Search Results (105)

Crocus sativus L. (saffron), commonly known as “red gold,” is among the most valuable spices worldwide and has gained increasing attention as a high-value crop for small-scale farming systems. However, its production potential in the southern United States remains largely unexplored. This study evaluated saffron as an alternative specialty crop in Georgia by assessing the effects of planting date (early September vs. late October) and production system (open field vs. low plastic tunnel) on saffron yield during the 2023 and 2024 growing seasons at the Rodale Institute Southeast Organic Center. Simple postharvest stigma drying methods, including oven and microwave drying, were also evaluated descriptively for small-scale production. In 2023, a total of 1907 flowers were harvested, yielding 59.61 g of fresh stigma, whereas production declined in 2024 to 961 flowers and 22.89 g of fresh stigma. Year had a significant effect on yield, while planting date and production system did not show consistent main effects. A significant interaction between year and planting date indicated that saffron performance was influenced by year-specific growing conditions and management-related constraints, with early planting improving plant establishment. Stigma yield was limited for quality analysis; therefore, samples were composited, preventing valid inferential statistical comparisons for drying-method effects. Descriptively, concentrations of key apocarotenoids—crocin, picrocrocin, and safranal—were generally higher in 2024, with crocin values reaching up to 62.34. Higher-temperature drying (e.g., 100 °C) offered practical advantages due to substantially reduced drying time compared with lower-temperature (60 °C) or microwave drying; however, further replicated quality analysis is needed before firm conclusions can be drawn regarding drying-method effects. Overall, saffron production was feasible under humid subtropical conditions, but yield stability depended on stand establishment, soil fertility management, and year-specific growing conditions. These findings highlight the importance of integrated management of planting time, corm quality, production system, soil fertility, and postharvest processing for optimizing saffron production in emerging regions; however, larger-scale and long-term studies are needed to draw definitive conclusions. Full article

This study evaluated the effects of dietary S-abscisic acid (S-ABA) supplementation on reproductive performance and piglet growth in multiparous sows under commercial farming conditions. A total of 65 Landrace × Yorkshire multiparous sows were allocated to one of three dietary treatments: a basal diet (control); a basal diet supplemented with 1 ppm S-ABA; or a basal diet supplemented with 10 ppm S-ABA. The experimental period was set from weaning through the subsequent weaning (approximately 147 days), encompassing the non-pregnant, gestation, and lactation phases. Reproductive performance parameters, including the number of piglets born, the number of piglets weaned, and piglet body weight at birth and at weaning, were recorded, in addition to general health observations of sows and piglets. 1 ppm S-ABA supplementation significantly increased the number of piglets born compared to control (p < 0.05). Both 1 ppm and 10 ppm S-ABA supplementation resulted in a significantly higher number of piglets weaned (p < 0.05) and average piglet weaning weight (p < 0.01) compared with control, with no apparent differences in measured piglet survival outcomes among treatment groups. No additional benefits were observed when the supplementation level was increased from 1 ppm to 10 ppm. These findings suggest that dietary S-ABA supplementation at low inclusion levels may positively influence sow reproductive performance and piglet growth under practical feeding conditions. Full article

Carotenoids are an important class of natural compounds, essential for human nutrition, acting in plants as pigments and apocarotenoid precursors. Tomato is a key model for carotenoid metabolism, as genetic variation strongly affects carotenoid composition during fruit ripening. To date, most of the enzymes involved in the carotenoid pathway were mainly characterized by linking gain- or loss-of-function phenotypes to their genetic basis (e.g., mutation in a single gene), with limited integration into pathway-wide analyses. Here we report an extensive biochemical and molecular characterization of a collection of tomato carotenoid mutants—apricot (at), yellow flesh (r), tangerine (t), Delta (Del) and Beta (B)—throughout three different stages of fruit ripening (mature green, breaker, red ripe). Using correlation-based integrative analyses, we integrated targeted isoprenoid metabolomics (carotenoids, chlorophylls, tocochromanols, quinones, abscisic acid) with gene expression profiling and correlation-based analyses. The pronounced, stage-dependent remodeling of the isoprenoid profiles exceeded the expected changes in substrates/products and was accompanied by significant transcriptional changes, largely independent of the position of the mutated step in the pathway. This integration highlighted metabolite/transcript regulatory links and the central role of lycopene cyclization in isoprenoid metabolism rewiring, thus improving our understanding of mechanisms controlling their accumulation during tomato fruit ripening. Full article

