The storability of two different varieties of Chinese cabbage was evaluated. Results indicated that' Beijing New No.3′ (N3) exhibited longer storage life and better postharvest quality than' Beijing ...New No.1′ (N1). Relative to N1, N3 had a lower rate of fresh weight loss and rot development during the latter period of storage (125 days). Ethylene generation and the respiration rate of N3 cabbage were also lower than they were in N1 cabbage over the entire storage period. Chlorophyll (Chl) content was lower in N3 cabbage and the ACS, ACO and ACC enzyme activity were also lower than those in N1 cabbage. Additionally, the relative expression level of COL1, JAZ, MYC2, LOX, ACS, ACO, EBF, EIN3, ERF, and MKK in N1 Chinese cabbage increased, during storage in both varieties, while the relative expression of CDPK, COL1, CAML, and PAL decreased. These results provide valuable information on the storability and quality of Chinese cabbage, especially in relationship to plant hormone levels. The collective data indicate that N3 Chinese cabbage has better storability and postharvest quality than N1.
•The storability of two different varieties of Chinese cabbage was evaluated.•N3 had better storage longevity and postharvest quality compared with N1.•Ethylene emissions of N3 cabbage were lower than N1 cabbage during storage period.•Respiration rate of N3 cabbage were lower than N1 cabbage during storage period.•Chl content was lower in N3 cabbage.
The aim of this study is to analyze the variations in the plant-available nitrogen (PAN) concentrations in the soil profile. Different fertilizers were applied for Chinese cabbage plantation (CCP) in ...the experimental fields of the Shunyi region. The treatments used for the comparative analysis are (i) no fertilizer and plantation (NVP), (ii) no fertilizer with CCP (CTP), (iii) fertilization as urea (URP), and (iv) potassium nitrate (KNP) and chicken manure (CMP) with CCP. It was concluded that the yield was significantly high in URP, CMP, and KNP as compared to CTP. In URP, maximum PAN in soil layers 0-60 cm was recorded during crop production and in 60-100 cm after harvesting as compared to other treatments. Significant variations in soil pH and electrical conductivity (EC) for the soil profile (0-100 cm) from the initial values with respect to time and treatments were observed. CMP showed maximum ammonium in the upper layers of 0-60 cm throughout the season, whereas minimum PAN was observed in NVP but increased in lower layers of 60-100 cm. In general, all fertilizers raised the PAN below the soil 60-100 cm which indicates their potential for nitrate leaching (NL).
To utilize Chinese cabbage waste (CCW) recovered from the pickle industry, a simple medium named Chinese cabbage medium (CCM) was developed for Levilactobacillus growth and γ-aminobutyric acid (GABA) ...production. The optimal medium compositions were 30% Chinese cabbage waste extracts (CCWE), 3% glucose, 0.25% yeast extract (YE), 0.25 X salts (0.25% sodium acetate, 0.1% sodium citrate, 0.1% ammonium sulfate, 0.005% magnesium sulfate and 0.0025% manganese sulfate), and initial pH 5.0 adjusted by HCl. L. brevis was incubated in this medium with 1% monosodium glutamate (MSG) at 30 °C for 24 h. Cell counts reached 4.16 × 109 CFU/ml, and the control results from MRS medium was 4.07 × 109 CFU/ml. GABA conversion rate at 18 h of this medium was 99.12%, higher than the MRS medium of 95.01%. Fructose and maltose were beneficial to the growth of L. brevis, but glucose was conducive to GABA synthesis. To obtain a high yield of GABA, CCM medium with 10% MSG was optimized by response surface methodology and resulted in 21.84% CCWE, 5.5% glucose, 4% YE, 1 X salt, 0.2% disodium phosphate, and initial pH of 4.5. GABA conversion rate reached 100% at 48 h with a final yield of 55.1 g/L.
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•Fructose and maltose were beneficial to L. brevis growth.•Glucose was conducive to GABA synthesis.•CCM with 1% MSG were 30% CCWE, 3% glucose, 0.25% YE, 0.25 X salt and initial pH 5.0.•CCM with 10% MSG was optimized by RSM and GABA yield reached 55.1 g/L at 48 h.
