Chinese Cabbage Seedlings Research Articles

Transcriptome analysis revealed pivotal transporters involved in the reduction of cadmium accumulation in pak choi (Brassica chinensis L.) by exogenous hydrogen-rich water

Hydrogen-rich water (HRW) has been widely used in research on plant resistance to Cd. However, the underlying molecular mechanism of HRW in ameliorating cadmium stress in vegetables is largely unknown. In this study, the RNA-sequencing analyses were used to characterize the role of HRW in the alleviation of Cd toxicity in Chinese cabbage seedlings. Based on the obtained results, two genes encoding metal ionic transporters, BcIRT1 and BcZIP2 were ultimately selected out. Then, a systematic validation of the metal ion transport function of these two ZIP-encoding genes of pak choi were performed via a yeast transformation system. The results showed that BcIRT1 and BcZIP2 increased the sensitivity of different yeast mutant strains to relative metal ionic stresses and facilitated the accumulation of metal ions (Cd2+, Mn2+, Zn2+, and Fe2+) in yeast; thus, it suggests that BcIRT1 and BcZIP2 probably have the ability to transport Cd2+, Mn2+, Zn2+ and Fe2+ in pak choi. The time-course and concentration-dependent expression profiles of BcIRT1 and BcZIP2 showed that as time with HRW increased, the effectiveness of the repression on the expression of BcIRT1 and BcZIP2 increased, and as the seedlings were exposed to increased Cd concentrations, the inhibition of BcIRT1 and BcZIP2 by HRW was also increased. Over all, these findings provide new insights into the genome-wide transcriptome profiles in pak choi and show that HRW reduced Cd uptake probably through inhibiting the expression of transporters related to Cd absorption, BcIRT1 and BcZIP2.

Plasmodiophora brassicae root hair interaction and control by Bacillus subtilis XF-1 in Chinese cabbage

Clubroot caused by Plasmodiophora brassicae Woron is one of the most destructive diseases of Chinese cabbage (Brassica napus). A highly potent strain of Bacillus subtilis, XF-1, which was isolated from the rhizosphere of Chinese cabbages with severe clubroot in Guandu District of Kunming, Yunnan Province, China, had strong inhibitory effects on both the survival and germination of resting spores of P. brassicae. Several strategies were evaluated to efficiently manage clubroot in Chinese cabbage, and different mechanisms were investigated. The ability of Chinese cabbage root hairs to reduce infection by P. brassicae in the growth and efficiency of colonization of XF-1 on seedling roots was also studied. Responses to the suppression of clubroot increased with increased seedling age in pot and field conditions, and the rate of noninfectious root hair was enhanced by the inoculation of pathogens, suggesting that seedling age impacts the infection by P. brassicae. The application of B. subtilis XF-1 liquid culture for treatment during the developmental stages of infected Chinese cabbage seedlings gradually decreased the control effect. Moreover, soaking seeds with B. subtilis XF-1 culture reduced clubroot disease incidence rate and disease incidence by 40% and 69%, respectively. These results indicate that prevention and treatment by B. subtilis XF-1 at an early stage is the best way to reduce the damage caused by clubroot disease.

Modeling and Testing of Growth Status for Chinese Cabbage and White Radish with UAV-Based RGB Imagery

