ABSTRACT
BACKGROUND: As the second largest leafy vegetable, cabbage (Brassica oleracea L. var. capitata) is grown globally, and the characteristics of the different varieties, forms, and colors of cabbage may differ. In this study, five analysis methods-variance analysis, correlation analysis, cluster analysis, principal component analysis, and comprehensive ranking-were used to evaluate the quality indices (soluble protein, soluble sugar, and nitrate), antioxidant content (vitamin C, polyphenols, and flavonoids), and mineral (K, Ca, Mg, Cu, Fe, Mn, and Zn) content of 159 varieties of four forms (green spherical, green oblate, purple spherical, and green cow heart) of cabbage. RESULTS: The results showed that there are significant differences among different forms and varieties of cabbage. Compared to the other three forms, the purple spherical cabbage had the highest flavonoid, K, Mg, Cu, Mn, and Zn content. A scatter plot of the principal component analysis showed that the purple spherical and green cow heart cabbage varieties were distributed to the same quadrant, indicating that their quality indices and mineral contents were highly consistent, while those of the green spherical and oblate varieties were irregularly distributed. Overall, the green spherical cabbage ranked first, followed by the green cow heart, green oblate, and purple spherical varieties. CONCLUSIONS: Our results provide a theoretical basis for the cultivation and high-quality breeding of cabbage.
Subject(s)
Antioxidants , Brassica , Antioxidants/metabolism , Brassica/genetics , Brassica/metabolism , Plant Breeding , Flavonoids/metabolism , Minerals/metabolismABSTRACT
Black rot, caused by Xanthomonas campestris pv. campestris (Xcc) significantly affects the production of cabbage and other cruciferous vegetables. Plant antioxidant system plays an important role in pathogen invasion and is one of the main mechanisms underlying resistance to biological stress. Therefore, it is important to study the resistance mechanisms of the cabbage antioxidant system during the early stages of Xcc. In this study, 108 CFU/mL (OD600 = 0.1) Xcc race1 was inoculated on "zhonggan 11" cabbage using the spraying method. The effects of Xcc infection on the antioxidant system before and after Xcc inoculation (0, 1, 3, and 5 d) were studied by physiological indexes determination, transcriptome and metabolome analyses. We concluded that early Xcc infection can destroy the balance of the active oxygen metabolism system, increase the generation of free radicals, and decrease the scavenging ability, leading to membrane lipid peroxidation, resulting in the destruction of the biofilm system and metabolic disorders. In response to Xcc infection, cabbage clears a series of reactive oxygen species (ROS) produced during Xcc infection via various antioxidant pathways. The activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) increased after Xcc infection, and the ROS scavenging rate increased. The biosynthesis of non-obligate antioxidants, such as ascorbic acid (AsA) and glutathione (GSH), is also enhanced after Xcc infection. Moreover, the alkaloid and vitamin contents increased significantly after Xcc infection. We concluded that cabbage could resist Xcc invasion by maintaining the stability of the cell membrane system and improving the biosynthesis of antioxidant substances and enzymes after infection by Xcc. Our results provide theoretical basis and data support for subsequent research on the cruciferous vegetables resistance mechanism and breeding to Xcc.
Subject(s)
Antioxidants , Brassica , Plant Diseases , Xanthomonas campestris , Xanthomonas campestris/physiology , Xanthomonas campestris/pathogenicity , Brassica/microbiology , Brassica/metabolism , Antioxidants/metabolism , Plant Diseases/microbiology , Reactive Oxygen Species/metabolismABSTRACT
BACKGROUND: BRASSINAZOLE-RESISTANT (BZR) is a class of specific transcription factor (TFs) involved in brassinosteroid (BR) signal transduction. The regulatory mechanism of target genes mediated by BZR has become one of the key research areas in plant BR signaling networks. However, the functions of the BZR gene family in cucumber have not been well characterized. RESULTS: In this study, six CsBZR gene family members were identified by analyzing the conserved domain of BES1 N in the cucumber genome. The size of CsBZR proteins ranges from 311 to 698 amino acids and are mostly located in the nucleus. Phylogenetic analysis divided CsBZR genes into three subgroups. The gene structure and conserved domain showed that the BZR genes domain in the same group was conserved. Cis-acting element analysis showed that cucumber BZR genes were mainly involved in hormone response, stress response and growth regulation. The qRT-PCR results also confirmed CsBZR response to hormones and abiotic stress. CONCLUSION: Collectively, the CsBZR gene is involved in regulating cucumber growth and development, particularly in hormone response and response to abiotic stress. These findings provide valuable information for understanding the structure and expression patterns of BZR genes.
