Identification of YUC genes associated with leaf wrinkling trait in Tacai variety of Chinese cabbage.

Chinese cabbage (Brassica campestris L. ssp. chinensis (L.) Makino) stands as a widely cultivated leafy vegetable in China, with its leaf morphology significantly influencing both quality and yield. Despite its agricultural importance, the precise mechanisms governing leaf wrinkling development remain elusive. This investigation focuses on 'Wutacai', a representative cultivar of the Tacai variety (Brassica campestris L. ssp. chinensis var. rosularis Tsen et Lee), renowned for its distinct leaf wrinkling characteristics. Within the genome of 'Wutacai', we identified a total of 18 YUCs, designated as BraWTC_YUCs, revealing their conservation within the Brassica genus, and their close homology to YUCs in Arabidopsis. Expression profiling unveiled that BraWTC_YUCs in Chinese Cabbage exhibited organ-specific and leaf position-dependent variation. Additionally, transcriptome sequencing data from the flat leaf cultivar 'Suzhouqing' and the wrinkled leaf cultivar 'Wutacai' revealed differentially expressed genes (DEGs) related to auxin during the early phases of leaf development, particularly the YUC gene. In summary, this study successfully identified the YUC gene family in 'Wutacai' and elucidated its potential function in leaf wrinkling trait, to provide valuable insights into the prospective molecular mechanisms that regulate leaf wrinkling in Chinese cabbage.

Co-hydrothermal carbonization of municipal sludge and agricultural waste to reduce plant growth inhibition by aqueous phase products: Molecular level analysis of organic matter.

The organic matter molecular mechanism by which combined hydrothermal carbonization (co-HTC) of municipal sludge (MS) and agricultural wastes (rice husk, spent mushroom substrate, and wheat straw) reduces the inhibitory effects of aqueous phase (AP) products on pak choi (Brassica campestris L.) growth compared to HTC of MS alone is not clear. Fourier-transform ion cyclotron resonance mass spectrometry was used to characterize the differences in organic matter at the molecular level between AP from MS HTC alone (AP-MS) and AP from co-HTC of MS and agricultural waste (co-Aps). The results showed that N-bearing molecules of AP-MS and co-Aps account for 70.6 % and 54.2 %-64.1 % of all molecules, respectively. Lignins were present in the highest proportion (56.3 %-78.5 %) in all APs, followed by proteins and lipids. The dry weight of co-APs hydroponically grown pak choi was 31.6 %-47.6 % higher than that of the AP-MS. Molecules that were poorly saturated and with low aromaticity were preferentially consumed during hydroponic treatment. Molecules present before and after hydroponics were defined as resistant molecules; molecules present before hydroponics but absent after hydroponics were defined as removed molecules; and molecules absent before hydroponics but present after hydroponics were defined as produced molecules. Large lignin molecules were broken down into more unsaturated molecules, but lignins were the most commonly resistant, removed, and produced molecules. Correlation analysis revealed that N- or S-bearing molecules were phytotoxic in the AP. Tannins positively influenced the growth of pak choi. These results provide new insights into potential implementation strategies for liquid fertilizers produced from AP arising from HTC of MS and agricultural wastes.

A Systematic Review on Effects of Nitrogen Fertilizer Levels on Cabbage (Brassica oleracea var. capitata L.) Production in Ethiopia.

Cabbage (Brassica oleracea var. capitata L.) holds significant agricultural and nutritional importance in Ethiopia; yet, its production faces challenges, including suboptimal nitrogen fertilizer management. The aim of this review was to review the possible effect of nitrogen fertilizer levels on the production of cabbage in Ethiopia. Nitrogen fertilization significantly influences cabbage yield and quality. Moderate to high levels of nitrogen application enhance plant growth, leaf area, head weight, and yield. However, excessive nitrogen levels can lead to adverse effects such as delayed maturity, increased susceptibility to pests and diseases, and reduced postharvest quality. In Ethiopia, small-scale farmers use different nitrogen levels for cabbage cultivation. In Ethiopia, NPSB or NPSBZN fertilizers are widely employed for the growing of various crops such as cabbage. 242 kg of NPS and 79 kg of urea are the blanket recommendation for the current production of cabbage in Ethiopia. The existing rate is not conducive for farmers. Therefore, small-scale farmers ought to utilize an optimal and cost-effective nitrogen rate to boost the cabbage yield. Furthermore, the effectiveness of nitrogen fertilization is influenced by various factors including the soil type, climate, cabbage variety, and agronomic practices. Integrated nutrient management approaches, combining nitrogen fertilizers with organic amendments or other nutrients, have shown promise in optimizing cabbage production while minimizing environmental impacts. The government ought to heed suggestions concerning soil characteristics such as the soil type, fertility, and additional factors such as the soil pH level and soil moisture contents.