Conventional crop-monitoring methods are time-consuming and labor-intensive, necessitating new techniques to provide faster measurements and higher sampling intensity. This study reports on mathematical modeling and testing of growth status for Chinese cabbage and white radish using unmanned aerial vehicle-red, green and blue (UAV-RGB) imagery for measurement of their biophysical properties. Chinese cabbage seedlings and white radish seeds were planted at 7–10-day intervals to provide a wide range of growth rates. Remotely sensed digital imagery data were collected for test fields at approximately one-week intervals using a UAV platform equipped with an RGB digital camera flying at 2 m/s at 20 m above ground. Radiometric calibrations for the RGB band sensors were performed on every UAV flight using standard calibration panels to minimize the effect of ever-changing light conditions on the RGB images. Vegetation fractions (VFs) of crops in each region of interest from the mosaicked ortho-images were calculated as the ratio of pixels classified as crops segmented using the Otsu threshold method and a vegetation index of excess green (ExG). Plant heights (PHs) were estimated using the structure from motion (SfM) algorithm to create 3D surface models from crop canopy data. Multiple linear regression equations consisting of three predictor variables (VF, PH, and VF × PH) and four different response variables (fresh weight, leaf length, leaf width, and leaf count) provided good fits with coefficients of determination (R2) ranging from 0.66 to 0.90. The validation results using a dataset of crop growth obtained in a different year also showed strong linear relationships (R2 > 0.76) between the developed regression models and standard methods, confirming that the models make it possible to use UAV-RGB images for quantifying spatial and temporal variability in biophysical properties of Chinese cabbage and white radish over the growing season.

Short-term salt stress in Brassica rapa seedlings causes alterations in auxin metabolism

Salinity is one of major abiotic stresses affecting Brassica crop production. Here we present investigations into the physiological, biochemical, and hormonal components of the short-term salinity stress response in Chinese cabbage seedlings, with particular emphasis on the biosynthesis and metabolism of auxin indole-3-acetic acid (IAA). Upon salinity treatments (50–200 mM NaCl) IAA level was elevated in a dose dependent manner reaching 1.6-fold increase at the most severe salt treatment in comparison to the control. IAA precursor profiling suggested that salinity activated the indole-3-acetamide and indole-3-acetaldoxime biosynthetic pathways while suppressing the indole-3-pyruvic acid pathway. Levels of the IAA catabolites 2-oxoindole-3-acetic acid and indole-3-acetic acid-aspartate increased 1.7- and 2.0-fold, respectively, under the most severe treatment, in parallel with those of IAA. Conversely, levels of the ester conjugate indole-3-acetyl-1-O-ß-d-glucose and its catabolite 2-oxoindole-3-acetyl-1-O-ß-d-glucose decreased 2.5- and 7.0-fold, respectively. The concentrations of stress hormones including jasmonic acid and jasmonoyl-isoleucine (JA and JA-Ile), salicylic acid (SA) and abscisic acid (ABA) confirmed the stress induced by salt treatment: levels of JA and JA-Ile increased strongly under the mildest treatment, ABA only increased under the most severe treatment, and SA levels decreased dose-dependently. These hormonal changes were related to the observed changes in biochemical stress markers upon salt treatments: reductions in seedling fresh weight and root growth, decreased photosynthesis rate, increased levels of reactive oxygen species, and elevated proline content and the Na+/K+ ratio. Correlations among auxin profile and biochemical stress markers were discussed based on Pearson's coefficients and principal component analysis (PCA).

Pathogenic fungal protein-induced resistance and its effects on vegetable diseases

SUMMARYPlant defence systems can be induced by biotic and abiotic stress. Experiments were undertaken to explore the feasibility of different fungal proteins for the reduction of vegetable diseases. Total proteins purified from three soil-borne and five foliar fungal pathogens had no fungistatic effects nor did they trigger hypersensitive reactions on test plants. The abilities to promote plant growth and to reduce disease severity varied among test proteins and plants. Depending on test proteins, experiments have demonstrated that exogenous application of fungal proteins could reduce Alternaria brassicicola-induced black spot severity on cabbage, Colletotrichum spp.-induced anthracnose on Chinese cabbage and cucumber, Rhizoctonia solani-induced damping-off on sweet pepper and Chinese cabbage, and powdery mildew on cucumber seedlings. An Alternariaprotein effector 1 (Ape1)-coding gene was cloned from two Alternaria spp. and expressed in Escherichia coli. The expressed Ape1 reduced anthracnose incidence on cucumber leaves, indicating that Ape1 was the primary activator in the crude protein extracts responsible for disease reduction. Application of Alternaria proteins onto Chinese cabbage seedlings caused an increase of phenylalanine ammonia lyase and peroxidase activities in treated seedlings, which may have played a role in host defence.

