Search Results (674)

Organic systems rely on nitrogen (N) supplied through organic sources that must be mineralized before uptake. The timing and rate of N release are often difficult to synchronize with crop demand, especially for short-duration crops like bok choy. We evaluated the response of bok choy to N rates in Florida sandy soils using five N rates (0, 56, 112, 168, and 224 kg N ha⁻¹) in a randomized complete block design. Yield, N uptake, apparent N recovery, N balances, and in-season crop indicators (SPAD, sap nitrate) were measured across three years. N applications significantly increased yield in 2023 and 2025 (with no significant differences in yield above 112 kg N ha⁻¹), but not in 2024, highlighting the variability in crop response, likely due to environmental conditions. Higher N rates increased plant N accumulation but reduced N recovery and increased N surpluses, indicating a greater potential for N losses. SPAD and sap nitrate measurements were positively related to yield and could be used as rapid indicators of in-season crop N status, with SPAD having the advantage of being non-destructive. Overall, these findings help to optimize N management to better match crop demand in organic leafy green production systems, improving productivity while minimizing environmental costs. Full article

Leaf senescence negatively impacts yield and postharvest quality in non-heading Chinese cabbage (Brassica rapa ssp. chinensis), and the STAY-GREEN (SGR) homologs BcSGR1 and BcSGR2 function as core regulators of chlorophyll degradation. In this study, we constructed CRISPR/Cas9 single- and dual-gene editing vectors using four high-efficiency, high-specificity single-guide RNAs (sgRNAs). By optimizing the transformation system using petiolate cotyledon explants supplemented with 6 mg·L⁻¹ AgNO₃, we obtained a PCR-positive transformation efficiency of 26% (this value reflects transformation efficiency; the actual gene editing efficiency for each mutant line is presented in the target sequencing results) and generated BcSGR1 (YB1) and BcSGR2 (YB2) single mutants and a BcSGR1/BcSGR2 double mutant (DKO). All mutant lines exhibited a pronounced stay-green phenotype and delayed leaf senescence. The DKO line produced 3.15-fold higher chlorophyll and only one-quarter of the wild-type MDA level, indicating an additive enhancement effect of the double knockout. Compared with the wild type (3-day shelf life), YB1, YB2 and DKO extended postharvest longevity to 7, 8 and 11 days, with senescence delayed by 15, 18 and 22 days, respectively. Notably, whereas the YB1 and YB2 displayed mild leaf shriveling at later developmental stages, the DKO maintained normal leaf morphology. Collectively, our findings demonstrate that dual editing of BcSGR1 and BcSGR2 exerts an additive effect on delaying leaf senescence and enhances postharvest shelf life without incurring significant yield penalties under the experimental conditions. This study provides a feasible and effective strategy for breeding stay-green cultivars of non-heading Chinese cabbage. Full article

With the intention of investigating in further depth the horticultural biodiversity resulting from the selection and conservation effort carried out by farmers (custodians) who are dedicated to growing traditional products, we focused on six local landraces of Brassica rapa L. subsp. sylvestris (L.) Janch.; we conducted analyses addressing the presence of glucosinolates (GLSs), phenolic compounds and the antioxidant capacity of extracts of B. rapa landraces belonging to three groups with different growth phase behavior from planting to inflorescence appearance in the Salento area (Puglia or Apulia region, Italy). The studies focused on three local landraces known by Salento farmers as cima di rapa cinquantina (two separate accessions, 50SC and 50SD), cima di rapa sessantina (accessions 60SC and 60SD) and rapacaula (accessions rcSD and rcGA). We revealed the presence of eleven different glucosinolates and three main flavonoids, such as kaempferol, quercetin and isorhamnetin derivatives. The distribution and content of glucosinolates and flavonoids varied widely among the different landraces. Glucobrassicanapin was the predominant compound in all landraces, followed by gluconapin, except for 60SC, where the main GLS was the indolic glucobrassicin. Moreover, 50SC, 50SD and 60SC are characterized by the highest flavonoid content and the highest antioxidant capacity. The findings provide the basis for the characterization of B. rapa subsp. sylvestris L. local landraces as a useful source of valuable metabolites for human health, as well as for identifying one landrace with higher nutritional value as a starting point for accession conservation and economic development. Full article

