Synthesis Of Phenolic Compounds Research Articles

Depolymerization of Lignosulfonate Catalyzed by Different Solid Base Oxides to Prepare Phenolic Compounds

Lignin is the most abundant aromatic renewable polymer in nature. However, its very stable structure limits its widespread application. To achieve high-value utilization of lignin, this study used solid base oxides to depolymerize calcium lignosulfonate (CLS) for the synthesis of phenolic compounds. The catalyst precursors were prepared by hydrothermal synthesis, and the corresponding mesoporous metal oxides NiO, MgCoOx, and NiMgCoOx were obtained after calcination. MgCoOx and NiMgCoOx had similar but stronger basicity compared to NiO. While all oxides promoted the depolymerization of CLS, NiMgCoOx was identified as the best catalyst, achieving a maximum liquid product yield of 74.3 wt.% and a selectivity of phenolic compounds of 74.52% in the liquid product. In addition, NiMgCoOx showed satisfactory structural and catalytic stability. The experimental results indicated that solid base oxides can capture the active hydrogen in CLS, causing the hydrolysis reaction of ether bonds, and the resulting products continuously depolymerize or polymerize; Co present in the catalyst promotes the adsorption of hydrogen by Ni, while NiO in NiMgCoOx facilitates the adsorption of both reactants and hydrogen. The combination of Ni and Co improves hydrogenation performance.

Relationships Between Photosynthetic Efficiency and Grain Antioxidant Content of Barley Genotypes Under Increasing Nitrogen Rates

Nitrogen fertilization may affect the functioning of photosynthesis as well as the chemical composition and antioxidant potential of cereal grains. Little is known about the relationship between the efficiency of photosynthesis and the content of phenolic compounds in barley grain, especially in conditions of varying nitrogen availability. In this regard, a field experiment was conducted to examine the responses of two primary barley genotypes with elevated phenolic compound content (TPC) in grain and an intensive modern cultivar H. v. vulgare with high protein content to increasing nitrogen fertilization (rates of 0, 30, 60 and 90 kg N ha−1) during the study years, which differed in terms of hydrothermal conditions. The leaf greenness index (SPAD) and chlorophyll fluorescence parameters were evaluated on three occasions throughout the growing season. Following the harvest, the chemical composition of the grains, including phenolic acids, flavonoids and antioxidant potential, was evaluated. The antioxidant potential and chemical composition of the grain, including TPC and protein content, depended to the greatest extent on genetic and environmental factors, and only then on nitrogen fertilization. Nitrogen increased the TPC content and antioxidant capacity ABTS+ of the grains of all studied genotypes and the protein content in H. v. vulgare grain. Rates of 60 and 90 kg N ha−1 resulted in a significant increase in the SPAD, PIabs and Fv/Fm in BBCH 34 and 57. A positive correlation was confirmed between the SPAD and PIabs and the content of TPC and ABTS+ in the grain. The dependence of qualitative characteristics on the Fv/Fm was also demonstrated. The primary genotypes are characterized by a greater genetic potential for the synthesis of phenolic compounds than the modern cultivar H. v. vulgare. The synthesis of phenolic compounds, and thus their accumulation in the grain, is clearly stimulated by unfavorable environmental factors and moderate nitrogen rates and depends on the chlorophyll content in the leaves and the efficiency of photosynthesis. N fertilization has a beneficial effect on the content of phenolic compounds in grain resulting from the improvement in the SPAD and PIabs. The chemical composition of grain and the increase in antioxidant potential are determined by the Fv/Fm, which is low under hydrothermal stress conditions.

Seasonal influence on tomato fruit metabolome profile: Implications for ABA signaling in multi-stress resilience

The increasing effects of climate change are leading to an increase in the number and intensity of extreme events, making it essential to study how plants respond to various stresses occurring simultaneously. A crucial regulator of plant responses to abiotic stress is abscisic acid (ABA), as its accumulation in response to stress leads to transcriptomic and metabolomic changes that contribute to plant stress tolerance. In the present study, we investigated how ABA, stress conditions (salinity, water deficit and their combination) and seasons (autumn-winter and spring-summer) regulate tomato fruit yield and metabolism using tomato wild type (WT) and the ABA-deficient flacca mutant (flc) under stress conditions in cold and warm seasons. Our results showed that the applied stresses did not have the same effect in the warm season as in the cold season. In WT plants, the levels of other flavonoids, lignans and other polyphenols were higher in summer fruits, whereas the levels of anthocyanins, flavanols, flavonols, phenolic acids and stilbenes were higher in winter fruits. Furthermore, the significant increase in anthocyanins and flavonols was associated with the combination of salinity + water deficit in both seasons. Additionally, under certain conditions, flc mutants showed an enrichment of the superclasses of benzenoids and organosulphur compounds. The synthesis of phenolic compounds in flc fruits was also significantly different compared to WT plants. Thus, the metabolic profile of tomato fruits varies significantly with endogenous ABA levels, season of cultivation and applied stress treatments, highlighting the multifactorial nature of plant responses to combined environmental factors.

