Plants

Tacca chantrieri, black bat flower, has showy flowers often appearing almost black. Here, we present the genome sequence and corresponding annotation to identify the genetic basis of the pigmentation. Candidate genes associated with the anthocyanin biosynthesis were identified based on this genome sequence and investigated with respect to their properties. The best dihydroflavonol 4-reductase (DFR) candidate, which harbours all amino acid residues believed to be required for DFR activity, shows a threonine in the substrate preference determining position where most characterized DFRs display asparagine or aspartate. This amino acid residue appears to be frequent in the Dioscoreaceae family as a comprehensive investigation revealed.

Flow cytometry provides a reliable and fast method for estimating genome size and ploidy levels in plants. Until recently, most studies employed fresh tissues, which limits the use of the method with samples from remote areas or when an extremely high number of samples needs to be processed in a short time. Although there is growing evidence that silica-dried material can be used for ploidy estimation in some taxa, no flora-wide study has been available so far. Here, we provide methodological aspects of an unprecedented study exploring ploidy variation of non-apomictic angiosperms in the Eastern Alps. We have analysed ca. 45,000 silica-dried samples of 1135 species using flow cytometry with DAPI as stain. We were able to obtain ploidy level information from 1104 (97%) of species. The unsuccessful species included succulent plants of the family Crassulaceae (genera Jovibarba, Rhodiola, Sedum, Sempervivum), the achlorophyllous parasitic or mycoheterotrophic genera Orobanche and Hypopitis, and a handful of others. About 80% of samples were successfully analysed using a single universal protocol and leaf tissue, while in the remaining species the use of alternative tissues (such as petioles or flowers) and/or protocol modifications were needed (targeting composition of buffers, duration of fixation or staining time or use of alternative buffers). A total of 377 species (34%) included polyploid cytotypes and 179 (16%) species were ploidy-variable. As a community resource, we provide relative genome sizes and ploidy assignments of 1332 cytotypes retrieved from 1104 species along with methodological details (e.g. buffers, standards, analysed plant organs, histogram quality). We believe that this dataset will facilitate future research in particular species as well as in flora-wide investigations of ploidy level variation of the Central European flora in general. We are confident that novel cytotypes of many species will be discovered in other geographic areas, and we would be delighted if the present dataset could serve the botanical community for comparison.

Peanut (Arachis hypogaea L.), a vital oilseed and food legume, is cultivated across the globe. Genetic improvement via conventional breeding faces limitations from narrow diversity and reproductive barriers, underscoring the need for tissue culture-based regeneration and transformation platforms. This study optimizes an efficient, reproducible in vitro regeneration protocol using cotyledonary node explants from three Indian elite cultivars: GG-20, GJG-9, and TAG-37A. Explants from aseptically germinated seedlings were cultured on Murashige and Skoog (MS) medium with varying cytokinins (e.g., BAP 0-4 mg/L) and auxins (e.g., NAA 0.1-0.9mg/L), yielding direct multiple shoot induction without callus, minimizing somaclonal variation. Optimal shoot proliferation occurred on full-strength MS + 2 mg/L BAP for GG-20/GJG-9 (88.9% efficiency) and 4 mg/L BAP for TAG-37A ([~]89-100% efficiency); rooting peaked on half-MS + NAA (up to 88.9% in GG-20). Regenerated plants acclimatized successfully in greenhouse conditions. Additionally, a robust in planta Agrobacterium tumefaciens (EHA105, pGFPGUSPlus) transformation via plumular meristem pricking in GG-20 achieved 7.69% efficiency. Transgene integration was confirmed by GUS assay and PCR (GUS/hptII), with [~]64% soil establishment.