β-Carotene has extensive applications in the food, pharmaceutical, and cosmetics industries. Traditional chemical synthesis methods face challenges such as byproduct residues and high costs, whereas natural extraction is constrained by low yields and complex processes. Recent advancements in synthetic biology and metabolic engineering have paved the way for the heterologous biosynthesis of β-carotene in microorganisms. Owing to its rapid growth, convenience of genetic manipulation, and suitability for producing apocarotenoids, Escherichia coli is an ideal host for the production of β-carotene and its derivatives, as exemplified by the record production of multiple apocarotenoids in engineered E. coli strains. Here, we summarize the metabolic engineering strategies employed to produce β-carotene in E. coli, including manipulation of the endogenous MEP pathway, introduction of the hybrid MVA pathway, modulation of central carbon metabolism, modification of the cell membrane, and fermentation process optimization. As β-carotene acts as a biosynthetic hub for many carotenoids and apocarotenoids, we also highlighted the importance of efficient β-carotene production for the sustainable preparation of these compounds. This review aims to provide theoretical insights for designing talented β-carotene producers and laying the foundation for the sustainable manufacturing of valuable carotenoids and apocarotenoids. Full article

Terpenoids constitute the largest class of plant-specialized metabolites, playing essential roles throughout the plants’ life cycle and having diverse applications for humans in nutrition, medicine, and flavor. 3-Hydroxy-3-methylglutaryl-CoA reductase (HMGR) is a rate-limiting enzyme of the mevalonate (MVA) pathway, producing sesquiterpenes, saponins, and other terpenoids. HMGR is post-translationally regulated by downstream MVA products through its N-terminal regulatory domain, limiting terpenoid production. To overcome this bottleneck, we employed a virus-based CRISPR/Cas9 system to genetically modify the N-terminal regulatory domain of HMGR in petunia (Petunia × hybrida) and lettuce (Lactuca sativa L.). In petunia, HMGR1-edited lines exhibited vigorous growth, larger flowers, and increased production of sesquiterpenes. Interestingly, they also showed enhanced production of phenylpropanoid volatiles, revealing a connection between these pathways. Transcript analysis revealed altered expression of genes involved in terpenoid biosynthesis, pyruvate metabolism, phenylpropanoid biosynthesis, and gibberellin- and auxin-related pathways, indicating enhanced carbon flux through these metabolic networks. In lettuce, HMGR7-edited plants displayed elevated emission of sesquiterpenes, apocarotenoids, and the phenylpropanoid benzaldehyde. Together, these results establish a transgene-free strategy to enhance the production of terpenoid and phenylpropanoid volatiles, and provide a framework for developing resilient, nutrient-enriched crops. Full article

Carotenoids are a class of C40 isoprenoid-derived fat-soluble pigments that play vital roles in plant physiology and human health and serve as precursors for several biologically critical regulatory molecules. Carotenoid cleavage dioxygenases (CCDs) are key enzymes that catalyze the selective oxidative cleavage of carotenoids into apocarotenoids, thereby significantly influencing plant development and responses to abiotic stress. Although extensive research has been conducted on many model species, comprehensive studies on the StCCD gene family in potato remain limited. In this study, we conducted a genome-wide analysis to identify and characterize the CCD gene family in potato. Phylogenetic and structural analyses classified the 17 StCCD genes into six distinct subfamilies, which are distributed across five chromosomes of the genome. Analysis of cis-acting regulatory elements revealed that the promoters of most StCCD genes contain various elements associated with light responsiveness, stress signaling, and phytohormone regulation. Molecular docking analysis indicated that CCD proteins exhibit distinct substrate specificity in their binding to carotenoids and intermediate products. The expression profiling of StCCD genes uncovered pronounced specificity in their expression, which was evident across tissues, throughout tuber maturation, and following exposure to abiotic stresses and hormonal applications. This specificity strongly implicates these genes in the regulation of developmental processes and stress adaptation mechanisms. This study provides a comprehensive genomic and transcriptomic overview of the CCD gene family in potato, establishing a foundation for functional characterization of individual genes in the future. Full article