Transcriptome analysis reveals biosynthesis and regulation of flavonoid in common bean seeds during grain filling

The Andean domesticated common beans (Phaseolus vulgaris) are significant sources of phenolic compounds associated with health benefits. However, the regulation of biosynthesis of these compounds during bean seed development remains unclear. To elucidate the gene expression patterns involved in the regulation of the flavonoid pathway, we conducted a transcriptome analysis of two contrasting Chilean varieties, Negro Argel (black bean) and Coscorron (white bean), at three developmental stages associated with seed color change, as well as different flavonoid compound accumulations. Our study reveals that phenolic compound synthesis initiates during seed filling, although it exhibits desynchronization between both varieties. We identified 10,153 Differentially Expressed Genes (DEGs) across all comparisons. The KEGG pathway ‘Flavonoid biosynthesis’ showed enrichment of induced DEGs in Negro Argel (PV172), consistent with the accumulation of delphinidin, petunidin, and malvidin hexosides in their seeds, while catechin glucoside, procyanidin and kaempferol derivatives were predominantly detected in Coscorrón (PV24). Furthermore, while the flavonoid pathway was active in both varieties, our results suggest that enzymes involved in the final steps, such as ANS and UGT, were crucial, inducing anthocyanin formation in Negro Argel. Additionally, during active anthocyanin biosynthesis, the accumulation of reserve proteins or those related to seed protection and germination was induced. These findings provide valuable insights and serve as a guide for plant breeding aimed at enhancing the health and nutritional properties of common beans.

Exogenous p-coumaric acid treatment improves phenolic compounds biosynthesis of postharvest cherry tomatoes by regulating physiological metabolism.

To investigate the effect of p-coumaric acid (p-CA) on postharvest cherry tomatoes, breaker stage fruits were treated with p-CA to analyze the physiological metabolism during storage. The results showed that exogenous p-CA treatment improved the sensory quality of tomato fruits. Transcriptomics results indicated that 782 genes (339 up-regulated and 443 down-regulated) were differentially expressed between p-CA treated and control fruits. Results suggested that p-CA treatment regulated the synthesis of phenolic compounds and inhibited the fruit ripening through the pathways of mangiferic acid biosynthesis and phenylalanine metabolism. Key enzymes activities of the phenylpropane metabolic pathway of tomato fruits were increased, including phenylalanine ammonia lyase (PAL), cinnamic acid 4-hydroxylase (C4H), and 4-coumarate-CoA ligase (4CL). In addition, the total phenols content, flavonoids content and antioxidant capacities of tomato fruits were improved with p-CA treatment. Overall, these findings showed that p-CA treatment could be a potential strategy for fruit and vegetable preservation.

Effects of grapevine canopy leaning on grape composition and wine quality of ‘Bobal’

Exploring new field strategies for adapting winegrowing regions to the adverse effects of climate change becomes imperative. This study focuses on the effects of canopy architecture through the trellis systems leaning of North–South oriented vineyard’s rows vertical shoot positioned (VSP) system by 30° towards either the East (ESP) or the West (WSP) as a possible adaptation technique. The trial was conducted over two seasons in a Vitis vinifera L. cv. Bobal vineyard located in Requena (Valencia), eastern Spain, under a temperate-warm climate. The canopy leaning was considered to affect the radiation load and its timing with potential effects on vine physiology and grape metabolism and, consequently, on grape and wine quality. Leaning treatments affected vegetative growth, likely due to slight differences in vine water status. In comparison to VSP and ESP, WSP intercepts more light in the morning, when the photosynthetic capacity of the vines is at its highest. However, this results in a more negative vine water potential, which in turn leads to a reduction in vigour with no impact on yield. Musts from the WSP showed a tendency to increase total acidity compared to VSP, while ESP tended to decrease it. This was likely due to the reduction in temperature within the cluster microclimate in WSP in comparison to the ESP and VSP treatments. In addition, musts from the WSP treatment showed higher colour intensity, anthocyanins and polyphenols, potentially attributable to its more negative potentials, likely due to its more negative potentials, which may have prompted the synthesis of phenolic compounds. Consequently, wines from the WSP treatment displayed higher total acidity and lower pH, as well as higher colour intensity, anthocyanins, and polyphenolic content. In addition, WSP wines had higher concentrations of esters and higher alcohols. The improvements in grape and wine composition are likely due to an increased cluster radiation interception in the morning and reduced heating in the afternoon when VPD is higher. Our findings demonstrate that canopy management by leaning VSP vines towards the West can be a useful technique for adapting grape and wine composition to climate change and provide insights into its physiological basis.