Microwave irradiation effects on vermicasts potency, and plant growth and antioxidant activity in seedlings of Chinese cabbage (Brassica rapa subsp. pekinensis)

Vermicasts is rich in beneficial microorganisms and plant growth factors. Unlike soils, the effect of microwave irradiation (MWI) on vermicasts potency has not been reported. This study investigated MWI effects on vermicasts potency, plant growth and biochemical activity in Chinese cabbage ‘Bilko’ seedlings. Fresh, moist vermicasts were microwaved at power output levels: 0, 100, 200, 300, 400 and 800 Watts (W). Water loss, nutrients and total aerobic plate content were assessed. A complete randomized design greenhouse experiment was used to evaluate seedlings growth performance and tissue bioactivity. Water loss increased from 5 mg/g (0 W) to 215 mg/g (800 W). Total dissolved solids and electrical conductivity of the vermicasts gradually increased with an increase in MWI power output level from 0 to 200 W. This was followed by a steep rise through treatment 300 W and a peak at 400 W. Total nitrogen and nitrate decreased, while ammonia-nitrogen and nitrite-nitrogen increased at higher power levels. Similarly, phosphorus, potassium, magnesium, calcium, manganese, barium and molybdenum contents increased while sodium and barium remained fairly constant. However, MWI irradiation reduced total aerobic plate count by ≥50%. Plant growth and biomass were increased by the 400 W and 800 W MWI treatments. Antioxidant activity was highest in 200, 400 and 800 W treated plants. Collectively the finding indicated that the 400 W treatment increased the bioavailability of nutrients, and represents the best option for plant growth enhancement and improved antioxidant activity.

Appropriate NH4+: NO3\u2212 ratio improves low light tolerance of mini Chinese cabbage seedlings

BackgroundIn northwest of China, mini Chinese cabbage (Brassica pekinensis) is highly valued by consumers, and is widely cultivated during winter in solar-greenhouses where low light (LL) fluence (between 85 and 150 μmol m−2 s−1 in day) is a major abiotic stress factor limiting plant growth and crop productivity. The mechanisms with which various NH4+: NO3− ratios affected growth and photosynthesis of mini Chinese cabbage under normal (200 μmol m−2 s−1) and low (100 μmol m−2 s−1) light conditions was investigated. The four solutions with different ratios of NH4+: NO3− applied were 0:100, 10:90, 15:85 and 25:75 with the set up in a glasshouse in hydroponic culture. The most appropriate NH4+: NO3− ratio that improved the tolerance of mini Chinese cabbage seedlings to LL was found in our current study.ResultsUnder low light, the application of NH4+: NO3− (10:90) significantly stimulated growth compared to only NO3− by increasing leaf area, canopy spread, biomass accumulation, and net photosynthetic rate. The increase in net photosynthetic rate was associated with an increase in: 1) maximum and effective quantum yield of PSII; 2) activities of Calvin cycle enzymes; and 3) levels of mRNA relative expression of several genes involved in Calvin cycle. In addition, glucose, fructose, sucrose, starch and total carbohydrate, which are the products of CO2 assimilation, accumulated most in the cabbage leaves that were supplied with NH4+: NO3− (10:90) under LL condition. Low light reduced the carbohydrate: nitrogen (C: N) ratio while the application of NH4+: NO3− (10:90) alleviated the negative effect of LL on C: N ratio mainly by increasing total carbohydrate contents.ConclusionsThe application of NH4+:NO3− (10:90) increased rbcL, rbcS, FBA, FBPase and TK expression and/or activities, enhanced photosynthesis, carbohydrate accumulation and improved the tolerance of mini Chinese cabbage seedlings to LL. The results of this study would provide theoretical basis and technical guidance for mini Chinese cabbage production. In practical production, the ratio of NH4+:NO3− should be adjusted with respect to light fluence for successful growing of mini Chinese cabbage.

