, which are otherwise produced by pesticides used in conventional farming systems. Our study points out the importance of considering alternative strategies in agriculture to minimize the genotoxic impact of chemical pesticides.

The Fruit Proteome Response to the Ripening Stages in Three Tomato Genotypes

The tomato is a horticultural crop that appears in various colors as it ripens. Differences in the proteome expression abundance of a tomato depend on its genotype and ripening stage. Thus, this study aimed to confirm the differences in changes in the proteome according to four ripening stages (green, breaker, turning, and mature) of three tomato genotypes, i.e., yellow, black, and red tomatoes, using a gel-based proteomic technique. The number of protein spots shown as two-dimensional electrophoresis (2-DE) gels differed according to tomato genotype and ripening stage. A total of 286 variant proteins were determined using matrix-assisted laser desorption-time of flight (MALDI-TOF) mass spectrometry (MS) analysis, confirming 233 identified protein functions. In three tomato genotypes in each ripening stage, grouping according to the Munich Information Center for Protein Sequences (MIPS) functional categories confirmed the variant proteins involved in the following: energy processes (21%); metabolism (20%); protein fate (15%); protein synthesis (10%); a protein with a binding function or cofactor requirement (8%); cell rescue, defense, and virulence (8%); cellular transport, transport facilitation, and transport routes (6%); the biogenesis of cellular components (5%); cell cycle and DNA processing (2%); others (5%). Among the identified protein spots in the function category, two proteins related to metabolism, four related to energy, four related to protein synthesis, and two related to interaction with the cellular environment showed significantly different changes according to the fruit color by the ripening stage. This study reveals the physiological changes in different types of tomatoes according to their ripening stage and provides information on the proteome for further improvement.

Biochar—A Panacea for Agriculture or Just Carbon?

The sustainable production of food faces formidable challenges. Foremost is the availability of arable soils, which have been ravaged by the overuse of fertilizers and detrimental soil management techniques. The maintenance of soil quality and reclamation of marginal soils are urgent priorities. The use of biochar, a carbon-rich, porous material thought to improve various soil properties, is gaining interest. Biochar (BC) is produced through the thermochemical decomposition of organic matter in a process known as pyrolysis. Importantly, the source of organic material, or ‘feedstock’, used in this process and different parameters of pyrolysis determine the chemical and physical properties of biochar. The incorporation of BC impacts soil–water relations and soil health, and it has been shown to have an overall positive impact on crop yield; however, pre-existing physical, chemical, and biological soil properties influence the outcome. The effects of long-term field application of BC and how it influences the soil microcosm also need to be understood. This literature review, including a focused meta-analysis, summarizes the key outcomes of BC studies and identifies critical research areas for future investigations. This knowledge will facilitate the predictable enhancement of crop productivity and meaningful carbon sequestration.