The RNA-Binding Protein BoRHON1 Positively Regulates the Accumulation of Aliphatic Glucosinolates in Cabbage.

Aliphatic glucosinolates are an abundant group of plant secondary metabolites in Brassica vegetables, with some of their degradation products demonstrating significant anti-cancer effects. The transcription factors MYB28 and MYB29 play key roles in the transcriptional regulation of aliphatic glucosinolates biosynthesis, but little is known about whether BoMYB28 and BoMYB29 are also modulated by upstream regulators or how, nor their gene regulatory networks. In this study, we first explored the hierarchical transcriptional regulatory networks of MYB28 and MYB29 in a model plant, then systemically screened the regulators of the three BoMYB28 homologs in cabbage using a yeast one-hybrid. Furthermore, we selected a novel RNA binding protein, BoRHON1, to functionally validate its roles in modulating aliphatic glucosinolates biosynthesis. Importantly, BoRHON1 induced the accumulation of all detectable aliphatic and indolic glucosinolates, and the net photosynthetic rates of BoRHON1 overexpression lines were significantly increased. Interestingly, the growth and biomass of these overexpression lines of BoRHON1 remained the same as those of the control plants. BoRHON1 was shown to be a novel, potent, positive regulator of glucosinolates biosynthesis, as well as a novel regulator of normal plant growth and development, while significantly increasing plants' defense costs.

Physicochemical properties and fractal characterizations of the functionalized porous clinoptilolites for controlling alginate delivery in growing cauliflower and leaf mustard.

Using natural clinoptilolite (NCP) as a carrier and alginate (Alg)-calcium as an active species, the porous silicon calcium alginate nanocomposite (Alg-Ca-NCP) was successfully fabricated via adsorption-covalence-hydrogen bond. Its structural features and physicochemical properties were detailed investigated by various characterizations. The results indicated that Alg-Ca-NCP presented the disordered lamellar structures with approximately uniform particles in size of 300-500 nm. Specially, their surface fractal evolutions between the irregular roughness and dense structures were demonstrated via the SAXS patterns. The results elucidated that the abundant micropores of NCP were beneficial for unrestricted diffusing of Alg-Ca, which was conducive to facilitate a higher loading and sustainable releasing. The Ca content of leaf mustard treated with Alg-Ca-NCP-0.5 was 484.5 mg/100g on the 21st day, higher than that by water (CK) and CaCl2 solution treatments, respectively. Meanwhile, the prepared Alg-Ca-NCPs presented the obvious anti-aging effects on peroxidase drought stress of mustard leaves. These demonstrations provided a simple and effective method to synthesize Alg-Ca-NCPs as delivery nanocomposites, which is useful to improve the weak absorption and low utilization of calcium alginate by plants.

Selenium alleviates the adverse effects of microplastics on kale by regulating photosynthesis, redox homeostasis, secondary metabolism and hormones.

Kale is a functional food with anti-cancer, antioxidant, and anemia prevention properties. The harmful effects of the emerging pollutant microplastic (MP) on plants have been widely studied, but there is limited research how to mitigate MP damage on plants. Numerous studies have shown that Se is involved in regulating plant resistance to abiotic stresses. The paper investigated impact of MP and Se on kale growth, photosynthesis, reactive oxygen species (ROS) metabolism, phytochemicals, and endogenous hormones. Results revealed that MP triggered a ROS burst, which led to breakdown of antioxidant system in kale, and had significant toxic effects on photosynthetic system, biomass, and accumulation of secondary metabolites, as well as a significant decrease in IAA and a significant increase in GA. Under MP supply, Se mitigated the adverse effects of MP on kale by increasing photosynthetic pigment content, stimulating function of antioxidant system, enhancing secondary metabolite synthesis, and modulating hormonal networks.