C4 photosynthesis is a CO2-concentration mechanism that separates CO2 fixation between two cell types, thereby reducing photorespiration and making C4 plants more efficient than their C3 counterparts. While the C4 cycle has evolved multiple times across different genera, this study evaluates very closely related C3 and C4 species within the genus Flaveria. Apart from their carbon metabolism, C4 plants also possess adaptations in their mineral nutrition. One key nutrient which is also directly involved in photosynthesis is phosphorus. It is absorbed by the plant in the form of inorganic phosphate and is an essential component of DNA, ATP, lipids, and carbohydrates. In the Flaveria C4 species, but not in the C3 species, phosphate limitation was shown to affect the dark reactions of photosynthesis. This study investigates how phosphate deficiency impacts the light reactions in C3 and C4 Flaveria plants. We observed a differential response in the functionality of photosynthetic energy conversion between the two species. When exposed to a limited phosphate supply, the C3 species reduced its linear electron transport rate while dissipating excess energy through high-energy quenching, which was regulated by a higher pH gradient across the thylakoid membrane. In contrast, the C4 species did not regulate its photosynthetic light reaction under phosphate limitation. Instead, it exhibited increased stress levels, evidenced by a stronger biomass reduction and the induction of stress markers in the leaves. Additionally, this study uncovered an acceleration in NPQ relaxation during phosphate limitation, regardless of the photosynthesis type. HighlightPhosphate deficiency reduced linear electron transport rates and induced dissipation of excess energy through non-photochemical quenching in the C3 Flaveria species, while in the C4 species, despite elevated stress levels, the photosynthetic light reactions were unaffected.

Betalamic acid is the chromophore of betalains, which are pigments of chemotaxonomic and physiological importance. This study involves RACE-PCR-based gene cloning, heterologous expression, protein purification, and steady-state kinetics of B. alba L. var. Rubra L-DOPA/dopamine-4,5-dioxygenase 1 (BrDOD1). BrDOD1 is a unique high betalamic acid-forming LigB homolog in plants having comparable affinity for both L-DOPA and dopamine (KM < 50 M). Ascorbic acid (10 mM) shifted the steady-state kinetics from inhibitory to activator at a particular substrate concentration of both L-DOPA and dopamine. This increased both KM and Vmax by more than 6.5-fold, indicating that ascorbic acid acted as a molecular crowding agent in the enzyme assay. BrDOD1s physiological substrate is L-DOPA as the reaction rate for L-DOPA was 6.6-fold higher than dopamine, L-DOPA was present in higher concentration than that of dopamine in the same plant, and molecular dynamic simulations showed better stability of BrDOD1-L-DOPA complex than that of dopamine. Further, two more LigB homologs from the same plant have also been cloned. Based on the betalamic acid-forming activity, molecular phylogeny, conserved structural regions, and theoretical pI, betalainic plant LigB homologs have been classified into three groups to better understand the evolutionary trajectory of the LigB homologs in plants.

Cadmium is a very toxic heavy metal. We studied Cd-treated barley plants with especial focus on rare atypical plants with signs of chlorosis. Cd treatment decreased the maximal photochemical activities of both photosystems while the activity of photosystem I decreased more than activity of photosystem II. In photosystem II, Cd treatment inhibited non-photochemical quenching that increased portion of unquenched "closed" complexes of photosystem II. The latter effect increased balance of limitations between the acceptor side of photosystem II (qC) and the donor side of photosystem I (Y(ND)) and raised the ratio qC/Y(ND). All these effects were enhanced in the atypical more damaged plants. Cd treatment reduced K content in the first leaves; in atypical plants, K content decreased even more. Cd treatment changed a pattern of stomatal conductance possibly by means of reducing K content in leaves. The untreated barley plants kept different stomatal conductance at adaxial and abaxial sides of leaves and fulfilled a complicated diurnal dynamics with large ups and downs of stomatal conductance. The typical Cd-treated plants were less flexible and demonstrated medium values. Stomatal conductance in the untreated plants were higher or lower than in the typical Cd-treated plants depending on a particular time; average daytime stomatal conductance was equal in both variants. At 10.00, stomatal conductance in the atypical Cd-treated plants was smaller than in the typical ones. Levels of 13 chloroplast mRNAs remained unchanged, while psbD decreased in both types of Cd-treated plants. HighlightsO_LISeveral Cd effects were enhanced in more damaged (atypical) chlorotic plants C_LIO_LICd treatment decreased activity of photosystem I and non-photochemical quenching C_LIO_LIRatio of limitations between photosystems II and I [qC/Y(ND)] was rather constant C_LIO_LICd treatment reduced K content in the first leaves C_LIO_LICd treatment changed pattern of stomatal conductance C_LI