Subject(s)
Cucumis sativus , Cucumis sativus/genetics , Genome, Plant , Phylogeny , Brassinosteroids/metabolism , Multigene Family , Hormones/metabolism , Stress, Physiological/genetics , Gene Expression Regulation, Plant , Plant Proteins/geneticsABSTRACT
Treatment of the planting and breeding waste is becoming a big issue due to their significant quantities. Composting could be an effective alternative for planting and breeding waste management which could be used as fertilizer. The purpose of this research was to evaluate the effect of planting and breeding waste on baby cabbage growth and soil properties, to establish a suitable agricultural cycle model for semi-arid area in central Gansu Province. The planting and breeding wastes [sheep manure (SM), tail vegetable (TV), cow manure (CM), mushroom residue (MR) and corn straw (CS)] were used as the raw materials in this study, which were designed 8 compost formulas for composting fermentation. With no fertilization (CK1) and local commercial organic fertilizer (CK2) as the control, the comprehensive evaluation of planting and breeding waste composts on the yield of baby cabbage, fertilizer utilization rate, soil physical and chemical properties and microbial diversity were studied to select the best compost formula suitable for the growth of baby cabbage. And the material flow and energy flow analysis of the circulation model established by the formula were carried out. The results showed that the biological yield and economic yield of baby cabbage, absorption and recycling utilization of total phosphorus (TP) and total potassium (TK) reached the maximum under the formula of SM: TV: MR: CS = 6:2:1:1. Compared with CK2, the formula of SM: TV: MR: CS = 6:2:1:1 significantly increased the richness of soil bacteria and beneficial bacteria Proteobacteria, and decreased the relative abundance of harmful bacteria Olpidiomycota. Principal component analysis showed the comprehensive score of SM: TV: MR: CS = 6:2:1:1 was the best organic compost formula suitable for producing high-quality and high-yield baby cabbage and improving soil environment. Therefore, this formula can be used as a reference organic fertilizer formula for field cultivation of baby cabbage.
Subject(s)
Brassica , Composting , Cattle , Female , Animals , Sheep , Soil/chemistry , Manure , Fertilizers , Plant Breeding , NutrientsABSTRACT
BACKGROUND: Type 2C protein phosphatase (PP2C) is a negative regulator of ABA signaling pathway, which plays important roles in stress signal transduction in plants. However, little research on the PP2C genes family of cucumber (Cucumis sativus L.), as an important economic vegetable, has been conducted. RESULTS: This study conducted a genome-wide investigation of the CsPP2C gene family. Through bioinformatics analysis, 56 CsPP2C genes were identified in cucumber. Based on phylogenetic analysis, the PP2C genes of cucumber and Arabidopsis were divided into 13 groups. Gene structure and conserved motif analysis showed that CsPP2C genes in the same group had similar gene structure and conserved domains. Collinearity analysis showed that segmental duplication events played a key role in the expansion of the cucumber PP2C genes family. In addition, the expression of CsPP2Cs under different abiotic treatments was analyzed by qRT-PCR. The results reveal that CsPP2C family genes showed different expression patterns under ABA, drought, salt, and cold treatment, and that CsPP2C3, 11-17, 23, 45, 54 and 55 responded significantly to the four stresses. By predicting the cis-elements in the promoter, we found that all CsPP2C members contained ABA response elements and drought response elements. Additionally, the expression patterns of CsPP2C genes were specific in different tissues. CONCLUSIONS: The results of this study provide a reference for the genome-wide identification of the PP2C gene family in other species and provide a basis for future studies on the function of PP2C genes in cucumber.