Potted rice straw increased the antioxidase activity and growth of Chinese green cabbage seedlings and altered the soil microbial community

ABSTRACTTo reuse rice straw and decrease the environmental pollution and resource waste that are caused by burning rice straw in China, this agricultural resource is increasingly being used to make pots with added formaldehyde and other chemicals for cultivating vegetables. A study was conducted to investigate the effects of rice straw-based pot powder on the growth and antioxidase activity of Chinese green cabbage seedlings and the soil microbial community using a molecular analysis. The results showed that there was no negative effect from the powder on cabbage growth, given that the cabbage plants that were treated with powder (1.2–3.2 g kg−1 rice straw pot powder) exhibited 1.8 to 2.5 times higher fresh biomass than the control (0 g kg−1 powder). Minor differences were found among key reactive oxygen system enzyme activities, but the superoxide dismutase activity decreased by 33–55% (1.2–3.2 g kg−1 powder). The phenylalanine ammonia-lyase activity of green Chinese cabbage that was treated with powder (1.2–3.2 g kg−1 rice straw pot powder) was 1.5 times higher than the no-powder control. The soil microbial diversity was changed, and the community composition was altered depending on the rates of powder application, according to a polymerase chain reaction-denaturing gradient gel electrophoresis analysis.

English

A fungal endophyte, Ramichloridium cerophilum , was identified as a Class 2 endophytes species obtained from the leaf of common sowthistle ( Sonchus oleraceus L). This fungus was found to grow endophylically in the roots of Chinese cabbage seedlings. Light microscopy of cross-sections of colonized Chinese cabbage roots showed that the fungus penetrates through the outer epidermal cells, grows further into the inner cortex, and colonizes the cortical tissue. Isolates of R. cerophilum 28L-9 have shown the ability to increase biomass of a nonmycorrhizal plant, Chinese cabbage. This finding is the first report of R. cerophilum could help to improve nonmycorrhizal plant. Keywords: Ramichloridium cerophilum , endophytic fungus, Chinese cabbage, plant growth promoting

Colletotrichum truncatum, a new cause of anthracnose on Chinese flowering cabbage (Brassica parachinensis) in China

Colletotrichum truncatum was for the first time found to cause severe anthracnose of Chinese flowering cabbage (Brassica parachinensis L. H. Bailey) (Cruciferae), in Guangdong province, China. Identification of this Colletotrichum species with curved conidia was based on morphological and cultural characteristics and multi-gene phylogenetic analysis, which showed that this fungus belongs to C. truncatum. Artificially inoculated seedlings of Chinese flowering cabbage showed typical symptoms of anthracnose similar to those observed in the field. To understand the cross-pathogenicity of C. truncatum isolates infecting Chinese flowering cabbage and soybean, artificial inoculations on both hosts were carried out and the results indicated that the isolates of Chinese flowering cabbage could infect soybean, and vice versa. C. truncatum was consistently re-isolated from the artificially infected tissues of both hosts. Furthermore, a comparison of the effects of environmental factors on C. truncatum isolates CBP001 and XST01 from Chinese flowering cabbage and soybean, respectively, demonstrated that these two isolates have similar biological characteristics. Therefore, it is concluded that C. truncatum is the causal agent of anthracnose of Chinese flowering cabbage.