•The estimation models constructed by spectra and multispectral imaging combined with various machine learning algorithms were compared.•A one-dimensional convolutional neural network model based on ...spectral data was established.•A two-dimensional convolutional neural network model based on multispectral images was established.•Spectra and multispectral images were combined with deep learning to achieve the estimation of multiple indicators, such as photosynthetic pigments and SPAD.
The contents of photosynthetic pigment, which directly affect the growth of crops, could be evaluated with spectral and multispectral imaging technologies in an accurate and rapid way. For commodity germplasm resources on the market, the estimation of photosynthetic pigments and soil and plant analyzer development (SPAD) value was accomplished using the two techniques combined with machine learning. The spectrometer used in this study employed 781 bands from 320 nm to 1100 nm, and a multispectral imaging camera was used to acquire images in visible and near-infrared. Convolutional neural network (CNN), multiple linear regression (MLR) and generalized linear model (GLM) were used to establish the machine learning models, which established by preprocessed spectral data or 4-channel multispectral images. For estimating photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll and carotenoids), the GLM model established by spectral data was the optimal among all the models. For the SPAD optimal estimation model, the GLM model established by the spectral data and CNN model established by the multispectral images were fair. The R2 and RMSE of the CNN model validation set in estimating SPAD were 0.87 and 2.31, respectively. The R2 and RMSE of the GLM model validation set in estimating SPAD were 0.88 and 2.39, respectively. By combining two techniques with different machine learning methods, a comprehensive analysis of photosynthetic pigments and SPAD was accomplished in this paper.
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•Plasmodiophora brassicae manipulates host sugar transporters.•BrSWEET genes up-regulate in Chinese cabbage upon plasmodiophora brassicae infection.•Functional analysis reveals ...BrSWEET genes' role in sugar transport and clubroot disease susceptibility.•BrSWEET1a, BrSWEET11a, BrSWEET12a identified as key genes in response to P. brassicae.
Plasmodiophora brassicae, the causative agent of clubroot disease, establishes a long-lasting parasitic relationship with its host by inducing the expression of sugar transporters. Previous studies have indicated that most BrSWEET genes in Chinese cabbage are up-regulated upon infection with P. brassicae. However, the key BrSWEET genes responsive to P. brassicae have not been definitively identified. In this study, we selected five BrSWEET genes and conducted a functional analysis of them. These five BrSWEET genes showed a notable up-regulation in roots after P. brassicae inoculation. Furthermore, these BrSWEET proteins were localized to the plasma membrane. Yeast functional complementation assays confirmed transport activity for glucose, fructose, or sucrose in four BrSWEETs, with the exception of BrSWEET2a. Mutants and silenced plants of BrSWEET1a, -11a, and -12a showed lower clubroot disease severity compared to wild-type plants, while gain-of-function Arabidopsis thaliana plants overexpressing these three BrSWEET genes exhibited significantly higher disease incidence and severity. Our findings suggested that BrSWEET1a, BrSWEET11a, and BrSWEET12a play pivotal roles in P. brassicae-induced gall formation, shedding light on the role of sugar transporters in host-pathogen interactions.
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•The highest yield of VFAs from CCW was achieved at pH 6.0.•The proportion of hexanoate at pH 6.0 accounted for 30.4% of the TVFAs.•The increase of hexanoate was accompanied with the ...decline of ethanol and butyrate.•Clostridium IV, Ruminococcus, and Candida could be related to hexanoate production.
The effects of pH on the production of volatile fatty acids (VFAs) and the evolution of microbial community structure were studied via anaerobic fermentation of Chinese cabbage waste. The results showed that the concentration of total VFAs was highest at 20,241.4 mg COD/L at pH 6.0, followed by pH 7.0. Ethanol, acetate and butyrate were dominant under the acidic condition. The main products at pH 7.0 were acetate, propionate, and butyrate. Ethanol, acetate and butyrate were rapidly produced during the initial stage. The hexanoate concentration increased quickly from day 6 due to the chain extension between ethanol and butyrate, and was 4,885.1 mg COD/L on day 8, accounting for 30.4% of the total VFAs. As fermentation was extended, Bacteroidia and Clostridia were dominant at pH 6.0 and the uncontrolled pH, respectively. Clostridium IV, Ruminococcus, and Candida, were suspected to be related to hexanoate production.