The ERF transcription factor SlERF7 promotes UV-C-induced biosynthesis of phenolic compounds in tomato

In this study, the molecular pathways of SlERF7 in regulating the synthesis and accumulation of phenolic compounds induced by postharvest UV-C in tomato fruit was deeply investigated by constructing transgenic plants. The findings revealed a pronounced induction of phenolic compounds accumulation following UV-C irradiation, coupled with heightened activities of PAL, 4CL, C4H, CHS, and CHI enzymes, alongside upregulated expression levels of SlPAL5, SlC4H, Sl4CL, SlCHS2, and SlCHI within SlERF7 overexpressed fruit. Conversely, SlERF7 knockout fruit exhibited diminished levels of phenolic compounds, enzyme activities, and gene expression after UV-C irradiation. Furthermore, subcellular localization analysis showed that SlERF7 was localized in the nucleus. Dual luciferase assay and electrophoretic mobility shift assay (EMSA) indicated that SlERF7 directly bound to the GCC-box in the SlPAL5 promoter and activated its transcriptional activity. Therefore, it was confirmed that SlERF7 might positively promote UV-C-induced phenolic biosynthesis in postharvest tomato fruit by targeting the promoter of SlPAL5.

Effect of Agitation and Temporary Immersion on Growth and Synthesis of Antibacterial Phenolic Compounds in Genus Drosera.

Sundews (Drosera sp.) are the source of biologically active secondary metabolites: phenolic acids, flavonoids, and 1,4-naphtoquinones. Because obtaining them from the natural environment is impossible (rare and endangered species), in this study modifications of traditional tissue cultures grown in solid medium (SM), such as agitated cultures (ACs) (cultures in liquid medium with rotary shaking) and temporary immersion bioreactors PlantformTM (TIB), were used for multiplication of four sundew species: Drosera peltata, Drosera indica, Drosera regia, and Drosera binata, with simultaneously effective synthesis of biologically active phenolic compounds. Each species cultivated on SM, AC, and TIB was tested for biomass accumulation, the content of total phenols and selected phenolic derivative concentrations (DAD-HPLC), the productivity on of phenolic compounds, as well as its antibacterial activity against two human pathogens: Staphylococcus aureus and Escherichia coli. The results showed that the type of culture should be selected for each species separately. Phytochemical analyses showed that the synthesis of secondary metabolites from the groups of phenolic acids, flavonoids, and 1,4-naphthoquinones can be increased by modifying the cultivation conditions. D. regia turned out to be the richest in phenolic compounds, including 1,4-naphtoquinones: plumbagin and ramentaceone. Extracts from D. indica and D. regia tissue showed strong antibacterial activity against both pathogens. It has also been shown that the growth conditions of sundews can modify the level of secondary metabolites, and thus, their biological activity.

Wounding Citrus Peel By-Products as Abiotic Stress to Induce the Synthesis of Phenolic Compounds?