Effect of Silicate Fertilizer on Growth, Physiology and Abiotic Stress Tolerance of Chinese Cabbage Seedlings

The objective of this study was to evaluate the effect of silicate fertilizer on growth, physiology and abiotic stress tolerance of Chinese cabbage seedlings. Five silicate concentrations (8, 16, 32, 64, and 128mM) and control (non-treatment) were applied to Chinese cabbage seedlings twice a week. Three weeks after application of silicate treatment, seedlings were used for treating abiotic stresses and were assessed for growth and physiological characteristics. Growth parameters significantly increased in 8, 16, and 32mM treatments except 64 and 128mM. Total root surface area, total root length, and number of root tips increased in 8, 16 and 32mM treatments, but they decreased in treated seedlings with 64 and 128mM of silicate. The highest growth parameters and root morphology were observed in 8mM treatment. As for the effect on the seedling physiology, transpiration rates decreased while stomatal diffusive resistance increased to increasing silicate concentration. The application of silicate reduced the electrical conductivity, heating and chilling injury index at high and low temperatures. Silicate enhanced drought tolerance of Chinese seedlings by delaying the starting time of wilting point. The starting time of wilting point in the control was 3 days after discontinuation of irrigation, while in the 8, 64 and 128mM of silicate treatments were 4 days, and the 16 and 32mM treatments were 5 days. All plants were wilted after 5 days in control without irrigation whereas it showed in 8mM treatment after 6 days, in 16, 32, 64, 128mM treatments after 7 days.

Moderate ammonium:nitrate alleviates low light intensity stress in mini Chinese cabbage seedling by regulating root architecture and photosynthesis

The hydroponic experiment was conducted to study the effects of ammonium (NH4+):nitrate (NO3−) ratios on growth, photosynthetic responses, chloroplast ultrastructure and root architecture of mini Chinese cabbage under low light intensity condition. Mini Chinese cabbage (Brassica pekinensis) seedlings were grown in pots (38cm×28cm×12cm) in a greenhouse at photosynthetic photon flux density about 200μmolm−2s−1 (normal light intensity) or 100μmolm−2s−1 (low light intensity) of light intensity. Four ammonium:nitrate ratios were applied: (a) NH4+:NO3−=0:100 (5mM NO3−), (b) NH4+:NO3−=10:90 (0.5mM NH4++4.5mM NO3−), (c) NH4+:NO3−=15:85 (0.75mM NH4++4.25mM NO3−), and (d) NH4+:NO3−=25:75 (1.25mM NH4++3.75mM NO3−). Two weeks after treatments started, under normal light, plants treated with 0.75mM NH4++4.25mM NO3− exhibited significantly promoted growth. Simultaneously, these plants showed significantly higher degree of granal stacking and photosynthesis, as well as larger absorption area of root system compared with plants fed with 5mM NO3−. Under shading condition, plants fertilized with 0.5mM NH4++4.5mM NO3− resulted in better growth and had intact chloroplast ultrastructure and a higher degree of granal stacking, chlorophyll contents and net photosynthetic rate, as well as larger root system. Our results indicate that compared with nitrate, adding moderate ammonium concentration in the nutrient could alleviate low light intensity stress in mini Chinese cabbage seedling by regulating root architecture and photosynthesis. The challenge is to determine how to manage ammonium:nitrate ratio according to the various light intensities during plant growth process.

Effects of the size and morphology of zinc oxide nanoparticles on the germination of Chinese cabbage seeds.

The toxicity of four zinc oxide nanoparticles (i.e., spheric ZnO-30, spheric ZnO-50, columnar ZnO-90, and hexagon rod-like ZnO-150) to the seed germination of Chinese cabbage (Brassica pekinensis L.) was investigated in this study. The results showed that zinc oxide nanoparticles (nano-ZnOs) did not affect germination rates at concentrations of 1-80 mg/L but significantly inhibited the root and shoot elongation of Chinese cabbage seedlings, with the roots being more sensitive. The inhibition was evident mainly during seed incubation rather than the seed soaking process. Both the production of free hydroxyl groups (·OH) and the Zn bioaccumulation in roots or shoots resulted in toxicity of nano-ZnOs to Chinese cabbage seedlings. The toxicity of nano-ZnOs was affected significantly by their primary particle sizes in the minimum dimensionality, but large columnar ZnO-90 and small spherical ZnO-50 had comparable toxicities. Therefore, both the particle size and morphology affected the toxicity of nano-ZnOs.