Fusion of gametes possessing meiotically reduced (haploid) chromosome complements is the main pathway of propagation among eukaryotes. However, duckweeds, the smallest angiosperms, propagate mainly vegetatively, and meiosis has not yet been documented in detail for this plant family. The more surprising was the recent evidence of rather frequent interspecific hybrids and triploid clonal accessions which became obvious by genome size measurements, genomic in situ hybridization (GISH) and combined plastid and nuclear DNA markers. These observations indicated sexual propagation involving reduced as well as unreduced male and female gametes in Lemna minor and L. turionifera leading to allodiploid and allotriploid hybrids (MT, MMT, MTT) and autotriploid L. minor (MMM) accessions. Here, we i) documented the meiotic stages of Lemna species for the first time; ii) provided evidence of unreduced male gametes through fluorescent in situ hybridization (FISH) with single locus probes; iii) determined their abundance in different individuals and iv) hypothesized about the reasons of unreduced male gamete formation. These findings open new insights into the modes of sexual reproduction and evolution of duckweeds which may be useful for future breeding efforts in this emerging crop.

Virus induced gene silencing (VIGS) is a method that exploits plant antiviral defence mechanisms to downregulate endogenous genes. The technique is versatile, rapid, and widely used for functional genomics studies. Here we report a method for VIGS in the medicinal plant, Calendula officinalis (pot marigold). This species produces anti-inflammatory triterpenoids and has also been bred and cultivated as an ornamental plant. We describe a method for the injection of Agrobacterium tumefaciens cultures into leaf midribs and compare visual marker genes for tracking VIGS utilising constructs that simultaneously target visual marker and target genes. We use these tools to demonstrate that silencing a gene encoding cycloartenol synthase results in changes to leaf phytosterols. This method could be used to further investigate the genetic basis of specialised metabolism in this species and could be adapted to other members of the Asteraceae family, many of which are of economical and chemical value.

BackgroundPlants are exposed to various environmental challenges. With ongoing climate change, droughts and insect outbreaks are expected to become more frequent. Thus, a better understanding is needed of how different plant species respond to such single and combined challenges. This study investigated common versus species-specific responses to environmental challenges in three perennial plant species of different growth forms and whether responses differ intraspecifically among accessions. Clones of different accessions of the herbaceous species Tanacetum vulgare, the woody vine Solanum dulcamara, and the tree Populus nigra were subjected to similar control, herbivory, drought, and combined (drought and herbivory) treatments for the same periods. After the exposure, concentrations of foliar phytohormones and various morphological traits were measured. ResultsAcross all species, several foliar phytohormones and one of ten morphological traits responded consistently to the environmental challenges. Jasmonoyl-isoleucine was induced by herbivory and the combined treatment, abscisic acid (ABA) by drought and the combined treatment, and indole acetic acid by the combined treatment in all species. Root mass remained unchanged in all species. However, structural equation models (SEMs) revealed a shared regulatory pathway across species in which ABA connected treatment and root mass, indicating a common hormonal response potentially linking challenges to growth responses. Despite these common patterns, species-specific responses were pronounced. In P. nigra, a unique induction of salicylic acid was found under the combined treatment, while aboveground mass and root-shoot ratio remained unaffected by any treatment, in contrast to the other two species. Species-specific SEMs further indicated distinct phytohormone-mediated pathways underlying morphological variation. Phenotypic plasticity reflected these species-specific patterns, with none of the phytohormones or morphological traits exhibiting uniform plasticity across species. Intraspecific variation further shaped responses, as phytohormone and morphological trait plasticity depended on accession, indicating substantial accession-specific plant responses. ConclusionsOur results indicate that some responses to comparable challenges may be conserved across species, while others are species-specific. The combined treatment elicited the most pronounced responses, and such complex responses may become more frequent under current global change. Our study highlights that comprehensive understanding of plant responses requires systematic comparisons at both interspecific and intraspecific scales.