Subject(s)
Arabidopsis , Cucumis sativus , Arabidopsis/genetics , Arabidopsis/metabolism , Cucumis sativus/genetics , Cucumis sativus/metabolism , Gene Expression Regulation, Plant , Genes, Plant , Genome, Plant , Phylogeny , Plant Proteins/genetics , Plant Proteins/metabolism , Stress, Physiological/geneticsABSTRACT
To address the low Ca-induced growth inhibition of tomato plants, the mitigation effect of exogenous Si on tomato seedlings under low-Ca stress was investigated using different application methods. We specifically analyzed the effects of root application or foliar spraying of 1 mM Si on growth conditions, leaf photosynthetic properties, stomatal status, chlorophyll content, chlorophyll fluorescence, ATP activity and content, Calvin cycle-related enzymatic activity, and gene expression in tomato seedlings under low vs. adequate calcium conditions. We found that the low-Ca environment significantly affected (reduced) these parameters, resulting in growth limitation. Surprisingly, the application of 1 mM Si significantly increased plant height, stem diameter, and biomass accumulation, protected photosynthetic pigments, improved gas exchange, promoted ATP production, enhanced the activity of Calvin cycle key enzymes and expression of related genes, and ensured efficient photosynthesis to occur in plants under low-Ca conditions. Interestingly, when the same amount of Si was applied, the beneficial effects of Si were more pronounced under low-Ca conditions that under adequate Ca. We speculate that Si might promote the absorption and transport of calcium in plants. The effects of Si also differed depending on the application method; foliar spraying was better in alleviating photosynthetic inhibition in plants under low-Ca stress, whereas root application of Si significantly promoted root growth and development. Enhancing the photosynthetic capacity by foliar Si application is an effective strategy for ameliorating the growth inhibition of plants under low-Ca stress.
Subject(s)
Seedlings , Solanum lycopersicum , Seedlings/metabolism , Solanum lycopersicum/metabolism , Silicon/pharmacology , Silicon/metabolism , Calcium/metabolism , Photosynthesis , Chlorophyll/metabolism , Plant Leaves/metabolism , Adenosine Triphosphate/metabolismABSTRACT
In order to rapidly and precisely identify the volatile compounds in Chinese chive (Allium tuberosum Rottler), seven key parameters of headspace solid-phase micro-extraction conditions (HS-SPME) from Chinese chive were optimized. A total of 59 volatile compounds were identified by using the optimized method, including 28 ethers, 15 aldehydes, 6 alcohols, 5 ketones, 2 hydrocarbons, 1 ester, and 2 phenols. Ethers are the most abundant, especially dimethyl trisulfide (10,623.30 µg/kg). By calculating the odor activity values (OAVs), 11 volatile compounds were identified as the major aroma-active compounds of Chinese chive. From the analysis of the composition of Chinese chive aroma, the "garlic and onion" odor (OAV = 2361.09) showed an absolute predominance over the other 5 categories of aroma. The results of this study elucidated the main sources of Chinese chive aroma from a chemical point of view and provided the theoretical basis for improving the flavor quality of Chinese chive.