Pseudomonas sp. G19에 의한 배추의 염 스트레스 경감 및 생장 촉진

KACC10070 playing a role in reduction of ethylene in plant. The strain G19 increased the biomass of Chinese cabbage seedlings grown in the presence of 150 mM NaCl. The results indicated that the strain G19 promoted the growth of Chinese cabbage seedling under salinity stress through microbe-plant interactions.

Avaliação de mudas oriundas de sementes agroecológicas de couve chinesa (Brassica pekinensis) em dois tamanhos de bandeja

The use and production of agroecological seeds are promising alternatives to small farmers in organic growth system. In this context, this work aimed to verify the performance of agroecological seeds of Chinese cabbage, associated with the size of the tray, evaluating the characteristics of the seedlings: percentage of emergence, shoot height, root length, and fresh and dry weights. The experiment was conducted in a greenhouse at the Department of Agronomy of UNICENTRO in Guarapuava, Parana State. We used a 2 x 2 completely randomized factorial design, with five replicates and 16 seeds per plot. The first factor was the origin of the seeds (agroecological and conventional), and the second factor was two trays (128 and 200 cells). Seedlings from agroecological seeds showed high percentage of emergence, shoot height and fresh weight compared to conventional seeds. About the size of the tray, it was verified that the trays of 128 cells are more effective to get vigorous seedlings, due the better results in shoot height, root length and fresh weight. There was no significant interaction between seed type and size of the tray. Thus the agroecological seeds are a viable alternative for the production of Chinese cabbage seedlings.

Ozone fumigation increases the abundance of nutrients in Brassica vegetables: broccoli (Brassica oleracea var. italica) and Chinese cabbage (Brassica pekinensis).

B rassicaceae vegetables, among them broccoli and Chinese cabbage, are well recognized due to the nutritional properties. Four-week-old Chinese cabbage and broccoli seedlings were fumigated with O3 for 3 days before being transplanted into the field. The effect of O3 treatment was determined after reaching marketable quality (ca. 10 weeks). The inflorescences of O3-treated broccoli were enriched in vitamin E (α-tocopherol and γ-tocopherol), whereas Chinese cabbage heads had an increased content of anthocyanins and β-carotene. Ozone treatment did not significantly affect the productivity of both examined vegetables.

Molecular cloning and expression analysis of a Cu/Zn SOD gene (BcCSD1) from Brassica campestris ssp. chinensis

Superoxide dismutases (SODs) are a family of metalloproteins extensively exists in eukaryote, which plays an essential role in stress-tolerance of higher plants. A full-length cDNA encoding Cu/Zn SOD (BcCSD1) was isolated from young seedlings of non-heading Chinese cabbage (Brassica campestris ssp. chinensis) by rapid amplification of cDNA ends (RACE). Bioinformatics analysis revealed that BcCSD1 belonged to the plant SOD super family and had the closest relationship with SOD from Brassica napus. Tissue expression pattern analysis revealed that the BcCSD1 was constitutively expressed in all the tested tissues, and strongest in leaf, moderate in stem, lowest in root. The expression profiles under different stress treatments such as drought, NaCl, high temperature and ABA were also investigated, and the results revealed that BcCSD1 was a stress-responsive gene, especially to ABA. These results provide useful information for further understanding the role of BcCSD1 resistant to abiotic stress in Brassica campestris in the future.

Exogenous nitric oxide improves chilling tolerance of Chinese cabbage seedlings by affecting antioxidant enzymes in leaves