Non-heading Chinese cabbage (NHCC, Brassica rapa ssp. chinensis) is an important leaf vegetable grown worldwide. However, little is known about the molecular mechanisms underlying tolerance for ...extreme temperature in NHCC. The limited availability of NHCC genomic information has greatly hindered functional analysis and molecular breeding.
Here, we conduct comprehensive analyses of cold and heat treatments in NHCC using RNA-seq. Approximately 790 million paired-end reads representing 136,189 unigenes with N50 length of 1705 bp were obtained. Totally, 14,329 differentially expressed genes (DEGs) were detected. Among which, 10 DEGs were detected in all treatments, including 7 up-regulated and 3 down-regulated. The enrichment analyses showed 25 and 33 genes were enriched under cold and heat treatments, respectively. Additionally, 10,001 LncRNAs were identified, and 9,687 belonged to novel LncRNAs. The expression of miRNAs were more than that of pri-miRNAs and LncRNAs. Furthermore, we constructed a coexpression network for LncRNAs and miRNAs. It showed 67 and 192 genes were regulated by LncRNAs under cold and heat treatments, respectively. We constructed the flowchart for identifying LncRNAs of NHCC using transcriptome. Except conducting the de novo transcriptome analyses, we also compared these unigenes with the Chinese cabbage proteins. We identified several most important genes, and discussed their regulatory networks and crosstalk in cold and heat stresses.
We presented the first comprehensive characterization for NHCC crops and constructed the flowchart for identifying LncRNAs using transcriptome. Therefore, this study represents a fully characterized NHCC transcriptome, and provides a valuable resource for genetic and genomic studies under abiotic stress.
Protoplast-based transient gene expression system has been widely used in plant genome editing because of its simple operation and less time-consuming. In order to establish a universal ...protoplast-based transient transfection system for verifying activities of genome editing vectors containing targets in Brassica, we systematically optimized factors affecting protoplast isolation and transient gene expression. We established an efficient protoplast-based transient gene expression system (PTGE) in Chinese cabbage, achieving high protoplast yield of 4.9 × 105 · g−1 FW, viability over 95%, and transfection efficiency of 76%. We showed for the first time that pretreatment of protoplasts with a hypotonic MMG could significantly enhance the transfection efficiency. Furthermore, protoplasts incubated at 37 °C for 6 min improved the transfection efficiency to 86%. We also demonstrated that PTGE worked well (more than 50% transfection efficiency) in multiple Brassica species including cabbage, Pak Choi, Chinese kale, and turnip. Finally, PTGE was used for validating the activities of CRISPR/Cas9 vectors containing targets in Chinese cabbage, cabbage, and pak choi, demonstrating the broad applicability of the established PTGE for genome editing in Brassica crops.
Flowering Chinese cabbage is one of the most economically important stalk vegetables. However, the molecular mechanisms underlying bolting, which is directly related to stalk quality and yield, in ...this species remain unknown. Previously, we examined five key stem development stages in flowering Chinese cabbage. Here, we identified a gene, BcSOC1 (SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1), in flowering Chinese cabbage using transcriptome analysis, whose expression was positively correlated with bolting. Exogenous gibberellin (GA3) and low-temperature treatments significantly upregulated BcSOC1 and promoted early bolting and flowering. Additionally, BcSOC1 overexpression accelerated early flowering and stem elongation in both Arabidopsis and flowering Chinese cabbage, whereas its knockdown dramatically delayed bolting and flowering and inhibited stem elongation in the latter; the inhibition of stem elongation was more notable than delayed flowering. BcSOC1 overexpression also induced cell expansion by upregulating genes encoding cell wall structural proteins, such as BcEXPA11 (cell wall structural proteins and enzymes) and BcXTH3 (xyloglucan endotransglycosidase/hydrolase), upon exogenous GA3 and low-temperature treatments. Moreover, the length of pith cells was correlated with stem height, and BcSOC1 interacted with BcAGL6 (AGAMOUS-LIKE 6) and BcAGL24 (AGAMOUS-LIKE 24). Thus, BcSOC1 plays a vital role in bolting and stem elongation of flowering Chinese cabbage and may play a novel role in regulating stalk development, apart from the conserved function of Arabidopsis SOC1 in flowering alone.
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