Identification and functional characterization of BrcLL1, a candidate gene controlling leaf lobing in non-heading Chinese cabbage (Brassica rapa subsp. chinensis).

Cerium induces biphasic responses in Brassica rapa L. through modulated photosynthesis, oxidative homeostasis, and gene expression.

Spinosyn α4, a potential insecticide against Plutella xylostella from Saccharopolyspora sp. AN150100.

Carbon dots promote plant growth via coordinated regulation of nutrient uptake and photosynthesis: Evidence from multivariate modeling.

Laser light as a novel postharvest strategy to suppress chlorophyll degradation and oxidative stress in pakchoi (Brassica rapa subsp. Chinensis)

ABSTRACT Application of low levels of boron (B) to soil can suppress clubroot symptoms slightly on brassica crops, but phytotoxicity increases rapidly as rates of added B increase. Tolerance to added B has been reported previously in Brassica rapa and more recently in B. napus. We investigated B uptake, speciation, and storage in sensitive and tolerant lines as part of a wider examination of the potential for use of B-tolerance in B. napus to reduce clubroot severity. The current study demonstrated that B speciation and translocation in B. napus differed between B-tolerant and B-sensitive lines. A higher proportion of B was incorporated into nitrogen-containing compounds in root tissues of the putative tolerant lines relative to sensitive lines grown under normal condition (control). In treatments that received added B, trigonally coordinated B-O compounds were dominant in all plant tissues with the presence of tetragonally coordinated B-O compounds. B-tolerant lines accumulated less B in shoots relative to B-sensitive lines when exposed to excess B, which would help plants avoid B phytotoxicity. This study supports previous suggestions that application of B onto a B-tolerant cultivar could potentially be included as one strategy in an integrated crop strategy to reduce clubroot severity.

ABSTRACT Clubroot is a global soilborne disease caused by Plasmodiophora brassicae that severely affects cruciferous crops. Currently, there are no effective control measures to completely eliminate pathogens in the field. Pot experiments have shown that treatment with Mesorhizobium huakuii 7653 R can relieve clubroot symptoms. However, whether M. huakuii 7653 R can be used in the field to control clubroot disease is unclear, and the mechanism of its resistance remains largely unknown. We conducted two seasons of field trials with Brassica napus and found that M. huakuii 7653 R treatment significantly reduced clubroot disease severity, and that the agronomic traits at the seedling, flowering, and harvesting stages were significantly improved compared to the control group. The average yield per hectare, thousand grain weight, and oil content increased by 83.1%, 10.4%, and 3.7%, respectively. M. huakuii 7653 R also enhanced the resistance and yield of the cruciferous plant Brassica campestris var. purpuraria to clubroot. We characterized the composition and structure of the endophytic microbiota using bacterial 16S sequencing, and showed that treatment with M. huakuii 7653 R shaped the structure of endophytic bacterial communities. The relative abundances of Actinobacteria and Bacteroidetes, which are resistant to oxidative stress, were enriched in the co-inoculation with M. huakuii 7653 R and P. brassicae on B. napus. Transcriptome data indicated that genes related to plant immunity, nitrogen uptake and metabolism were significantly up-regulated by co-inoculation with M. huakuii 7653 R and P. brassicae. Our findings provide a theoretical basis for the widespread application of M. huakuii 7653 R in clubroot biocontrol.

Jasmonate-ZIM domain (JAZ) proteins act as repressors in the jasmonic acid (JA) signaling pathway and also function as plant-specific proteins participating in plant growth and development, stress response, and defense. In our study, a total of 25 JAZ genes were identified in B. rapa based on their conserved domains. First, the primary characteristics were surveyed, including the lengths of the CDS and proteins, molecular weights, and isoelectric points. Next, a phylogenetic tree of JAZ proteins among B. rapa, A. thaliana, O. sativa, B. oleracea, and B. napus was constructed, which revealed that these proteins cluster into four groups based on sequence homology rather than by species. Synteny analysis of JAZ genes among these species demonstrated that the highest number of collinear pairs was found between B. rapa and B. napus. Most BrJAZ genes were highly expressed in root, stem, and leaf. Moreover, the expression levels of BrJAZ1a and BrJAZ6b were induced by drought, high salt, black rot, and MeJA. Over-expressed these genes in A. thaliana lines enhanced their tolerance to drought and high salt stress, which was associated with higher enzymatic activities of SOD and POD. Both BrJAZ1a-GFP and BrJAZ6b-GFP were localized in the nucleus.