Evaluation of two deep learning-based approaches for detecting weeds growing in cabbage.

BACKGROUND: Machine vision-based precision weed management is a promising solution to substantially reduce herbicide input and weed control cost. The objective of this research was to compare two different deep learning-based approaches for detecting weeds in cabbage: (1) detecting weeds directly, and (2) detecting crops by generating the bounding boxes covering the crops and any green pixels outside the bounding boxes were deemed as weeds. RESULTS: The precision, recall, F1-score, mAP0.5, mAP0.5:0.95 of You Only Look Once (YOLO) v5 for detecting cabbage were 0.986, 0.979, 0.982, 0.995, and 0.851, respectively, while these metrics were 0.973, 0.985, 0.979, 0.993, and 0.906 for YOLOv8, respectively. However, none of these metrics exceeded 0.891 when detecting weeds. The reduced performances for directly detecting weeds could be attributed to the diverse weed species at varying densities and growth stages with different plant morphologies. A segmentation procedure demonstrated its effectiveness for extracting weeds outside the bounding boxes covering the crops, and thereby realizing effective indirect weed detection. CONCLUSION: The indirect weed detection approach demands less manpower as the need for constructing a large training dataset containing a variety of weed species is unnecessary. However, in a certain case, weeds are likely to remain undetected due to their growth in close proximity with crops and being situated within the predicted bounding boxes that encompass the crops. The models generated in this research can be used in conjunction with the machine vision subsystem of a smart sprayer or mechanical weeder. © 2024 Society of Chemical Industry.

Air channels create a directional light signal to regulate hypocotyl phototropism.

In plants, light direction is perceived by the phototropin photoreceptors, which trigger directional growth responses known as phototropism. The formation of a phototropin activation gradient across a photosensitive organ initiates this response. However, the optical tissue properties that functionally contribute to phototropism remain unclear. In this work, we show that intercellular air channels limit light transmittance through various organs in several species. Air channels enhance light scattering in Arabidopsis hypocotyls, thereby steepening the light gradient. This is required for an efficient phototropic response in Arabidopsis and Brassica. We identified an embryonically expressed ABC transporter required for the presence of air channels in seedlings and a structure surrounding them. Our work provides insights into intercellular air space development or maintenance and identifies a mechanism of directional light sensing in plants.

Morphological and molecular diversity in mid-late and late maturity genotypes of cauliflower.

Genetic diversity is the prerequisite for the success of crop improvement programmes. Keeping in view, the current investigation was undertaken to assess the agro-morphological and molecular diversity involving 36 diverse mid-late and late cauliflower genotypes following α-RBD design during winter season 2021-22. Six morphological descriptors predicted as polymorphic using Shannon diversity index with maximum for leaf margin (0.94). The genotypes grouped into nine clusters based on D2 analysis with four as monogenotypic and gross plant weight (32.38%) revealed maximum contribution towards the genetic diversity. Molecular diversity analysis revealed 2-7 alleles among 36 polymorphic simple sequence repeats (SSR) with average of 4.22. Primer BoESSR492 (0.77) showed maximum polymorphic information content (PIC) with mean of 0.58. SSR analysis revealed two clusters each with two subclusters with a composite pattern of genotype distribution. STRUCTURE analysis showed homogenous mixture with least amount of gene pool introgression within the genotypes. Thus, based on morphological and molecular studies, the diverse genotypes namely, DPCaCMS-1, DPCaf-W4, DPCaf-US, DPCaf-W131W, DPCaf-S121, DPCaf-18, DPCaf-13, DPCaf-29 and DPCaf-CMS5 can be utilized in hybridization to isolate potential transgressive segregants to broaden the genetic base of cauliflower or involve them to exploit heterosis.