Saline–alkali stress severely restricts leafy vegetable growth by impairing photosynthesis, ion homeostasis, and oxidative balance. This study investigated whether exogenous melatonin could alleviate saline–alkali stress in pakchoi (Brassica rapa subsp. chinensis) through coordinated protection of photosynthetic electron transport, ionic balance, and antioxidant defense. Pakchoi plants were subjected to four treatments: normal nutrient solution (CK), 100 μM melatonin (MT), 100 mM mixed saline–alkali stress with NaCl:NaHCO₃ at 2:1 (SAS), and saline–alkali stress plus melatonin (SAS+MT). After 7 d, growth traits, gas exchange, chlorophyll fluorescence, OJIP transients, ion contents, osmotic adjustment, oxidative damage, and antioxidant enzyme activities were analyzed. Saline–alkali stress markedly inhibited growth, reduced photosynthetic pigment contents and gas exchange, impaired PSII photochemical performance, disrupted ion balance, and increased ROS accumulation and membrane damage. Compared with SAS, SAS+MT increased net photosynthetic rate (Pn) by 66.2%, effective quantum yield of PSII [Y_(II)] by 56.0%, electron transport rate (ETR) by 57.9%, and the performance index on absorption basis (PI_ABS) from 0.80 to 1.80. Melatonin also reduced Na⁺ content by 38.7%, increased the K⁺/Na⁺ ratio from 1.0 to 2.2, and enhanced superoxide dismutase (SOD),peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) activities by 20.5%, 24.4%, 29.2%, and 33.3%, respectively. These results indicate that melatonin alleviates saline–alkali injury in pakchoi by maintaining PSII electron transport, improving ion homeostasis, and strengthening antioxidant defense. Full article

Hyperuricemia (HUA) is a metabolic disorder caused by excessive uric acid (UA) production and/or insufficient UA excretion. Brassica rapa L. (turnip) is a traditional medicinal and edible plant in northwestern China. In this study, the urate-lowering effects of B. rapa L. ethanol extract (BrEE) and associated underlying mechanisms were investigated using a hypoxanthine/potassium oxonate-induced HUA mouse model and UA-stimulated HK-2 cells. BrEE was prepared and characterized; quercetin-3-glucuronide was the most abundant compound in BrEE, with a relative abundance of 22.04%. BrEE significantly lowered serum UA levels and improved renal function in mice. Key UA-producing enzymes, xanthine oxidase (XOD) and adenosine deaminase (ADA), were suppressed and renal UA transporters were modulated to enhance excretion: URAT1 and GLUT9 were downregulated and ABCG2 was upregulated. These results indicated that BrEE’s protective effects were associated with its regulatory effects on UA transport-related protein expression. BrEE also alleviated oxidative stress, and reduced inflammation and renal pathology. Meanwhile, molecular docking predicted favorable binding between the major BrEE constituents and XOD or URAT1, providing preliminary support for their potential interactions with these targets. Thus, BrEE exerted multi-target urate-lowering and kidney-protective effects, providing preliminary evidence for the potential of B. rapa L. as a plant-derived resource for further investigation in the development of functional food ingredients to regulate urate metabolism. Full article

Shade avoidance response (SAR) is an important adaptive mechanism that enables plants to optimize light capture in dense canopies, but excessive shade-induced hypocotyl elongation can negatively affect plant architecture, yield, and quality in Chinese cabbage. In this study, we investigated the genetic basis of SAR using an advanced intercross recombinant inbred line (AI RIL) population derived from a cross between the oil type Chinese cabbage ‘R500’ with significantly longer hypocotyls and the vegetable type Chinese cabbage ‘L58’ with shorter hypocotyls. Quantitative trait locus (QTL) mapping under simulated shade, represented by a low red/far-red light ratio of 0.5, and non-shade conditions, represented by a high red/far-red light ratio of 2.0, identified several candidate genes associated with hypocotyl elongation, including COP1, XTH17, HYH and SRR1. Among these genes, BrSRR1 was selected for functional validation by introducing two alleles of BrSRR1 coding sequences into the Arabidopsis srr1 mutant. Under simulated shade, the srr1 mutant exhibited significantly longer hypocotyl than wild-type Col-0, whereas the BrSRR1-L58 restored hypocotyl length to a level statistically indistinguishable from that of wild-type Col-0. In contrast, the BrSRR1-R500 failed to complement the mutant phenotype, indicating ecotype-specific and allele-dependent functional divergence. Collectively, these findings indicate that BrSRR1 is implicated as a candidate gene involved in negative regulation of shade-induced hypocotyl elongation, though pending validation in the native species, providing insights into the genetic regulation of SAR in Chinese cabbage and a potential target for breeding varieties with reduced shade-induced hypocotyl elongation suited to high-density planting. Full article