Subject(s)
Chive , Volatile Organic Compounds , Ethers , Gas Chromatography-Mass Spectrometry/methods , Odorants/analysis , Solid Phase Microextraction/methods , Volatile Organic Compounds/analysisABSTRACT
Cinnamic acid (CA), one of the main autotoxins secreted by cucumber roots during continuous cropping, inhibits plant growth and reduces yield. Silicon (Si) is an environmentally friendly element that alleviates abiotic stresses in plants, but the mechanism underlying its resistance to autotoxicity remain unclear. Here, we used 0.8 mmol L-1 CA to study the effects of Si application on the growth, chlorophyll fluorescence, and ascorbate-glutathione (AsA-GSH) cycle of cucumber seedlings under CA inducing conditions. Our results indicated that CA significantly induced photoinhibition and overaccumulation of reactive oxygen species (ROS), thereby inhibiting cucumber growth. Treatment with 1.0 mmol L-1 Si improved plant height, stem diameter and biomass accumulation, and protected the photosynthetic electron transport function of photosystem II in the presence of CA. Similarly, Si application maintained the ROS status by increasing ascorbate (AsA) and glutathione (GSH) production, as well as the ratios of AsA/DHA and GSH/GSSG in both leaves and roots during CA stress. In addition, Si application in CA-treated seedlings enhanced the activity of key enzymes such as ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST), and the transcription of several enzyme genes (CsAPX, CsMDHAR and CsGRï¼ from the AsA-GSH cycle. These results suggest that exogenous Si enhances CA tolerance in cucumber seedlings by protecting photosystem II activity, upregulating AsA-GSH pathway, and reducing ROS levels.
Subject(s)
Cucumis sativus , Silicon , Cinnamates , Glutathione , Photosystem II Protein Complex , Plant LeavesABSTRACT
The biological activities of the primary metabolites and secondary metabolites of 69 green cabbage varieties were tested. The LC-MS detection method was used to determine the content of 19 free amino acids (lysine, tryptophan, phenylalanine, methionine, threonine, isoleucine, leucine, valine, arginine, asparagine, glycine, proline, tyrosine, glutamine, alanine, aspartic acid, serine, and glutamate). The content of 10 polyphenols (chlorogenic acid, gallic acid, 4-coumaric acid, ferulic acid, gentisic acid, cymarin, erucic acid, benzoic acid, rutin, and kaempferol) was determined by the HPLC detection method. Considering the complexity of the data obtained, variance analysis, diversity analysis, correlation analysis, hierarchical cluster analysis (HCA), and principal component analysis (PCA) were used to process and correlate amino acid or polyphenol data, respectively. The results showed that there were significant differences between the different amino acids and polyphenols of the 69 cabbage varieties. The most abundant amino acids and polyphenols were Glu and rutin, respectively. Both amino acids and polyphenols had a high genetic diversity, and multiple groups of significant or extremely significant correlations. The 69 cabbage varieties were divided into two groups, according to 19 amino acid indexes, by PCA. Among them, seven varieties with high amino acid content all fell into the fourth quadrant. The HCA of amino acids also supports this view. Based on 10 polyphenols, the 69 cabbage varieties were divided into two groups by HCA. Based on 29 indexes of amino acids and polyphenols, 69 cabbage varieties were evaluated and ranked by PCA. Therefore, in this study, cabbage varieties were classified in accordance with the level of amino acids and polyphenols, which provided a theoretical basis for the genetic improvement of nutritional quality in cabbage.
Subject(s)
Amino Acids/analysis , Brassica/chemistry , Polyphenols/analysis , Multivariate AnalysisABSTRACT
Hydrogen sulfide (H2S), as a potential gaseous signaling molecule, is involved in mediating biotic and abiotic stress in plants. Currently, there are no studies investigating the mechanism by which H2S improves photosynthesis under black rot (BR) stress caused by Xanthomonas campestris pv. Campestris (Xcc). In this study, we investigated the effect of exogenous H2S on Xcc induced photosynthetic impairment in cabbage seedlings. BR has an inhibitory effect on the photosynthetic ability of cabbage seedlings. Xcc infection can significantly reduce the chlorophyll content, photosynthetic characteristics, chlorophyll fluorescence, Calvin cycle related enzyme activity and gene expression in cabbage leaves. The use of H2S can alleviate this inhibitory effect, reduce chlorophyll decomposition, improve gas exchange, enhance the activity of Calvin cycle related enzymes, and increase the expression of related genes. Transcriptome analysis showed that all differential genes related to photosynthesis were up regulated under H2S treatment compared to normal inoculation. Therefore, spraying exogenous H2S can improve the photosynthetic capacity of cabbage seedlings, reduce Xcc induced photoinhibition, and improve plant resistance.