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Light simplified cultivation and high quality rice are the main directions of rice production in China. Meteorological factors are the most important environmental factors affecting rice growth and yield. Few studies examined the relationship between rice yield and microclimate under different light simplified cultivation modes. To explore the relationship between rice yield and climatic factors (temperature, sunshine and water) at different growth stages of hybrid rice under different forecrops in southwest China, we carried out a split-plot design experiment in 2019 and 2020, with two forecrops of green cabbage and rape as the main plot, and three planting methods, direct-seeding, blanket-transplanting, and artificial transplanting as the subplots, taking Yixiangyou 2115 as the experimental variety. Results showed that compared with rape-paddy cropping system, cabbage-paddy cropping system significantly improved the accumulated temperature and precipitation production efficiency and consequently improved the effective panicles, setting rate, and 1000-grain weight. The yield was increased by 12.7% and 8.3% under cabbage-paddy and rape-paddy cropping system, respectively. Compared with manual transplanting, mechanical transplanting improved effective panicles, production efficiency of radiation, accumulated temperature and precipitation, and the radiation use efficiency of grain during the whole growth period. The mean yield was increased by 4.6% in 2019 and 2020. However, the above parameters of direct-seeding significantly decreased, but the yield decreased by 8.7%. Compared with 2019, mechanical transplanting and artificial transplanting were sown one month earlier in 2020 under the same stubble, which shortened growth period, reduced air temperature, and increased precipitation after flowering, leading to a significant decrease in effective accumulated temperature and light radiation; production efficiency of accumulated temperature, light energy, and precipitation; and utilization efficiency of light energy of grain, spikelets per panicle, setting rate, and 1000-grain weight. However, the yield was significantly reduced. Partial least squares regression analysis was used to establish the production forecast equation of standardized regression coefficients of meteorological factors. There was a positive correlation between rice yield and effective accumulated temperature and total radiation during the growth stage or the whole growth period. In addition, there was a significant negative correlation between rice yield and precipitation during the whole growth period. In conclusion, mechanical transplanting under cabbage-paddy cropping system was a rice planting method that optimised the seasonal sunshine and temperature resources in southwest China. The method facilitated the full utilization of temperature and sunshine resources, resulting in high yield. However, it was not advisable to sow or transplant too early.

Light Intensity and Photoperiod Affect Growth and Nutritional Quality of Brassica Microgreens.

We explored the effects of different light intensities and photoperiods on the growth, nutritional quality and antioxidant properties of two Brassicaceae microgreens (cabbage Brassica oleracea L. and Chinese kale Brassica alboglabra Bailey). There were two experiments: (1) four photosynthetic photon flux densities (PPFD) of 30, 50, 70 or 90 µmoL·m-2·s-1 with red:blue:green = 1:1:1 light-emitting diodes (LEDs); (2) five photoperiods of 12, 14, 16, 18 or 20 h·d-1. With the increase of light intensity, the hypocotyl length of cabbage and Chinese kale microgreens shortened. PPFD of 90 µmol·m-2·s-1 was beneficial to improve the nutritional quality of cabbage microgreens, which had higher contents of chlorophyll, carotenoids, soluble sugar, soluble protein and vitamin C, as well as increased antioxidant capacity. The optimal PPFD for Chinese kale microgreens was 70 µmol·m-2·s-1. Increasing light intensity could increase the antioxidant capacity of cabbage and Chinese kale microgreens, while not significantly affecting glucosinolate (GS) content. The dry and fresh weight of cabbage and Chinese kale microgreens were maximized with a 14-h·d-1 photoperiod. The chlorophyll, carotenoid and soluble protein content in cabbage and Chinese kale microgreens were highest for a 16-h·d-1 photoperiod. The lowest total GS content was found in cabbage microgreens under a 12-h·d-1 photoperiod and in Chinese kale microgreens under 16-h·d-1 photoperiod. In conclusion, the photoperiod of 14~16 h·d-1, and 90 µmol·m-2·s-1 and 70 µmol·m-2·s-1 PPFD for cabbage and Chinese kale microgreens, respectively, were optimal for cultivation.

Chemical Changes in the Broccoli Volatilome Depending on the Tissue Treatment.

The storage of plant samples as well as sample preparation for extraction have a significant impact on the profile of metabolites, however, these factors are often overlooked during experiments on vegetables or fruit. It was hypothesized that parameters such as sample storage (freezing) and sample pre-treatment methods, including the comminution technique or applied enzyme inhibition methods, could significantly influence the extracted volatile metabolome. Significant changes were observed in the volatile profile of broccoli florets frozen in liquid nitrogen at -20 °C. Those differences were mostly related to the concentration of nitriles and aldehydes. Confocal microscopy indicated some tissue deterioration in the case of slow freezing (-20 °C), whereas the structure of tissue, frozen in liquid nitrogen, was practically intact. Myrosinase activity assay proved that the enzyme remains active after freezing. No pH deviation was noted after sample storage - this parameter did not influence the activity of enzymes. Tissue fragmentation and enzyme-inhibition techniques applied prior to the extraction influenced both the qualitative and quantitative composition of the volatile metabolome of broccoli.