Spinach (Spinacia oleraceae) is a principal vegetable crop commercially grown in Controlled Environment Agriculture (CEA). Recent research suggests that root morphological and architectural differences among crop species influence yield, resource use efficiency, and environmental stress tolerance. These root traits may be exploited to increase yield, promote efficient nutrient use, and mitigate environmental stressors. This study measured differences between various spinach cultivars in CEA systems to reveal morphological and anatomical variation. We grew three spinach cultivars with different reported growing rates ( Income, Darkside, and El-Majestic) under NFT hydroponic and substrate-based systems in a controlled greenhouse environment over 45 days with destructive harvests at days 15, 30, and 45. Supplemental light (250 {micro}mol/m2/s) with 12-hour photoperiod and periodic fertigation was used. Harvests included the collection of leaf and root biomass, and scanning of root systems in WinRhizo software, measuring ten variables. On day 45, root cross-sections from orders 1-5 were embedded in JB-4 resin, sectioned, stained, and analyzed for diameter, vasculature, and rhizodermis characteristics. Results indicate that in spinach, differences in root system morphology are linked to cultivation systems over cultivar identity. Vascular and root anatomical alterations are minor compared to morphological differences in response to the cultivation system. Hydroponic-style growth systems are associated with the proliferation of fine-root ideotypes compared with substrate-based conditions. Such findings affirm previous studies, which suggest plastic root morphology in response to growth systems, and may be used to help create more resilient, resource-efficient cultivars. HighlightsO_LIIn spinach, root system morphology differences are linked to cultivation systems. C_LIO_LIRoot vascular and anatomical alterations are minor in response to cultivation system. C_LIO_LIHydroponic growth systems are linked to fine-root ideotype proliferation in spinach. C_LIO_LIFine-root ideotype proliferation may be a breeding target for CEA spinach. C_LI

The nucleus is the characteristic organelle for eukaryotic organisms. Unlike the classic textbook view of static two-dimensional nuclei, nuclear shape is dynamic inside the live cell. The alteration or deformed nuclear shape is the hallmark of cancer in animal cells and environmental stress in plants. The nuclear envelope proteins interact with chromatin to regulate gene expression. Unfortunately, we have limited knowledge about the impact of abiotic stress on nuclear shape, movement, and chromatin dynamics. To circumvent this issue, we are utilizing a dual fluorescently tagged marker lines - nuclear envelope protein and chromatin - to perform live cell imaging in the model plant Arabidopsis thaliana root. The live cell imaging was performed in control and salt-stressed conditions. We utilized these captured movies to analyze through open-source image processing software Fiji/ImageJ with the help of the TrackMate plugin. Using this method, we have demonstrated that chromatin velocity is decreased in salt-treated conditions. This method will be widely applied to quantitative live cell imaging of nuclear shape and chromatin dynamics during plant development and environmental stress. SummaryThis process aims to simultaneously record nucleus and chromatin dynamics in Arabidopsis thaliana roots and investigate changes in these dynamics in response to developmental and environmental cues.

Plant genome sequences provide access to the gene repertoire of a species. This facilitates basic research, biotechnological processes, or horticultural applications. Here, we present the genome sequence of Begonia manicata and unravel the genes underlying the pigmentation of red structures emerging from its leaves and stems. Structural genes of the anthocyanin biosynthesis and corresponding regulatory genes were discovered to be upregulated in these red structures suggesting that the pigmentation is caused by the accumulation of anthocyanins. Our work provides a resource for future studies on pigmentation of Begoniaceae.