Verticillium wilt is an emerging threat to Brassicaceae crops worldwide, yet information on the species diversity and pathogenicity of Verticillium on Napa cabbage (Brassica rapa subsp. pekinensis) in South Korea remains limited. During surveys in 2020 and 2021, patches of wilted Napa cabbage plants were observed in highland cultivation regions, with disease incidence ranging from 1 to 10%. Twenty symptomatic plants were collected, and fifteen fungal isolates were obtained through tissue culture. Morphological observations and multilocus phylogenetic analyses based on four loci (ACT, EF, GPD, and TS) identified two species, V. dahliae and Verticillium longisporum (lineages A1/D1). Morphologically, V. longisporum produced longer conidia (>6.1 μm) and elongate microsclerotia, whereas V. dahliae produced shorter conidia (<6.0 μm) and spherical microsclerotia. Growth assays demonstrated that V. longisporum grew optimally at 22 °C and V. dahliae at 25 °C, with V8 agar supporting the best growth of both species. Pathogenicity tests on Napa cabbage seedlings confirmed that both species caused typical wilt symptoms, including leaf yellowing, senescence, and stunted growth. To our knowledge, this is the first report of V. longisporum associated with Verticillium wilt of Napa cabbage in South Korea. While Verticillium wilt has so far been confined to highland cultivation areas, considering the predominance of V. longisporum in autumn–winter cropping regions in Japan, continued monitoring in similar Korean production regions will be essential. These findings provide new insights into the distribution, morphology, and pathogenicity of Verticillium species, contributing to the development of effective management strategies for Napa cabbage production.

Comprehensive analysis of the lipid characteristics, nutritional potential and in vitro digestive behavior of Brassica rapa L. seed oil.

ABSTRACT Brassica rapa subsp rapa L., a plant used in both traditional medicine and cuisine, produces a diverse array of valuable metabolites and hosts a variety of endophytic organisms. In this study, we characterized the metabolic profiles of four fungal endophytes isolated from B. rapa and evaluated the immunomodulatory potential of their metabolites in a mouse model. The investigation focused on the metabolites' ability to enhance immunity by activating genes associated with the NF-κB and inflammatory pathways. Our results indicated that the metabolic composition of the endophyte strain PR10 was distinct from the other three isolates, with a notable enrichment in amino acids. Moreover, PR10 extracts potently activated genes related to the NF-κB and inflammatory pathways, an effect consistent with that observed for the B. rapa plant itself. These findings provide new insights into the functional interplay between B. rapa and its endophytes in modulating inflammatory and immune responses.

As a primary macronutrient, nitrogen is integral to plant growth and regulates their development; ammonium transporters (AMTs) mediate nitrogen absorption and its involvement in metabolism. In this study, nine BcAMT genes were identified in flowering Chinese cabbage (Brassica campestris) and were systematically categorized into two subfamilies. Their evolutionary relationships, conserved motifs, chromosomal distribution, cis-regulatory elements, and expression profiling were systematically characterized. RNA sequencing and quantitative real-time PCR (qRT-PCR) analyses demonstrated that BcAMT1.1 was abundantly expressed in roots, leaves, and stems of flowering Chinese cabbage and was markedly upregulated under nitrogen deficiency. Assessing subcellular location using GFP fusion demonstrated that BcAMT1.1 localized to the plasma membrane. Functional assays identified heterologous expression in the yeast mutant strain 31019b, and transgenic Arabidopsis validated that BcAMT1.1 acted as a functional ammonium transporter. Compared with the wildtype, overexpressing BcAMT1.1 promoted seedling growth, enhanced NH4+ influxes and NO3− effluxes under low-nitrogen conditions, and significantly increased the transcription levels of key nitrogen assimilation genes (i.e., AtGLN1.1, AtGLN2, AtGDH2). Collectively, our findings enhance the fundamental understanding of BcAMT gene functions and highlight BcAMT1.1 as a crucial component in nitrogen uptake and assimilation under low-nitrogen conditions, providing valuable genetic resources for improving nitrogen efficiency in vegetable crops.

Cnidium monnieri is a valuable functional plant with significant potential for green pest control. However, its large-scale application is limited by its low and uneven seed germination in fields. To determine the factors that affect the germination of C. monnieri seeds, we examined its seed viability, germination percentage and germination speed index (GSI) after seed-coat treatments, water permeability, and the types and activity of endogenous inhibitory substances in C. monnieri seeds. The results indicated that the seed viability of C. monnieri is 95%, but the germination percentage was relatively low (12.60%). Seed coat removal significantly enhanced both the germination percentage and the GSI, but had no significant effect on water absorption rate. Moreover, ethyl acetate extracts completely inhibited the seed germination of the control non-dormant Brassica rapa subsp. rapa, while diethyl ether extracts showed moderate suppression, and petroleum ether extracts exhibited the weakest effect. And the three endogenous inhibitory substances, i.e., dibutyl phthalate, 2,6-di-tert-butylphenol, and 2,4-di-tert-butylphenol significantly reduced the seed germination, seedling height and root length of B. rapa, indicating their high inhibitory efficiency on seed germination. Our study demonstrates that the mechanical barrier of the seed coat and the presence of potent endogenous germination inhibitory substances are the key factors influencing the germination of C. monnieri seeds. These findings provide a theoretical basis for promoting seed germination of C. monnieri, which enhance its application value as functional plant for green pest control.