Genome-wide identification and expression analysis of the MYC transcription factor family and its response to sulfur stress in cabbage (Brassica oleracea L.).

MYC transcriptional factors are members of the bHLH (basic helix-loop-helix) superfamily, and play important roles in plant growth, biological and abiotic stress. Recent studies have revealed that some MYCs are involved in the synthesis of sulfur-containing secondary metabolites. Cabbage, as a typical sulfur-loving crop and rich in sulfur-containing secondary metabolites, the regulatory relationship between sulfur stress and MYC gene family, related reports are relatively rare. In this study, we conducted the first genome-wide analysis of the MYC transcription factor family of cabbage and identified 17 BoMYC genes. Homology of the 17 BoMYC genes, 12 Arabidopsis, 12 Chinese cabbage, 8 wheat and 21 maize MYC were analyzed using the phylogenetic analysis. Meanwhile, chromosome locations, physical and chemical characteristics, gene structures, conserved motif, cis-element, specific expression in different tissues were studied. Finally, we analyzed the expression of the BoMYC gene under sulfur stress and its GO annotation and KEGG enrichment analysis, determined the expression of the BoMYC gene under hormone treatment and the growth index, photosynthetic capacity and hormone content in the leaves. This study is of great significance for functional identification and revealed the effect of S on BoMYC transcription factors.

AgNPs seed priming accelerated germination speed and altered nutritional profile of Chinese cabbage.

In this study, the performance of AgNPs-priming (20, 40, and 80 mg/L) on the seed germination, yield, and nutritional quality of Chinese cabbage were evaluated. We found that AgNPs-priming at 20 and 40 mg/L for 15 h significantly accelerated seed germination speed and seedling development. Cabbage seeds primed with different concentrations of AgNPs (0, 20, 40, and 80 mg/L) were then planted in a real soil and allowed to grow for 1 month in greenhouse. Results showed that AgNPs-priming at 40 mg/L significantly increased cabbage yield by 44.3%. Gas chromatography-mass spectrometry (GC-MS) combining with sparse partial least squares-discriminant analysis (sPLS-DA) reveals that AgNPs priming altered the metabolite profile of cabbage leaves in a dose-dependent manner, decreasing carbohydrates and increasing nitrogen related compounds. This indicates that the metabolic stimulation during germination stage can influence the entire life cycle of cabbage. The nutritional quality of cabbage edible leaves was evaluated by liquid chromatography with tandem mass spectrometry (LC-MS/MS) and inductively coupled plasma-mass spectrometry (ICP-MS). Results showed that AgNPs-priming at all tested concentrations significantly increased the content of essential amino acids for several folds in cabbage leaves, including alanine, aspartic acid, glutamine, glutamic acid, histidine, isoleucine, leucine, lysine, phenylalanine, proline, serine, threonine, tyrosine, and valine. Meanwhile, AgNPs-priming (40 mg/L) significantly increased iron (Fe) content by 23.8% in cabbage leaves. Ag did not bioaccumulate in edible tissues, indicating the bio-safety of AgNPs-priming. These results suggest that AgNPs-priming is a low-cost and eco-friendly approach to increase crop yield and nutritional quality.

Organelle Comparative Genome Analysis Reveals Novel Alloplasmic Male Sterility with orf112 in Brassica oleracea L.