Wounding stress stimulates secondary metabolism and induces the phytochemical accumulation of fresh-cut fruit and vegetables. This research aims to study the biosynthesis of secondary metabolites in citrus peel by-products after different wounding intensities. Orange, grapefruit, and lemon peels were cut into rectangular shapes of 8.5 × 2 cm (CTRL), 1 × 1 cm dices (D), and 0.25 cm grates (G). Samples were stored at 15 °C and 65% relative humidity. Their total phenolic content (TPC), total antioxidant capacity (TAC), and individual organic and phenolic compounds were analyzed after 0, 4, 8, 24, 28, and 36 h. The results showed that the metabolite content decreased with the incubation time, so it is recommended to sample by-products between the first 8 h to achieve the maximum content. Grating, the most severe abiotic stress, was not a suitable technique to induce the synthesis of biocompounds because it allowed the full recovery of flavedo, but partial of albedo. However, it was different for CTRL and D, whose TPCs were ~170 and ~200%, ~98 and ~78%, and ~8 and ~36% higher for orange, grapefruit, and lemon, respectively, compared to G. A principal component analysis confirmed differences between the fruit species and cutting shapes combining all factors. Wounding citrus peels induces the accumulation of phytochemical compounds, but the layer of peel recovered in the cut is crucial in the concentration of phytochemicals extracted. It could be an innovative tool to revalorize these inedible parts of citrus, but further research is still needed.

Agitated and temporary immersion bioreactor cultures of Reynoutria japonica Houtt. as a rich source of phenolic compounds

Reynoutria japonica Houtt. (Japanese knotweed) is an invasive plant belonging to the Polygonaceae family. However, being native to East Asia, it has been used in natural medicine for ages because of its broad range of biological activity. Although R. japonica is known as a rich source of phenolic compounds, plant biomass collected from the field may be contaminated with toxic elements like heavy metals, and the level of metabolite accumulation depends on environmental conditions. Therefore, the aim of this study was to derive Japanese knotweed tissue cultures and investigate biomass production and phenolic compound synthesis in in vitro conditions. Plants were cultivated in a traditional agar-solidified medium, in a liquid medium with rotary shaking (agitated culture), and in a temporary immersion bioreactors Plantform™, as well as in soil (ex vitro conditions). Analyses of the growth index and dry weight accumulation were performed on the collected material. In the extracts obtained from examined plants, qualitative and quantitative analysis of phenolic derivatives using DAD-HPLC was conducted to determine the sum of phenolic compounds, as well as the quantity of selected phenolic acids, catechins, and other flavonoids. Results have shown that agitated cultures and temporary immersion bioreactors increased biomass accumulation compared to solid medium cultures. Tissue cultures of R. japonica had increased synthesis of phenolic compounds compared to plants from ex vitro conditions. Shoots and roots from agitated cultures were 2.8- and 3.3-fold richer in catechins, respectively, compared to plants cultivated in soil. Based on the obtained results it can be concluded that agitated and bioreactor cultures are the best source of Japanese knotweed biomass rich in valuable secondary metabolites.

Stress response in tomato as influenced by repeated waterlogging.

Plants respond to water stress with a variety of physiological and biochemical changes, but their response varies among species, varieties and cultivars. Waterlogging in tomato reduces plant growth, degrade chlorophyll and increase concentration of oxidative parameters. Priming can alleviate stress in plants caused by waterlogging enabling plants to be more tolerant to an additional stress in the current or even subsequent generation. The aim of this study was to evaluate tomato genotypes for their sensitivity to waterlogging stress applied during early vegetative growth and at full flowering stage. The study included two local genotypes, Trebinjski sitni (GB1126) and Žuti (GB1129), and the reference variety Novosadski jabučar (NJ), which is the variety most commonly used in Serbia and Bosnia and Herzegovina. The activity of class III peroxidase (POX), hydrogen peroxide (H2O2) content and malondialdehyde (MDA) content were measured spectrophotometrically, and for quantification of individual phenolic compounds, targeted approach was adopted, using UHPLC/DAD/(-)HESI-MS2 instrument (Dionex UltiMate 3000 UHPLC system with a DAD detector, configured with a triple quadrupole mass spectrometer TSQ Quantum Access Max (Thermo Fisher Scientific, Germany)). Oxidative parameters (H2O2 and MDA) exhibited an increase in content in leaves of tomato plants that underwent waterlogging stress compared to control plants. Moreover, oxidative parameters showed positive correlation with proteins and phenolics content. The obtained correlations can indicate that one of the response strategies of tomato plants to waterlogging is the increased synthesis of proteins and phenolic compounds. The POX activity was not correlated with other parameters except with the polyphenols. A positive correlation was shown between POX activity and the content of phenolic compounds, indicating their independent roles in the removal of ROS. Changes in the phenolic profiles after the exposure of plants to waterlogging stress are recorded, and these changes were more severe in leaves and fruits of GB1129 and NJ genotypes than in GB1126. Thus, genotype GB1126 is the most efficient in maintaining the phenolic profiles of leaves and fruits, and therefore of the nutritive and organoleptic qualities of fruits following the exposure to waterlogging. Also, genotype GB1126 exhibited the ability to maintain the content of oxidative parameters during waterlogging at certain growth stages, implying certain waterlogging tolerance. Waterlogging triggered stress memory but not at all growth stages. The most pronounced stress memory was obtained in fruit samples in the phase of full fruit maturity on the 1st truss. This study shed light on the defense mechanisms of tomato plants to repeated waterlogging stress from the perspectives of the changes in the composition of major phenolics, and pointed to the 5-O-caffeoylquinic acid and rutin as the chemical markers of the waterlogging stress tolerance in tomato. However, it remains to be determined whether this modulation has a positive or negative effect on the overall plant metabolism. Further investigations are needed to fully elucidate the benefits of waterlogging pretreatment in this context.