Urban green areas often harbour numerous non-native urban trees, many of which have characteristics that predispose them to escape from cultivation and become potentially invasive. Climate change is expected to exacerbate this risk by creating favourable conditions for species that are currently climatically restricted. The potential risks for invasiveness of urban tree species in continental Europe are not yet known. Here, we provide a comprehensive risk screening of 34 non-native urban tree species in continental Europe, for both current and projected future climate scenarios. Using the Terrestrial Plant Species Invasiveness Screening Kit (TPS-ISK v2.4), we assessed invasion risk based on biogeography, ecology, and projected responses to climate change. Results showed that under current conditions, 10 species (29.4%) were categorised as high risk, 23 (67.6%) as medium risk and one (2.9%) as low risk. The inclusion of climate change projections increased the number of high risk species to 11, with seven species categorised as very high risk. These taxa exhibit strong ecological plasticity, high reproductive performance and broad environmental tolerance, which together with projected warming, emphasises their significant potential for further spread. Our results emphasise the urgent need for early detection, continuous monitoring and proactive management of non-native urban trees in Europe, especially those that are widely used in horticulture and forestry. By integrating invasion biology with climate change risk screening, this study provides an important basis for evidence-based policy and management strategies to mitigate future ecological and economic impacts of invasions by urban trees.

BackgroundExtensin peroxidases (EPs) are class III plant peroxidases and are responsible for intermolecular covalent crosslinking of extensin (EXT) monomers to create scaffolds within plant cell walls. The formation of these scaffolds impacts plant development, mechanical wounding, and response to pathogen attacks. Therefore, elucidating the molecular mechanism controlling covalent crosslinking of EXT monomers is crucial for understanding cell wall deposition and potentially improving plant growth and adaptation. The focus of this work is to use in silico analysis to determine the structural characteristics of an EP from tomato (TomEP) to elucidate its specificity for crosslinking of EXT monomers. ResultsIn this study the two-dimensional (2D) and three-dimensional (3D) structures of TomEP were determined using several advanced bioinformatics tools and compared to two other peroxidases: GvEP1 (a known EP) and HRP-C (having a low affinity for EXT substrates). The results revealed that TomEP is a stable and hydrophilic protein with high thermal stability. The heme binding pockets of TomEP and GvEP1 have more hydrophobic residues and larger volume and pocket area compared to HRP-C. Molecular docking at the active site, which includes a heme heteroatom, showed that the ligands consisting of the hydrophobic Tyrosine-X-Tyrosine [-Y-X-Y-] motifs (i.e., [-Y-K-Y-], [-Y-V-Y-], and [-Y-Y-Y-] found in EXTs, and their derivatives, Isodityrosine (IDT), Pulcherosine (Pul), Di-Isodytirosine (diIDT), bind perfectly to the active site of TomEP with dominant interactions of Val54, Ser94, Ala96 and Phe196 residues. Pulcherosine had the highest binding affinity, while [-Y-K-Y-] showed the lowest binding affinity. Molecular dynamics simulations showed that [-Y-X-Y-] motifs (and the derivative substrate ligands) remain bound to the active site of TomEP throughout the 100 ns long simulation. Furthermore, the binding of these substrates stabilized the protein structure. ConclusionThese results may explain why TomEP is particularly well-suited for EXT crosslinking and will have significant implications on biochemistry, biotechnology, and the potential use of these EPs in crops improvement.

CoverCress is a new winter annual oilseed crop developed from field pennycress within the past 20 years. Field pennycress is commonly considered to be self-pollinated but little basic research has been published and there is some misalignment of conclusions. Our experience working with pennycress plant growth in greenhouse and field conditions over the past 13 years suggests that outcrossing is uncommon. We conducted lab, greenhouse, and field experiments to strengthen the body of work. Pollen viability kinetics analysis showed that longevity of pollen viability is negatively impacted by increasing temperatures and by direct exposure to light. Samples treated at 4C declined to 50% viability in 12 hours while it took just 2.5 hrs at 37C, and 1.6 hrs in full sunlight on a cool early April day. Cross-pollination was absent among greenhouse-grown plants flowering inside an agitated plastic pollen-containment covering. Across greenhouse tests, high rates of cross-pollination occurred only in an emasculation treatment that rendered flowers male sterile and opened the pistil to cross-fertilization. Field trials designed to measure pollen flow distance using a trackable fae1 knockout reporter gene failed to show detectable movement of pollen under field conditions in two locations. This data strongly suggests that domesticated field pennycress may be considered a self-pollinated crop and managed as such.