Polyploidy considerably influences eukaryotic evolution, often leading to structural and functional imbalances during the merging of subgenomes. Studies have demonstrated asymmetric subgenome dominance in polyploids, but the effects of accessible chromatin regions (ACRs) and DNA methylation-especially in resynthesized allotriploids-remain underexplored. In this study, we generated two Brassica allotriploid hybrids by crossing Brassica napus (AnAnCnCn) with Brassica rapa (ArAr). Among the three subgenomes (Ar, An, and Cn) in F1 hybrids, gene expression was highest in the An subgenome; however, the Cn subgenome exhibited greater dominance among homoeologous triplet genes (hGenes), which correlated with ACRs in proximal and genic regions of these dominant triplets. Variations in DNA methylation alone did not fully explain the subgenomic expression biases; however, RNA-directed DNA methylation pathway genes contributed to the differences in methylation levels. Mutants of BnaDCL3 and BnaRDR2 revealed the roles of their encoded proteins in regulating non-CG methylation through 24-nt siRNA interactions in the An and Cn subgenomes. We detected higher methylation levels in the gene bodies of Cn homologs in B. napus, regardless of their expression levels. Overall, this work reveals complex interactions among ACRs, DNA methylation, and subgenome dominance, advancing our understanding of polyploid genome regulation in resynthesized allotriploids.

Leaf shape is a vital economic and developmental trait of the leafy vegetable Chinese cabbage (Brassica rapa L. subsp. pekinensis). However, the molecular basis of leaf shape determination remains unclear. Here, we identified an incompletely dominant major quantitative trait locus qBrLLA10 on chromosome A10 in B. rapa. Map-based cloning revealed that BrRCO, encoding a HD-Zip transcription factor, is the causal gene underlying lobed leaf formation in B. rapa. Sequence analysis of parental alleles revealed abundant variations in the promoter region of BrRCO, which are responsible for leaf shape differentiation between the two parents. Ectopic BrRCO overexpression in Arabidopsis led to deeply lobed leaves, and leaf lobe development was blocked when BrRCO expression was down-regulated in virus-induced gene silencing assays. Synteny analysis of BrRCO loci in 12 representative B. rapa accessions revealed highly variable promoter regions and relatively conserved coding regions of BrRCO; these results suggest that cis-regulatory evolution underlies the functional diversification of the RCO locus in different species. Taken together, our findings revealed that BrRCO positively regulates leaf lobe formation in B. rapa, and cis-regulatory element modifications result in functional variation among different species, providing a novel insight into improvement in leaf shape in Chinese cabbage and other Brassica species.

Whole-genome duplication is a key evolutionary mechanism influencing gene regulation and trait development; however, how successive genome duplications reshape chromatin at the genome-wide scale and thereby drive phenotypic innovation remains unclear. To dissect the effects of genome doubling on chromatin dynamics, gene expression, and associated trait differences, monoploid, diploid, and autotetraploid Brassica rapa L. ssp. pekinensis lines are generated with an identical genomic background and performed integrative analyses using ATAC-seq, ChIP-seq (H3K4me3, H3K27ac, H3K27me3), and RNA-seq. By establishing this uniform ploidy series, nonlinear and stage-specific chromatin and transcriptional reprogramming during autopolyploidization are revealed. Increased ploidy reprogrammed chromatin accessibility, characterized by reduced proximal and expanded distal regions, with effects particularly pronounced during the monoploid-to-diploid transition. Corresponding changes in H3K4me3 modifications near transcription start sites alter global gene expression. Numerous transcription factor genes are identified, of which BrGRF13 and BrARF11 are crucial regulators of leaf size and polarity during head development. Overall, this study elucidates the molecular basis by which ploidy variation drives chromatin remodeling and phenotypic divergence, providing new insights into how genome duplication shapes plant traits and informs polyploid crop improvement.