Maintenance of post-harvest antioxidant quality in ‘Niagara Rosada’ grape using salicylic acid

Salicylic acid is a plant growth regulator used in grapes to maintain postharvest quality. ‘Niagara Rosada’, a table grape, although much appreciated for its flavor, has a short shelf life. We evaluated the influence of postharvest application of different doses of salicylic acid on the quality of ‘Niagara Rosada’ after harvest in an effort to control rates of berry drop and decay, as well as to maintain the quality of grape bunches during refrigerated storage. Freshly harvested bunches of ‘Niagara Rosada’ (Vitis labrusca x V. vinifera) were immersed in salicylic acid solutions at concentrations of 0.0, 0.28, 0.55, 0.83, and 1.10 g L-1, and then refrigerated (5 ± 1 °C and 95 ± 5 % RH) for 20 days. Physical and chemical analyses of grapes were performed at 5-day intervals. Salicylic acid maintained the postharvest quality of ‘Niagara Rosada’ grapes throughout storage. The lowest concentration of salicylic acid (0.28 g L-1) effectively induced the synthesis of phenolic compounds and improved the antioxidant capacities of both grapes and stems. High levels of salicylic acid (0.83 and 1.10 g L-1) resulted in an increase in anthocyanin content in fruit and enzyme activities (peroxidase and superoxide dismutase) in stems, enhancing conservation and reducing levels of decay and berry drop.

Identification of mungbean yellow mosaic India virus and susceptibility-related metabolites in the apoplast of mung bean leaves.

The investigation of MYMIV-infected mung bean leaf apoplast revealed viral genome presence, increased EVs secretion, and altered stress-related metabolite composition, providing comprehensive insights into plant-virus interactions. The apoplast, an extracellular space around plant cells, plays a vital role in plant-microbe interactions, influencing signaling, defense, and nutrient transport. While the involvement of apoplast and extracellular vesicles (EVs) in RNA virus infection is documented, the role of the apoplast in plant DNA viruses remains unclear. This study explores the apoplast's role in mungbean yellow mosaic India virus (MYMIV) infection. Our findings demonstrate the presence of MYMIV genomic components in apoplastic fluid, suggesting potential begomovirus cell-to-cell movement via the apoplast. Moreover, MYMIV infection induces increased EVs secretion into the apoplast. NMR-based metabolomics reveals altered metabolic profiles in both apoplast and symplast in response to MYMIV infection, highlighting key metabolites associated with stress and defense mechanisms. The data show an elevation of α- and β-glucose in both apoplast and symplast, suggesting a shift in glucose utilization. Interestingly, this increase in glucose does not contribute to the synthesis of phenolic compounds, potentially influencing the susceptibility of mung bean to MYMIV. Fructose levels increase in the symplast, while apoplastic sucrose levels rise significantly. Symplastic aspartate levels increase, while proline exhibits elevated concentration in the apoplast and reduced concentration in the cytosol, suggesting a role in triggering a hypersensitive response. These findings underscore the critical role of the apoplast in begomovirus infection, providing insights for targeted viral disease management strategies.