Glycoside hydrolase family 1 (GH1) β-glucosidases (BGLUs) play diverse roles in plant development and stress responses. However, a comprehensive pan-genomic characterization of this gene family across diverse Brassica rapa accessions is still lacking. Here, we conducted a pan-genome-wide analysis of BGLU genes across 21 B. rapa accessions. A total of 1840 BGLU genes were identified and clustered into 57 orthologous gene groups (OGGs), comprising 22 core, 19 dispensable, and 16 private groups. Phylogenetic reconstruction assigned these OGGs to five subgroups, and duplication analysis revealed whole-genome duplication as the predominant driver of family expansion, accounting for 47.51% of duplicated genes. Expression profiling identified two core genes, BrBGLU10 and BrBGLU56, as specifically expressed in fertile floral buds and differentially regulated between fertile and sterile lines. CRISPR/Cas9-mediated knockout of BrBGLU10 resulted in approximately 36% pollen abortion and drastically reduced seed set upon self-pollination, supporting its important role in pollen development. Collectively, these findings establish BrBGLU10 as an important regulator of pollen development and a potential target for fertility-related applications via gene editing in B. rapa and related Brassica crops. Full article

Water hyacinth has become a major environmental problem in aquatic ecosystems worldwide, including Indonesia, due to its rapid growth and extensive surface coverage. Transforming this invasive biomass into high-quality compost offers a sustainable solution for biomass management and agricultural utilization. However, information regarding the combined effects of decomposer selection and the compost aeration process on compost quality, nutrient transformation, and agronomic performance remains limited. This study was conducted in Rawa Pening, Central Java, Indonesia, to determine how decomposer type and turning regime (specifically the frequency and method of mechanically aerating the compost pile) influence the quality of water hyacinth compost and to identify the most suitable formulation for pak choi (Brassica rapa L.) growing media. The experiment consisted of four sequential stages: composting, compost quality assessment, compost selection, and plant growth bioassay. Three decomposers (EM4™, cow dung, and Stardec™) were evaluated under turning and no-turning conditions using a factorial completely randomized design. Compost quality was assessed based on physicochemical characteristics, nutrient composition, compost yield, and correlation analysis. The best compost treatment was subsequently evaluated in different soil–compost mixtures using ANOVA, PCA, and correlation analysis. The results demonstrated that turning and decomposer selection acted synergistically to determine compost performance. Cow dung consistently produced the highest compost yield, whereas Stardec™ combined with turning generated the most mature compost, characterized by the lowest C/N ratio and the highest nitrogen and phosphorus contents. Plant bioassay confirmed that the optimal growing medium consisted of 50% soil and 50% compost, which maximized vegetative growth by balancing nutrient availability with physical support for root development. No toxicity symptoms were observed, indicating that mature water hyacinth compost is safe for agricultural use. These findings provide practical guidance for selecting decomposers based on compost production objectives and promote the sustainable utilization of invasive water hyacinth. Full article

Leafy head formation is a critical agronomic trait that determines the yield and quality of Chinese cabbage (Brassica rapa), involving complex morphological transitions. While BEL1-like homeodomain (BLH) transcription factors regulate development, their specific roles in heading remain elusive. To systematically identify the BraBLH gene family and elucidate its expression networks and regulatory functions during leafy head formation, a total of 36 BraBLH genes were identified. The phylogenetic analysis revealed that Brassica rapa had a specific clade (Group II). A high-resolution spatiotemporal expression framework for the BraBLH family was constructed. Subsequently, comparative transcriptomics of heading, non-heading, and GA₃-treated heading plants highlighted multiple differentially expressed BraBLH genes, suggesting that this gene family may contribute to the regulation of leafy head formation in Chinese cabbage. Subsequently, a high-resolution spatiotemporal expression framework for the BraBLH family was constructed. Within this framework, BraBLH5 emerged as a pivotal node integrating GA signaling, peaking during the rosette stage to initiate heading. In contrast, a distinct negative module (BraBLH9/26) was significantly upregulated in the non-heading line. Spatial profiling further revealed functional compartmentalization within the family, where specific members maintained shoot apical meristem identity, whereas others drove inner leaf expansion and incurvature. Furthermore, subcellular localization analysis confirmed that BraBLH5 was localized to the nucleus. Ultimately, this systems-level study elucidates a transcriptome-driven framework for heading, highlighting a GA-mediated BraBLH5 mechanism and providing valuable candidates for Brassica functional genomics. Full article