Carotenoid cleavage oxygenases (CCOs) constitute a pivotal enzyme family that catalyze the oxidative cleavage of carotenoids to produce apocarotenoids, which are important signaling molecules involved in plant development, stress adaptation, and immunity responses. Notably, several CCOs, particularly NCED members, contribute to pathogen resistance by mediating abscisic acid (ABA) biosynthesis and apocarotenoid-derived defense signaling. While this gene family has been characterized in diverse plant species, its composition and functions in radish (Raphanus sativus L.) remain poorly understood. This study presents the comprehensive, genome-wide identification of the CCO gene family in radish, revealing 19 putative RsCCO members. A combination of phylogenetic, gene structure, chromosomal localization, and synteny analyses revealed conserved evolutionary patterns and species-specific diversification of the RsCCO family within the Brassicaceae. Promoter analysis identified an abundance of cis-acting regulatory elements related to phytohormone signaling, light perception, and stress responses, suggesting complex transcriptional regulation. Crucially, transcriptomic profiling following infection with Fusarium oxysporum revealed that two genes, RsNCED6 and RsNCED9b, were significantly upregulated in a resistant radish inbred line (‘T5’) compared to a susceptible line (‘T24’), identifying them as key candidate genes involved in ABA-mediated defense responses. This work provides a foundational characterization of the radish CCO gene family, offering novel insights into its role in carotenoid metabolism and pathogen defense. Full article

Saffron (Crocus sativus L.) is one of the most valued spices worldwide, rich in bioactive apocarotenoids such as crocins, picrocrocin, and safranal, which display antioxidant, neuroprotective, and anticancer properties. Saffron’s chemical composition is critical for its therapeutic efficacy and a combination of components appears essential to reach the best protection and increase tissue resilience, so stigmas were subjected to hydroalcoholic extraction followed by purification via solid-phase extraction to enriched crocin and picrocrocin fractions. The extracts were included in liposomes to enhance their bioavailability and gastrointestinal absorption by oral administration while protecting them in the harsh gastric environment, increasing their permeation and sustaining their release in the gastrointestinal tract. Liposomes were prepared by the reverse-phase evaporation method using saturated or unsaturated lipids extracted from soy. Encapsulation efficiency was determined by HPLC monitoring of trans-4GG crocin, cis-4GG crocin, and picrocrocin. The results indicate that liposomes show greater encapsulation capacity for hydrophilic apocarotenoids such as crocins (≈90% for cis-4GG, ≈50% for trans-4GG crocin) with respect to picrocrocins (<20%). These findings support the application of liposomal carriers to improve the stability, shelf-life, and potential bioavailability of saffron’s bioactive properties for nutraceutical, pharmaceutical, and functional food applications. Full article

Crocins are high-value apocarotenoid pigments with broad applications in pharmaceuticals, foods, and personal-care products, and they exhibit diverse bioactivities, including antioxidant, antidepressant, and antidementia effects. In this study, we achieved the heterologous biosynthesis of crocins in Solanum lycopersicum L. by introducing the GjCCD4a, GjALDH2C3, GjUGT74F8 and GjUGT94E13 of Gardenia jasminoides J.Ellis to the binary expression vector via in-fusion technology and self-cleaving 2A peptides. Following Agrobacterium-mediated transformation, the engineered tomato plants predominantly produced main active ingredient crocin I, which accounted for 97–99% of the total crocins. The transgenic fruits displayed mixed red-and-golden colouration. These results highlight S. lycopersicum as a promising chassis for crocin I biosynthesis, helping to address supply constraints and enabling colour-trait breeding through synthetic biology. Full article