Interação fungicida-requeima na síntese de compostos fenólicos e atividade de enzimas de defesa em tomateiro

Due to the significant impact of late blight (LB) (Phytophthora infestans [Mont.]) on tomato (Solanum lycopersicum L.), we investigated the interaction between fungicides and this disease to understand how some plant defense mechanisms are affected over time. Following a randomized design, we evaluated the synthesis of phenolic compounds (PHE) and the activity of phenylalanine ammonium lyase (PAL), peroxidases (POX) and superoxide dismutase (SOD). The experiment involved the application of fosetyl-Al and fluoxastrobin (fungicides with dual modes of action) on healthy and infected tomato plants. LB severity was assessed weekly and leaf samples were collected at various intervals for biochemical analysis. The Kruskal-Wallis test (α = 0.05) analyzed main effects of infection, fungicide, and time on response variables, followed by Bonferroni post hoc for significant group differences and regression models to evaluate variable effects over time. The application of fungicides had no effect on enzymatic activity or PHE accumulation. While PAL and SOD activities were not significantly affected by infection, POX activity was significantly higher in healthy plants (4793.8 U g-1 fresh weight) compared to infected plants (1858.1 U g-1 fresh weight). A complex interaction between PHE accumulation in relation to LB severity and time was observed, with a notable increase in PHE levels at 50 days after transplant when disease severity was between 25 and 50%. Future studies should consider including a broader range of genotypes and isolates of P. infestans, a more extensive set of biochemical responses, and evaluations of the overexpression of genes related to plant defense.

The Influence of Zinc Oxide Nanoparticles and Salt Stress on the Morphological and Some Biochemical Characteristics of Solanum lycopersicum L. Plants.

Salinity reduces crop yields and quality, causing global economic losses. Zinc oxide nanoparticles (ZnO-NPs) improve plant physiological and metabolic processes and abiotic stress resistance. This study examined the effects of foliar ZnO-NPs at 75 and 150 mg/L on tomato Kecskeméti 549 plants to alleviate salt stress caused by 150 mM NaCl. The precipitation procedure produced ZnO-NPs that were characterized using UV-VIS, TEM, STEM, DLS, EDAX, Zeta potential, and FTIR. The study assessed TPCs, TFCs, total hydrolyzable sugars, total free amino acids, protein, proline, H2O2, and MDA along with plant height, stem width, leaf area, and SPAD values. The polyphenolic burden was also measured by HPLC. With salt stress, plant growth and chlorophyll content decreased significantly. The growth and development of tomato plants changed by applying the ZnO-NPs. Dosages of ZnO-NPs had a significant effect across treatments. ZnO-NPs also increased chlorophyll, reduced stress markers, and released phenolic chemicals and proteins in the leaves of tomatoes. ZnO-NPs reduce salt stress by promoting the uptake of minerals. ZnO-NPs had beneficial effects on tomato plants when subjected to salt stress, making them an alternate technique to boost resilience in saline soils or low-quality irrigation water. This study examined how foliar application of chemically synthesized ZnO-NPs to the leaves affected biochemistry, morphology, and phenolic compound synthesis with and without NaCl.

Spectroscopic Investigation of Tomato Seed Germination Stimulated by Trichoderma spp.

Seed germination is a complex process that can be negatively affected by numerous stresses. Trichoderma spp. are known as effective biocontrol agents as well as plant growth and germination stimulators. However, understanding of the early interactions between seeds and Trichoderma spp. remains limited. In the present paper, Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy were used to reveal the nature of tomato seed germination as stimulated by Trichoderma. A rapid response of tomato seeds to Trichoderma spp. was observed within 48 h on Murashige and Skoog medium (MS) substrate, preceding any physical contact. Raman analysis indicated that both Trichoderma species stimulated phenolic compound synthesis by triggering plant-specific responses in seed radicles. The impact of T. harzianum and T. brevicompactum on two tomato cultivars resulted in alterations to the middle lamella pectin, cellulose, and xyloglucan in the primary cell wall. The Raman spectra indicated increased xylan content in NA with T9 treatment as well as increased hemicelluloses in GZ with T4 treatment. Moreover, T4 treatment resulted in elevated conjugated aldehydes in lignin in GZ, whereas the trend was reversed in NA. Additionally, FTIR analysis revealed significant changes in total protein levels in Trichoderma spp.-treated tomato seed radicles, with simultaneous decreases in pectin and/or xyloglucan. Our results indicate that two complementary spectroscopic methods, FTIR and Raman spectroscopy, can give valuable information on rapid changes in the plant cell wall structure of tomato radicles during germination stimulated by Trichoderma spp.