Cover crops have been recognized as a sustainable practice to improve soil structure and fertility in intensive agroecosystems, yet quantitative evidence on their effects and underlying mechanisms remains limited in high-altitude cereal cropping systems. This study investigated the effects of diverse cover crops on soil physicochemical properties during fallow in southern Tibetan cereal cropping systems, quantified their effect sizes relative to bare fallow, and explored the associations among key soil properties. Results showed significant variations in 0–20 cm soil physicochemical properties among cover crop species. Specifically, the oat (Avena sativa)–common vetch (Vicia sativa) mixture significantly reduced soil pH and increased water-stable aggregate rate (WSAR), total carbon (TC), and C/N ratio compared with turnip (Brassica rapa var. L.) and common vetch monocultures, whereas bulk density, total nitrogen, and soil organic matter (SOM) did not differ among cover crop treatments. Effect size analysis indicated that cover crops significantly reduced soil pH by 3.39% and increased WSAR by 32.85%. Principal component analysis and the piecewise structural equation model revealed that soil pH, WSAR, TC, and SOM collectively explained 86.18% of the observed variation in soil physicochemical properties, with pH significantly and positively affecting TC but negatively influencing WSAR, which in turn strongly promoted TC and thereby greatly enhanced SOM. These findings demonstrate that cover crops substantially improve selected soil physicochemical properties, providing critical evidence for their integration into bare fallow to enhance soil health in high-altitude cereal cropping systems. Full article

Global warming-induced temperature increases adversely affect plant growth, exacerbating agricultural risks and threatening global food security. These challenges are particularly acute for important crops like non-heading Chinese cabbage (NHCC; Brassica campestris L. syn. B. rapa), a nutritionally and economically significant leafy vegetable cultivated worldwide. While breeding for thermotolerance has been explored to stabilize summer supplies, these efforts remain insufficient under complex field conditions, necessitating cost-effective and practical alternatives. Here, we demonstrate that biochar derived from enoki mushroom (Flammulina velutipes) spent mushroom substrate (SMS-BC) significantly alleviates heat-induced growth suppression in greenhouse-cultivated NHCC. SMS-BC alters the soil nutrient profile and enhances available phosphorus and potassium through its unique feedstock properties, including its filamentous architecture and surface functional groups. Furthermore, SMS-BC may reshape microbial community composition of NHCC under heat stress. Our findings establish SMS-derived biochar as an effective soil amendment for alleviating heat stress-induced growth suppression in NHCC. Full article

Quorum sensing (QS) is critically involved in mediating microbial interactions and serves as a central regulatory mechanism in bacterial pathogenesis. As an emerging countermeasure, quorum quenching (QQ) suppresses QS-regulated virulence through enzymatic or chemical disruption of signal systems. N-acyl homoserine lactone (AHL), an evolutionarily conserved QS signal, coordinates the pathogenicity of multiple plant pathogens, particularly Dickeya zeae, which causes soft rot disease in various crops and leads to substantial agricultural losses. In this study, the QQ strain Acinetobacter schindleri XJ-10 was evaluated for its capacity to degrade AHL and attenuate the pathogenicity of D. zeae EC1 in host plants. Notably, strain XJ-10 exhibited efficient AHL degradation at 0.2 mmol/L within 24 h, achieving a degradation efficiency of 98.80%. Subsequently, gas chromatography–mass spectrometry (GC-MS) analysis identified N-hexanoyl-L-homoserine lactone and propanamide as key intermediates during AHL degradation, confirming complete mineralization to CO₂ and H₂O. Based on the structural characterization of AHL and its intermediates, the metabolic pathway within strain XJ-10 was proposed. The degradation pathway initiates with the hydrolysis of the ester ring of N-hexanoyl-L-homoserine lactone, generating N-hexanoyl-L-homoserine. Subsequent carbon–nitrogen bond scission is predicted to yield N-cyclohexyl-propanamide, which is further catabolized to produce hexanamide and propanamide. Furthermore, strain XJ-10 exhibited biocontrol activity against soft rot disease affecting potato (Solanum tuberosum), radish (Raphanus sativus), and Chinese cabbage (Brassica rapa subsp. pekinensis), as its crude enzyme extract effectively reduced disease incidence and severity in planta. While strain XJ-10 showed no detectable acylase activity, it exhibited significant degradation activity against AHL, suggesting a distinct QQ mechanism. Collectively, these findings broaden the scope of QQ-based biocontrol strategies and enhance mechanistic insights into managing bacterial diseases through QS modulation. Full article