Bixin, an apocarotenoid from Bixa orellana seeds, is a valuable natural pigment with industrial and pharmacological applications. Traditional extraction methods rely on organic solvents, but eco-friendly alternatives like silk fibroin solution (SFS) are emerging. This study evaluated SFS for bixin extraction from annatto seeds, optimizing conditions using Box-Behnken Design (BBD). The optimal parameters 1.5% SFS, 60 °C, and 60 min yielded 10.87 mg/mL (liquid extract of annatto seeds, LEAS + SFS) and 150.72 mg/g (solid extract of annatto seeds, SEAS + SFS). Cell viability was assessed in human dermal fibroblasts (HDFn) and RAW 264.7 murine macrophages via MTT assay. After 24 and 72 h, LEAS + SFS, SEAS + SFS, purified bixin (PB), and SFS maintained >70% viability in HDFn cells. Similarly, RAW 264.7 cells showed >70% viability after 24 h, indicating low cytotoxicity. These results highlight the biocompatibility of SFS-extracted bixin, supporting its potential in food, cosmetics, and biomedicine. The study demonstrates that SFS is an effective, sustainable alternative to traditional solvents, offering high extraction efficiency and minimal toxicity. This method aligns with green chemistry principles, providing a promising solution for bixin production. Full article

Crocin biosynthesis involves a complex network of enzymes with biosynthetic and modifier enzymes, and the manipulation of these pathways holds promise for improving human health through the broad exploitation of these bioactive metabolites. Crocins play a significant role in human nutrition and health, as they exhibit antioxidant and anti-inflammatory activity. Plants that naturally accumulate high levels of crocins are scarce, and the production of crocins is highly limited by the characteristics of the crops and their yield. The CCD2 enzyme, initially identified in saffron, is responsible for converting zeaxanthin into crocetin, which is further modified to crocins by aldehyde dehydrogenases and glucosyltransferase enzymes. Crops like tomato fruits, which naturally contain high levels of carotenoids, offer valuable genetic resources for expanding synthetic biology tools. In an effort to explore CCD2 enzymes with improved activity, two CCD2 alleles from saffron and Crocosmia were introduced into tomato, together with a UGT gene. Furthermore, in order to increase the zeaxanthin pool in the fruit, an RNA interference construct was introduced to limit the conversion of zeaxanthin to violaxanthin. The expression of saffron CCD2, CsCCDD2L, led to the creation of transgenic tomatoes with significantly high crocins levels, reaching concentrations of 4.7 mg/g dry weight. The Crocosmia allele, CroCCD2, also resulted in high crocins levels, reaching a concentration of 2.1 mg/g dry weight. These findings underscore the importance of enzyme variants in synthetic biology, as they enable the development of crops rich in beneficial apocarotenoids. Full article

Polyembryonic maize, capable of producing multiple seedlings from a single kernel, holds great potential value in agricultural and industrial applications, but the seedling quality needs to be improved. In this study, seedlings of two waxy maize (Zea mays L. sinensis Kulesh) inbred lines, D35 (a polyembryonic line with twin shoots) and N6110 (single-shoot), exhibited similar relative growth rates during 1 to 5 days post-germination. UPLC-MS/MS profiling of 3- to 5-day-old seedling roots and shoots revealed that H2JA, MeSAG, and IAA-Val-Me were the common differentially accumulated metabolites (DAMs) of the 3-day-old vs. 5-day-old seedlings of D35 and N6110 in the same tissues, and MeSAG, tZ9G, cZROG, and DHZROG were identified in D35 vs. N6110 across the same tissues and the same periods. RNA-seq analyses showed various processes involved in seedling development, including DNA replication initiation, rhythmic processes, the cell cycle, secondary metabolic processes, and hormone biosynthetic regulation. The differentially expressed genes (DEGs) between D35 and N6110 were significantly enriched in organic hydroxy compound biosynthetic, alcohol biosynthetic, organic hydroxy compound metabolic, abscisic acid biosynthetic, and apocarotenoid biosynthetic processes. The KEGG-enriched pathways of DAMs and DEGs identified that AUX1, AHP, A-ARR, JAR1, SIMKK, ERF1, and GID2 might be conserved genes regulating seedling growth. The integrated analyses revealed that 98 TFs were potentially associated with multiple hormones, and 24 of them were identified to be core genes, including 11 AP2/ERFs, 4 Dofs, 2 bZIPs, 2 MADS-box genes, 2 MYBs, 1 GATA, 1 LOB, and 1 RWP-RK member. This study promotes a valuable understanding of the complex hormone interactions governing twin-shoot seedling growth and offers potential targets for improving crop establishment via seedling quality. Full article