The aim of this study was to assess the efficiency of two intercrop species, Canavalia ensiformis and Desmodium intortum, to reduce weed growth, herbicide use and damage by the stalk borer Chilo sacchariphagus in sugarcane cropping system in Reunion. We compared six inter-row management techniques: four treatments combined the two intercrops Canavalia ensiformis or Desmodium intortum sown either early (between 0 and 2.1 months after sugarcane emergence) or late (between 1.3 and 3.7 months after sugarcane emergence), a treatment where no weeding was carried out on the inter-row, and a treatment with chemical weeding of the inter-row (CcWp). In all treatments, the sugarcane row was weeded chemically and manually. The six treatments were compared in a multilocal randomized block design with three localities, during one or two crop cycles depending on the locality. Desmodium intortum produced poor ground coverage in half of the trial x crop cycles and was therefore found unsuitable for use as an intercrop of sugarcane in our conditions. On the opposite, Canavalia ensiformis quickly covered the inter-rows, regardless of the sowing date. The Canavalia ensiformis intercrops allowed a reduction of herbicide consumption by 63% when sown early and by 28% when sown late, compared to the CcWp control treatment. Both Canavalia ensiformis intercrops caused a reduction of weed coverage on the inter-row similar or better than the chemical control. However, the early sown Canavalia ensiformis intercrop caused a 18.6 t.ha-1 yield loss compared the chemical control. No yield loss was detected with the late sown intercrop. A significant reduction of stalk damage by a 0.8-fold factor was observed in the early sown Canavalia ensiformis treatment.

Photosynthesis accounts for most of the final grain yield in rice, making improvements in radiation use efficiency (RUE) a key strategy for enhancing productivity. Agronomically, RUE is defined as the biomass produced per unit of total solar radiation or photosynthetically active radiation intercepted by the canopy. However, the interaction between carbon and nitrogen metabolism plays a critical role in determining plant growth and grain yield. Assimilated nitrogen is required for the synthesis of photosynthetic pigments and enzymes, while the reduction of nitrate (NOLL) and nitrite (NOLL), as well as the assimilation of ammonium (NHLL), depend on the reducing power and carbon skeletons generated by photosynthesis. In this study, two high-yielding rice (Oryza sativa) cultivars--an indica-type (El Paso 144) and a japonica-type (INIA Parao) were subjected to two nitrogen treatments (3 mM and 9 mM NOLL/NHLL) and two light intensities (850 and 1500 mol mL{superscript 2} sL{superscript 1}). A strong interaction between light intensity and nitrogen metabolism was observed, with contrasting responses between subspecies. These differences reflect a coordinated regulation of carbon assimilation and primary nitrogen metabolism. The results provide new insights into the metabolic strategies underlying nitrogen compound accumulation under variable irradiance. Such knowledge is essential for improving nitrogen fertilizer use efficiency and yield performance in elite rice genotypes cultivated under commercial field conditions.

Grape (Vitis vinifera L.) is one of the most cultivated plant species and has a long history in the Levant. Grape products, including leaves, are highly appreciated as healthy products, mainly because of their high levels of nutraceuticals. The significance of these products lies in the fact that poor diet is the primary cause of malnutrition, which is associated with severe noncommunicable diseases. Accordingly, this study aimed to profile secondary metabolites in a selection of grape genotypes from Hebron and Bethlehem regions in the West Bank-Palestine that include both indigenous and introduced genotypes. Fresh, delicate leaves from each genotype-region combination were analyzed for their content of secondary metabolites via LC-MS. The results revealed that the collection regions had a negligible impact, whereas the genotype impact was high and significant. More importantly, the secondary metabolites profiles of leaves allow for the clustering of the assessed genotypes into a few clusters, each with a specific set of metabolites that can serve as fingerprint profile. In conclusion, the results of the present study revealed the diversity of grape genotypes at the metabolomics level, which will help preserve indigenous grape genotypes and aid in the development of grape varieties that can cope with the adverse impacts of climate change.