B. oleracea Ogura CMS is an alloplasmic male-sterile line introduced from radish by interspecific hybridization and protoplast fusion. The introduction of alien cytoplasm resulted in many undesirable traits, which affected the yield of hybrids. Therefore, it is necessary to identify the composition and reduce the content of alien cytoplasm in B. oleracea Ogura CMS. In the present study, we sequenced, assembled, and compared the organelle genomes of Ogura CMS cabbage and its maintainer line. The chloroplast genome of Ogura-type cabbage was completely derived from normal-type cabbage, whereas the mitochondrial genome was recombined from normal-type cabbage and Ogura-type radish. Nine unique regions derived from radish were identified in the mitochondrial genome of Ogura-type cabbage, and the total length of these nine regions was 35,618 bp, accounting for 13.84% of the mitochondrial genome. Using 32 alloplasmic markers designed according to the sequences of these nine regions, one novel sterile source with less alien cytoplasm was discovered among 305 materials and named Bel CMS. The size of the alien cytoplasm in Bel CMS was 21,587 bp, accounting for 8.93% of its mtDNA, which was much less than that in Ogura CMS. Most importantly, the sterility gene orf138 was replaced by orf112, which had a 78-bp deletion, in Bel CMS. Interestingly, Bel CMS cabbage also maintained 100% sterility, although orf112 had 26 fewer amino acids than orf138. Field phenotypic observation showed that Bel CMS was an excellent sterile source with stable 100% sterility and no withered buds at the early flowering stage, which could replace Ogura CMS in cabbage heterosis utilization.

Drought and Subsequent Soil Flooding Affect the Growth and Metabolism of Savoy Cabbage.

An important factor of current climate change is water availability, with both droughts and flooding becoming more frequent. Effects of individual stresses on plant traits are well studied, although less is known about the impacts of sequences of different stresses. We used savoy cabbage to study the consequences of control conditions (well-watered) versus continuous drought versus drought followed by soil flooding and a potential recovery phase on shoot growth and leaf metabolism. Under continuous drought, plants produced less than half of the shoot biomass compared to controls, but had a >20% higher water use efficiency. In the soil flooding treatment, plants exhibited the poorest growth performance, particularly after the "recovery" phase. The carbon-to-nitrogen ratio was at least twice as high, whereas amino acid concentrations were lowest in leaves of controls compared to stressed plants. Some glucosinolates, characteristic metabolites of Brassicales, showed lower concentrations, especially in plants of the flooding treatment. Stress-specific investment into different amino acids, many of them acting as osmolytes, as well as glucosinolates, indicate that these metabolites play distinct roles in the responses of plants to different water availability conditions. To reduce losses in crop production, we need to understand plant responses to dynamic climate change scenarios.

Analysis of SI-Related BoGAPDH Family Genes and Response of BoGAPC to SI Signal in Brassica oleracea L.

Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is not only involved in carbohydrate metabolism, but also plays an important role in stress resistance. However, it has not been reported in Brassica oleracea. In this study, we performed a genome-wide identification of BoGAPDH in B. oleracea and performed cloning and expression analysis of one of the differentially expressed genes, BoGAPC. A total of 16 members of the BoGAPDH family were identified in B. oleracea, which were conserved, distributed unevenly on chromosomes and had tandem repeat genes. Most of the genes were down-regulated during self-pollination, and the highest expression was found in stigmas and sepals. Different transcriptome data showed that BoGAPDH genes were differentially expressed under stress, which was consistent with the results of qRT-PCR. We cloned and analyzed the differentially expressed gene BoGAPC and found that it was in the down-regulated mode 1 h after self-pollination, and the expression was the highest in the stigma, which was consistent with the result of GUS staining. The promoter region of the gene not only has stress response elements and plant hormone response elements, but also has a variety of specific elements for regulating floral organ development. Subcellular localization indicates that the BoGAPC protein is located in the cytoplasm and belongs to the active protein in the cytoplasm. The results of prokaryotic expression showed that the size of the BoGAPC protein was about 37 kDa, which was consistent with the expected results, indicating that the protein was induced in prokaryotic cells. The results of yeast two-hybrid and GST pull-down showed that the SRK kinase domain interacted with the BoGAPC protein. The above results suggest that the BoGAPDH family of B. oleracea plays an important role in the process of plant stress resistance, and the BoGAPC gene may be involved in the process of self-incompatibility in B. oleracea, which may respond to SI by encoding proteins directly interacting with SRK.

Identification of DELLA Genes and Key Stage for GA Sensitivity in Bolting and Flowering of Flowering Chinese Cabbage.