In farmland, especially in the high-quality production region, although smaller quantities of agrochemicals are applied compared to conventional farming, the repeated use of chemical fertilizers and other organic amendments can increase the accumulation of heavy metals (HMs) in soils and plants and raise human health risks for consumers. Our study provides a detailed overview of the status of soils, the soil-crop transfer, and health risks of HMs (Cr, Cu, Zn, Ni, Pb, and Cd) in a vegetable planting region (with the two studied Brassica species: Brassica rapa var. Parachinensis and Brassica rapa subsp. Chinensis), in Me Linh commune, Hanoi, Vietnam. Soil contamination assessment indicates a non-HM pollution. However, the total and bioavailable fractions of HMs can exert an impact on HM bioaccumulation tendencies in vegetables. Although low transfer factors and no significant bioaccumulation of HMs in studied vegetables are observed, the high levels of Pb (more than twice as high as the permissible FAO/WHO standards), Cr, and Cd (almost reach the standards of the FAO/WHO) in the vegetables imply potential impact on product quality and human health, especially for children. The calculated Hazard Indexes (HIs) based on total HM contents in vegetables for adults are less than 1, indicating no elevated health risk. Meanwhile, the HM-related health risk assessment indicates potentially adverse health effects (HI = 6.35 for Brassica rapa var. Parachinensis and HI = 7.85 for Brassica rapa subsp. Chinensis) for children. Total Cr and Pb are the major contributors to the HI in both vegetables. Overall, an understanding of the potential enrichment of HMs in soils and vegetables can contribute to the safe and environmentally sustainable agriculture.

Prior to 1980, experimental induction of polyploidy led to the release of several tetraploid Brassica rapa ssp. rapa as turnip cultivars. Most experimentally induced polyploids are meiotically unstable and show reduced fertility, but we hypothesized that these commercially propagated turnip lines should have restored fertility and stabilized meiosis. We collected all available B. rapa lines listed as tetraploid from germplasm banks, and subsequently investigated chromosome karyotypes, meiotic chromosome behaviour and fertility. Unexpectedly, all accessions showed unstable meiosis: the average tetravalent frequency per meiosis per plant ranged from 4.8 to 6.4 per line. Using chromosome-specific fluorescence in situ hybridisation probes, we found that most chromosomes showed similar frequencies of tetravalent formation except for chromosomes A3 and A6, which predominantly formed tetravalents (>90%). Of the 21 individuals sequenced (one per accession), approximately half (9/21) were aneuploid (loss or gain of a whole chromosome), and two displayed additional chromosomal rearrangements. We nevertheless observed no significant phenotypic abnormalities or reductions in fertility (although all accessions were self-incompatible). Our findings indicate that stabilizing meiosis may not always be necessary to produce relatively fertile and homogeneous polyploid populations, and point at self-incompatibility as a possible mechanism helping prevent fixation of undesirable aneuploid karyotypes.

Aiming at problems such as Chinese cabbage seeds’ small size, easy breakage, light quality, difficulty realizing single grain precision sowing, injury, and poor uniformity of seed discharge, a kind of groove-spoon type precision seed metering device with a guide ring combining a groove U-hole for Chinese cabbage was proposed. The seeding spoon features a tapered platform design, with a smaller upper section and a larger lower section. Preventing seed buildup during filling and enhancing single-seed sowing probability. It reduces seed damage caused by gravity-based seed clearance, incorporates seed guide rings and discharge channels to assist seed release, and improves seed distribution uniformity. The key structural parameters and working parameters of the seed metering device were determined through theoretical analysis, and the force analysis of cabbage seeds in filling, clearing, guiding, and casting was carried out. The discrete element single factor simulation test and quadratic regression orthogonal rotation combination test were conducted with U-hole diameter, U-hole depth, and inclination angle of the top of the seed scoop as test factors, and qualified rate, multiple rate and leakage rate as test indexes, the test results show that when the U-hole diameter is 2.32 mm, the U-hole depth is 1.76 mm. The inclination angle of the top of the seed spoon is 15.34°, and the seed metering device works optimally. Based on the simulation test, bench test, and field test under the optimal parameter combination, the results of the simulation test showed a qualified rate of 92.22%, a multiple rates of 4.21%, and a leakage rate of 3.57%; the qualified index of the bench test result 91.33%, the multiple indexes is 4.89%, and the leakage index is 3.78%, and the error value between the simulation and the bench test result is small, which proves the reliability of the simulation test; when the forward speed of the planter was 0.4–1.2 m/s, the qualified index of the field test was 89.90%, the multiple indexes was 6.06%, and the leakage index was 4.04%, which meets the planting requirements of Chinese cabbage precision direct seeding.

Urban farming and controlled-environment agriculture have become critical strategies for sustainable food production. This study investigates the effects of overexposing blue and purple LED light on the growth of Brassica rapa (petchay) and Ipomoea aquatica (water spinach) under controlled outdoor conditions. The research evaluated plant height, number of leaves, leaf length, and leaf width across three lighting treatments: natural sunlight, blue LED, and purple LED. Using one-way ANOVA and post-hoc analysis, significant differences were observed in selected growth parameters. Blue LED light significantly increased the plant height of Water Spinach (mean = 14.82 cm, p = 0.0339), while purple LED light significantly enhanced the number of leaves in Petchay (mean = 8.46, p &lt; 0.001). No significant differences were found in leaf length and width across treatments for both crops. These findings suggest that specific LED wavelengths can improve particular growth traits depending on crop type. The study provides a basis for optimizing artificial lighting strategies in controlled agriculture and urban farming systems.