The use of preharvest and postharvest treatments with salicylic acid to control brown rot and the response to its infection with the synthesis of phenolic compounds in peach fruit

The use of preharvest and postharvest treatments with salicylic acid to control brown rot and the response to its infection with the synthesis of phenolic compounds in peach fruit

Deciphering the Genetic Basis of Allelopathy in japonica Rice Cultivated in Temperate Regions Using a Genome-Wide Association Study

Allelopathy has been considered as a natural method of weed control. Despite the nature of allelochemical compounds has been studied, little is known about the genetic basis underlying allelopathy. However, it is known that rice exhibits diverse allelopathic potentials across varieties, and breeding for rice plants exhibiting allelopathic potential conferring an advantage against weeds in paddy fields would be highly desirable. Knowledge of the gene factors and the identification of the genomic regions responsible for allelopathy would facilitate breeding programs. Taking advantage of the existing genetic diversity in rice, particularly in temperate japonica rice, we conducted a comprehensive investigation into the genetic determinants that contribute to rice allelopathy. Employing Genome-Wide Association Study, we identified four Quantitative Trait Loci, with the most promising loci situated on chromosome 2 and 5. Subsequent inspection of the genes located within these QTLs revealed genes associated with the biosynthesis of secondary metabolites such as Phenylalanine Ammonia Lyase (PAL), a key enzyme in the synthesis of phenolic compounds, and two genes coding for R2R3-type MYB transcription factors. The identification of these two QTLs associated to allelopathy in rice provides a useful tool for further exploration and targeted breeding strategies.

Cadmium stress responses under white or blue light are influenced by putrescine pre-treatment in wheat

Blue light plays an important role in most plant functions: it influences plant morphology, photosynthesis, primary and secondary metabolism. Although certain studies have already revealed that blue light may have positive effects under certain stress conditions, its exact mechanism is largely unknown. The importance of polyamines in stress tolerance has been widely investigated; however, their interaction with the dependent processes is still poorly understood. In addition, the quality of light can also affect the polyamine metabolism, thus it can influence their roles and relationships with other protective compounds. According to these, the main question of the present work was that whether blue light induces different responses during Cd stress, especially which are related to polyamine metabolism, and whether it may be able to modify the protective effect of exogenous putrescine compared to white light conditions in wheat. It has been demonstrated that less pronounced Cd stress was detected under blue light than at white light conditions. Blue light had its own effect at metabolite and gene expression levels and the lower Cd uptake was accompanied by lower phytochelatin but higher conjugated polyamine accumulation at the same time. Putrescine pre-treatment had protective effect especially under white light conditions, and it highlighted certain differences observed under Cd stress between blue light and white light conditions, especially in phytochelatin synthesis, polyamine metabolism, and accumulation of phenolic compounds and plant hormones. Our data demonstrated that blue light regulated Cd tolerance in wheat and modified defence strategy when excess putrescine was present.

Upcycling Romaine lettuce outer leaves by infrared blanching and hot air drying.

Romaine lettuce outer leaves, as opposed to the more commonly marketed heart, are typically discarded and present an opportunity for upcycling as dried powders. Duquesne Romaine lettuce was evaluated to quantify and compare quality attributes of fresh outer and heart leaves, dried powders following hot air drying, and dried powders following an infrared (IR) blanching pretreatment before drying. Attributes measured for fresh leaves included moisture, water activity (Aw), color, total soluble phenolics (TSP), and antioxidant capacity (AC). Drying kinetics and time/energy saving through IR blanching were evaluated. Attributes measured for dried powders included moisture, Aw, color, true density, water vapor isotherms, TSP, AC, cadmium (Cd) content, and pesticide residues. TSP, AC, Cd, and pesticide residues were higher, whereas moisture content and Aw were lower in fresh outer versus heart leaves. Hot air drying reduced TSP and AC to 63.6% and 35.2% of fresh values, respectively, whereas IR blanching further reduced TSP and AC to 37.3% and 25.4% in outer leave powders. On the other hand, TSP and AC increased 237% and 151%, respectively, for unblanched heart powders. Higher increase of TSP than AC in heart leaf powder may indicate synthesis of phenolic compounds activated by abiotic stresses such as cutting and high temperatures at the initial drying stage. IR blanching resulted in significant time/energy savings for drying of outer leaves. Microbial loads were substantially reduced during drying, although microbial population on outer leaves were more resistant. Safe to eat outer leaf Romaine lettuce powders can be produced, assuming appropriate agricultural practices.