Flowering Chinese cabbage (Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee) is an important and extensively cultivated vegetable in south China, and its stalk development is mainly regulated by gibberellin (GA). DELLA proteins negatively regulate GA signal transduction and may play an important role in determining bolting and flowering. Nevertheless, no systematic study of the DELLA gene family has been undertaken in flowering Chinese cabbage. In the present study, we found that the two-true-leaf spraying of gibberellin A3 (GA3) did not promote bolting but did promote flowering, whereas the three-true-leaf spraying of GA3 promoted both bolting and flowering. In addition, we identified five DELLA genes in flowering Chinese cabbage. All five proteins contained DELLA, VHYNP, VHIID, and SAW conserved domains. Protein-protein interaction results showed that in the presence of GA3, all five DELLA proteins interacted with BcGID1b (GA-INSENSITIVE DWARF 1b) but not with BcGID1a (GA-INSENSITIVE DWARF 1a) or BcGID1c (GA-INSENSITIVE DWARF 1c). Their expression analysis showed that the DELLA genes exhibited tissue-specific expression, and their reversible expression profiles responded to exogenous GA3 depending on the treatment stage. We also found that the DELLA genes showed distinct expression patterns in the two varieties of flowering Chinese cabbage. BcRGL1 may play a major role in the early bud differentiation process of different varieties, affecting bolting and flowering. Taken together, these results provide a theoretical basis for further dissecting the DELLA regulatory mechanism in the bolting and flowering of flowering Chinese cabbage.

Evidence on the Bioaccessibility of Glucosinolates and Breakdown Products of Cruciferous Sprouts by Simulated In Vitro Gastrointestinal Digestion.

Cruciferous vegetables are gaining importance as nutritious and sustainable foods, rich in phytochemical compounds such as glucosinolates (GSLs). However, the breakdown products of these sulfur-based compounds, mainly represented by isothiocyanates (ITC) and indoles, can contribute to human health. In the human digestive system, the formation of these compounds continues to varying extents in the different stages of digestion, due to the contact of GSLs with different gastric fluids and enzymes under the physicochemical conditions of the gastrointestinal tract. Therefore, the aim of the present work was to uncover the effect of gastrointestinal digestion on the release of glucosinolates and their transformation into their bioactive counterparts by applying a simulated in vitro static model on a range of brassica (red radish, red cabbage, broccoli, and mustard) sprouts. In this sense, significantly higher bioaccessibility of ITC and indoles from GSLs of red cabbage sprouts was observed in comparison with broccoli, red radish, and mustard sprouts, due to the aliphatic GSLs proportion present in the different sprouts. This indicates that the bioaccessibility of GSLs from Brasicaceae sprouts is not exclusively associated with the initial content of these compounds in the plant material (almost negligible), but also with the release of GSLs and the ongoing breakdown reactions during the gastric and intestinal phases of digestion, respectively. Additionally, aliphatic GSLs provided higher bioaccessibility of their corresponding ITC in comparison to indolic and aromatic GSLs.

BrcuHAC1 is a histone acetyltransferase that affects bolting development in Chinese flowering cabbage.

Histone acetylation is an important posttranslational modification associated with gene activation. In Arabidopsis, histone acetyltransferase 1 (HAC1) can promote flowering by regulating the transcription of FLOWERING LOCUS C (FLC), a major floral repressor. The size of the full-length cDNA and genomic DNA sequences of the histone acetyltransferase 1 gene (BrcuHAC1) in Chinese flowering cabbage (Brassica rapa syn. campestris ssp. chinensis var. utilis) were 5846 bp and 7376 bp, with an open reading frame (ORF) coding for a peptide with 1689 amino acids. The expression levels of BrcuHAC1 in different tissues and different developmental stages were as follows: flower>leaf>stem>root, and completed bolting and flowering stage>5th true leaf-stage>4th true leaf-stage>3rd true leaf-stage>2nd true leaf-stage>1st true leaf-stage. Silencing of BrcuHAC1 resulted in slow growth, and delayed bolting and flowering time in Chinese flowering cabbage. Molecular analysis showed that the mRNA level of FLC was increased, indicating that the delayed flowering phenomenon was mediated by FLC in the silenced group. In contrast, the expression levels of the autonomous-pathway genes were not significantly affected in the silenced group. In addition, the histone modification of FLC chromatin was also not affected in the silenced group. FLC is not the direct target gene of BrcuHAC1. However, BrcuHAC1 may affect the bolting and flowering time of Chinese flowering cabbage through the epigenetic modification of upstream factors of FLC.