Background and AimsL-DOPA is an important pharmaceutical that accumulates to high levels in the legume faba bean (Vicia faba). L-DOPA is likely derived from L-tyrosine but the responsible enzyme (L-tyrosine oxidase) remains unknown. Availability of L-tyrosine may be a key factor controlling L-DOPA accumulation. In legumes, L-tyrosine is supplied via either a plastidial TyrA enzyme (ADH) or a deregulated cytosolic homolog (PDH). This study aimed at identifying L-tyrosine oxidase and TyrA genes from faba bean. MethodsWe used gene-to-metabolite correlations and homology-based searches to select fifteen L-tyrosine oxidase candidates, which were tested in yeast and in the model plant Nicotiana benthamiana. We also used isotopically labeled L-tyrosine to measure biosynthetic activity in different faba bean tissues and to test an alternative biosynthetic hypothesis. Three faba bean TyrA genes were inferred by homology and assayed in N. benthamiana by co-expression with a known L-tyrosine oxidase, CYP76AD6. Key ResultsNone of the L-tyrosine oxidase candidates produced L-DOPA upon heterologous expression. Feeding experiments showed a lack of correlation between L-DOPA accumulation and biosynthetic capacity. Feeding studies also disproved an alternative route to L-DOPA by oxidation of 4-hydroxyphenylpyruvate. Of the TyrA genes, two were able to increase L-tyrosine levels in N. benthamiana 2-3-fold (VfADH and VfPDH), and one of them was able to boost the levels of L-DOPA derivatives up to 6-fold (VfADH). ConclusionsThe faba bean L-tyrosine oxidase remains unidentified, with a possible transport of L-DOPA across tissues likely having confounded our correlation-based selection strategies. In N. benthamiana, both VfADH and VfPDH can increase the levels of L-tyrosine, while VfADH can further boost the levels of L-DOPA derivatives. Our work delivers a strategy to boost the provision of L-tyrosine in N. benthamiana and provides valuable insights in the search for the elusive L-tyrosine oxidase from faba bean.

CONTEXTRapeseed is a globally significant oil crop, exhibiting highly plastic responses among seed yield components (seed number and weight). However, there remains a notable gap in knowing the distribution of quality traits among seed size categories and understanding how seed size and source-sink (S-S) ratio influence comprehensive seed quality traits. OBJECTIVEThis study investigated the effects of seed size and S-S ratio reduction on the quality traits of winter and spring rapeseed genotypes. METHODSThe experiments were carried out at field conditions in Valdivia, Chile, where seed yield, yield components, oil, protein, and element concentrations (P, K, S, Ca, Mg, B, Cu, Fe, Mn, Zn, and Na) were evaluated across five seed size categories; very small (< 1.4 mm), small (1.4-1.7 mm), medium (1.7-2.0 mm), large (2.0-2.36 mm), and very large (> 2.36 mm). Treatments included a control and a reduced S-S ratio (75% shading), which significantly increased seed weight (P < 0.05). RESULTSBoth genotype and seed size affected (P< 0.050) the quality traits. Larger seeds exhibited higher Mg and B concentrations, as well as lower K, Ca, Fe and Na. Shading affected seed size distribution, favouring a higher proportion of large seeds. Under the shading treatment, the small seed category reached 5% lower oil concentration, while protein seed concentration increases 6% in both genotypes. Principal component analysis highlighted the complex interaction between yield, yield components, and quality traits, since there was no clear separation between different seed size categories and S-S ratio treatments. CONCLUSIONThese results provide insights into the plasticity of rapeseed quality traits, highlighting their collective impact on nutrient profiles. SIGNIFICANCEThis information is helpful for optimising cultivation practices and informing breeding programmes aimed at improving seed quality, particularly in high-yielding environments susceptible to environmental stresses. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=90 SRC="FIGDIR/small/707178v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@19d16eforg.highwire.dtl.DTLVardef@4cc16forg.highwire.dtl.DTLVardef@12f741borg.highwire.dtl.DTLVardef@6fa37a_HPS_FORMAT_FIGEXP M_FIG C_FIG