The effects of exogenous sodium nitroprusside (SNP), a nitric oxide (NO) donor, on growth of Chinese cabbage seedlings and antioxidant enzyme activity in leaves were studied under chilling stress. The results showed that the growth of Chinese cabbage seedlings was strongly inhibited when plants were exposed to chilling, whereas spraying SNP in shoots significantly alleviated the inhibition of growth from chilling stress. The plant height, root length, fresh and dry weight of chilling plants all increased. Chilling caused increases of membrane permeability and antioxidant enzymes activity with the exception of catalase after 8 days of treatment. Meanwhile, chilling also resulted in the decrease of chlorophyll content, accumulation of malondialdehyde (MDA) and protein in leaves. Interestingly, application SNP further enhanced the antioxidant enzyme activities, the chlorophyll and protein content, on the contrary, reduced the member permeability and MDA content. Therefore, it was concluded that NO protected plants from oxidative damage and promoted the growth by enhancing activity of antioxidant enzymes in leaves sufficiently to lower membrane injury. However, exogenous NO had no significant effects on seedling in normal conditions.

Variation of Glucosinolate Accumulation and Gene Expression of Transcription Factors at Different Stages of Chinese Cabbage Seedlings under Light and Dark Conditions

Chinese cabbage is one of the most important leafy vegetables widely used in East Asian cuisines. The glucosinolate (GSL) accumulation and transcript levels of 7 transcription factors (Dof1.1, IQD1-1, MYB28, MYB29, MYB34, MYB51, and MYB122, and their isoforms) involved in the biosynthesis of aliphatic and indolic glucosinolates (GSLs) were analyzed at different stages of Chinese cabbage (Brassica rapa ssp. pekinensis) seedlings under light and dark conditions using high performance liquid chromatography and quantitative real time PCR. During seedling development, transcription of almost all transcription factors under light conditions was higher expressed than under dark conditions. Five aliphatic GSLs (progoitrin, sinigrin, glucoalyssin, gluconapin, and glucobrassicanapin) and four indolic GSLs (4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, and neoglucobrasscin) were detected. Total GSL contents under light conditions 6, 8, and 10 days after sowing (DAS) were 3.2-, 3.9-, and 6.9-fold higher, respectively than those of dark conditions. Interestingly, total GSL contents 2 {85.4 micromol/g dry weight (DW)} to 10 (7.74 micromol/g DW) DAS under dark conditions were gradually decreased. In this study, our results suggest that light affects the levels of GSL in Chinese cabbage seedlings. These results could be useful for obtaining cabbage varieties rich in GSLs.

Proteomic analysis of non-heading Chinese cabbage infected with Hyaloperonospora parasitica

Downy mildew is a serious fungal disease in non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino) that is caused by Hyaloperonospora parasitica, which infects members of the Brassicaceae family. For breeding improvement, researchers must understand the defence mechanisms employed by non-heading Chinese cabbage to combat H. parasitica infection. Using 2-DE protein analysis, we compared the proteomes from leaves of non-heading Chinese cabbage seedlings that were infected with H. parasitica or that were only treated with water at different time points post-infection. By MS analysis, 91 protein spots with significant differences in abundance (>2-fold, p<0.05) were identified in mock- and H. parasitica-inoculated leaves. Next, a resistance strategy for incompatible interactions was proposed. This network consisted of several functional components, including enhanced ethylene biosynthesis and energy supply, balanced ROS production and scavenging, accelerated protein metabolism and photorespiratory, reduced photosynthesis, and induced photosystem repair. These findings increase our knowledge of incompatible interactions between plants and pathogens and also provide new insight regarding the function of plant molecular processes, which should assist in the discovery of new strategies for pathogen control. This study reported the proteomic analysis of the incompatible interactions between non-heading Chinese cabbage and downy mildew using 2-DE and MS. In total, 91 protein spots that were related to the resistance response were identified. These proteins were assigned to different functional categories, such as amino acid and carbohydrate metabolism, photosynthesis and photorespiration, protein metabolism, signal transduction, redox homeostasis, and ethylene biosynthesis. Meanwhile, several key proteins were determined to be associated with ethylene signalling, ROS scavenging and resistance-related proteins. Consistent with these results, the expression of ethylene biosynthesis genes and response genes, as well as the activity of antioxidant enzymes, increased after inoculation. These findings provide new insight for further understanding the molecular mechanisms of plant resistance.