The aromatic C₁₃ apocarotenoid β-ionone is a high-value natural-flavor and -fragrance compound derived from the oxidative cleavage of carotenoids. Carotenoid cleavage dioxygenases (CCDs) play a pivotal role in the biosynthesis of volatile apocarotenoids, particularly β-ionone. In this study, we report the identification, cloning, and functional characterization of two CCD1 homologs: OeCCD1 from Olea europaea and InCCD1 from Ipomoea nil. These two species, which, respectively, represent a woody perennial and a herbaceous annual, were selected to explore the potential functional divergence of CCD1 enzymes across different plant growth forms. These CCD1 genes were synthesized using codon optimization for Escherichia coli expression, followed by heterologous expression and purification using a GST-fusion system. In vitro assays confirmed that both enzymes cleave β-carotene at the 9,10 (9′,10′) double bond to yield β-ionone, but only OeCCD1 exhibits detectable activity on zeaxanthin; InCCD1 shows no in vitro cleavage of zeaxanthin. Kinetic characterization using β-apo-8′-carotenal as substrate revealed, for OeCCD1, a K_m of 0.82 mM, V_max of 2.30 U/mg (k_cat = 3.35 s⁻¹), and k_cat/K_m of 4.09 mM⁻¹·s⁻¹, whereas InCCD1 displayed K_m = 0.69 mM, V_max = 1.22 U/mg (k_cat = 1.82 s⁻¹), and k_cat/K_m = 2.64 mM⁻¹·s⁻¹. The optimization of expression parameters, as well as the systematic evaluation of temperature, pH, solvent, and metal ion effects, provided further insights into the stability and functional diversity within the plant CCD1 family. Overall, these findings offer promising enzymatic tools for the sustainable production of β-ionone and related apocarotenoids in engineered microbial cell factories. Full article

Apocarotenoids are ancient signaling molecules that have played crucial roles in biological communication and adaptation across evolutionary history. Originating in cyanobacteria, these molecules have diversified significantly in plants, where they contribute to stress perception, developmental regulation, and environmental responses. While some apocarotenoids, such as abscisic acid (ABA) and strigolactones (SLs), have been formally classified as plant hormones due to the identification of specific receptors, many others remain functionally enigmatic despite their profound effects on gene regulation and plant physiology. In this study, we focus on β-carotene-derived apocarotenoids that lack identified receptors, shedding light on their potential signaling roles beyond traditional hormone pathways. By synthesizing current knowledge, we highlight key gaps in understanding their biosynthesis, transport, perception, and downstream effects. Addressing these gaps is essential for unraveling the full scope of apocarotenoid-mediated signaling networks in plants. A deeper understanding of these molecules could not only redefine plant hormone classification but also open new avenues for improving crop resilience and stress adaptation in the face of climate change. Full article

The petals of flowering plants should retain unique antioxidants that have not been found in the fruits, as the petals need to stay open to attract pollinators against photooxidation and devise a solution to avoid eating attacks. We reported that the yellow petals of freesia cultivars (Freesia x hybrida) accumulated original apocarotenoids, mono- and di-neapolitanosyl crocetin. Here, in the yellow petals, we discovered eight novel flavonoids by their structural determination, including four 3′-caffeoylquercetin 3,7-glycosides, one 3′-caffeoylquercetin 3-glycoside, and three 4′-caffeoylkaempferol 3,7-glycosides. The 3-carbon sugar part was a minor hexose dimer [D-glucosyl-D-glucoside or D-glucosyl-L-rhamnoside] with the β1,2-linkage, while the 7-carbon was usually O-glycosylated with D-glucose, L-rhamnose, or D-glucuronic acid. Such caffeoyl-flavonol glycosides were also present in freesia white petals, regardless of the cultivars and wild species. When dihydroflavonols, the last common precursors between flavonols and anthocyanins, switch to the flavonol route, these caffeoyl-flavonol glycosides are likely to be synthesized via quercetin or kaempferol. All the eight flavonoids exerted in vitro antioxidant activities against both lipid peroxidation and radical generation. Specifically, 3′-caffeoylquercetin 3-sophoroside and its 7-glucuronide showed superior antioxidant activity. Freesia yellow and white flowers have been utilized as edible flowers, indicating the importance of evaluating the human benefits and risks of newly identified flavonoids. Full article