The present study evaluated the chemical profiles and bioactivities of 45 rapini (Brassica rapa L.) populations (RA1-RA45) cultivated in Central Greece. Our results suggest that the tested rapini populations differed in their compositional traits, with coefficients of variation (CV) of 11.2% for protein content (21.2–35.1 g/100 g dw), 7.6% for carbohydrate (52.3–66.6 g/100 g dw), and 13.4% for fat content (2.7–5.09 g/100 g dw). Fructose was the most abundant detected compound (2.5–9.7 g/100 g dw) with a CV of 27.3%, while glucose, sucrose and trehalose were also present in descending order. Citric acid was the most important organic acid, which showed a CV of 33.6% (3.0 to 12.8 g/100 g dw), followed by malic, oxalic, and fumaric acid. The prevalent fatty acids were linolenic, palmitic, and α-linolenic acids (up to 11.99%, 14.00%, and 47.10%, respectively). The RA3 population had the highest amounts of α- and γ-tocopherol (7.4 and 1.55 g/100 g dw, respectively), while the antioxidant activity recorded significant variations in the TBARS protocol. Finally, the hydroethanolic extracts of rapini displayed low antimicrobial capacity against most of the bacterial strains and fungi tested. In conclusion, our results highlight the variability in nutritional content and bioactive compounds of the studied rapini germplasm. Populations RA3, RA14, RA31, and RA32 showed promising results for specific compounds, while RA13, RA17, and RA18 had the highest antioxidant capacity. Therefore, the observed genetic variation could be valorized in upcoming breeding schemes aimed at enhancing the phytochemical profile and nutritional value of this underexploited species. Full article

The production of Kimchi cabbage (Brassica rapa L. ssp. pekinensis) is increasingly threatened by concurrent heat and drought stress, which induce physiological disorders and severe heading failure. In this study, we implemented a dual-environment screening strategy to identify robust indicators of heat resilience in an F₂ population. First, seedling-stage heat tolerance was evaluated in a controlled growth chamber using qualitative visual scoring (Scale 1–4) for shoot and root vigor. Second, the population was validated under summer field conditions in South Korea. Machine learning (ML) analysis revealed that the seedling-stage qualitative shoot-to-root (S/R) ratio was the most robust predictor of mature heat resilience, achieving a classification accuracy of 0.770 via SVM algorithms. The study also revealed a strong positive correlation (r = 0.71) between shoot apical meristem (SAM) wilting and localized calcium deficiency (tipburn). Individuals with severe SAM wilting were predominantly associated with severe tipburn and inner-leaf decay. Genome-wide association studies (GWAS) pinpointed the MIZU-KUSSEI 1-like (MIZ1-like) gene on Chromosome 2 as a primary candidate for S/R ratio regulation, potentially acting through the optimization of root hydrotropism. Our findings highlight that qualitative seedling-stage S/R ratio screening, integrated with ML models, serves as an efficient, breeder-friendly tool for early selection of climate-resilient B. rapa cultivars before field transplantation. Full article

This study investigated the effects of far-red (FR, 740 nm) and ultraviolet-A (UV-A, 370 nm) supplementation on the growth and nutritional quality of pak choi (Brassica rapa ssp. chinensis ‘Xiawang’) under different light intensities. Plants were grown under a white LED background light (6500 K) at two light intensities (100 and 400 μmol·m⁻²·s⁻¹) either without (T100 and T400) or with an additional 40 μmol·m⁻²·s⁻¹ of FR or UV-A radiation (T100FR, T100UV-A, T400FR, and T400UV-A). The results demonstrated a significant interactive effect between light intensity and FR/UV-A supplementation. Under low light intensity (T100), both FR and UV-A significantly enhanced biomass accumulation, the net photosynthetic rate, and the content of soluble proteins, soluble sugars, and cellulose. Under a high light intensity (T400), FR and UV-A primarily promoted morphological development (leaf expansion and thickening), photosynthetic performance, and carbohydrate accumulation. Specifically, FR notably promoted petiole elongation while reducing photosynthetic pigment content, whereas UV-A markedly increased the vitamin C content while decreasing nitrate accumulation. In conclusion, both FR and UV-A supplementation effectively improve the growth and quality of pak choi, but, through light-intensity-dependent mechanisms. FR acts mainly via morphological and photosynthetic optimization, whereas UV-A acts as a physiological and nutritional regulator. These findings highlight the complementary roles of FR and UV-A, providing practical guidance for optimizing spectral strategies in controlled environment agriculture (CEA). Full article