Subject(s)
Brassica , Hydrogen Sulfide , Brassica/metabolism , Hydrogen Sulfide/pharmacology , Hydrogen Sulfide/metabolism , Photosynthesis , Chlorophyll/metabolism , Seedlings/metabolismABSTRACT
Hydrogen sulfide (H2S) is involved in the regulation of plant salt stress as a potential signaling molecule. This work investigated the effect of H2S on cucumber growth, photosynthesis, antioxidation, ion balance, and other salt tolerance pathways. The plant height, stem diameter, leaf area and photosynthesis of cucumber seedlings were significantly inhibited by 50 mmol·L-1 NaCl. Moreover, NaCl treatment induced superoxide anion (O2·-) and Na+ accumulation and affected the absorption of other mineral ions. On the contrary, exogenous spraying of 200 µmol·L-1 sodium hydrosulfide (NaHS) maintained the growth of cucumber seedlings, increased photosynthesis, enhanced the ascorbate-glutathione cycle (AsA-GSH), and promoted the absorption of mineral ions under salt stress. Meanwhile, NaHS upregulated SOS1, SOS2, SOS3, NHX1, and AKT1 genes to maintain Na+/K+ balance and increased the relative expression of MAPK3, MAPK4, MAPK6, and MAPK9 genes to enhance salt tolerance. These positive effects of H2S could be reversed by 150 mmol·L-1 propargylglycine (PAG, a specific inhibitor of H2S biosynthesis). These results indicated that H2S could mitigate salt damage in cucumber, mainly by improving photosynthesis, enhancing the AsA-GSH cycle, reducing the Na+/K+ ratio, and inducing the SOS pathway and MAPK pathway.
ABSTRACT
The content and proportion of sugars and acids in tomato fruit directly affect its flavor quality. Previous studies have shown that 5-aminolevulinic acid (ALA) could promote fruit ripening and improve its aroma quality. In order to explore the effect of ALA on sugar and acid quality during tomato fruit development, 0, 100, and 200 mg L-1 ALA solutions were sprayed on the fruit surface 10 days after pollination of the fourth inflorescence, and the regulation of ALA on sugar, acid metabolism and flavor quality of tomato fruit was analyzed. The results showed that ALA treatment could enhance the activities of acid invertase (AI), neutral invertase (NI), and sucrose synthase (SS), reduce the activity of sucrose phosphate synthase (SPS), up-regulate the expression of SlAI, SlNI and SlSS, change the composition and content of sugar in tomato fruit at three stages, significantly increase the content of sugars in fruit, and promote the accumulation of sugars into flesh. Secondly, ALA treatments increased the activities of phosphoenolpyruvate carboxykinase (PEPC), malic enzyme (ME), and citrate synthase (CS), up-regulated the expression of SlPPC2, SlME1, and SlCS, and reduced the citric acid content at maturity stage, thereby reducing the total organic acid content. In addition, ALA could also increase the number and mass fraction of volatile components in mature tomato fruits. These results indicated that exogenous application of ALA during tomato fruit development could promote the formation of fruit aroma quality and were also conducive to the formation of fruit sugar and acid quality.
ABSTRACT
Abscisic acid (ABA) is a very important hormone in plants. It regulates growth and development of plants and plays an important role in biotic and abiotic stresses. The Pyrabactin resistance 1-like (PYR/PYL) proteins play a central role in ABA signal transduction pathways. The working system of PYL genes in cucumber, an important economical vegetable (Cucumis sativus L.), has not been fully studied yet. Through bioinformatics, a total of 14 individual PYL genes were identified in Chinese long '9930' cucumber. Fourteen PYL genes were distributed on six chromosomes of cucumber, and their encoded proteins predicted to be distributed in cytoplasm and nucleus. Based on the phylogenetic analysis, the PYL genes of cucumber, Arabidopsis, rice, apple, Brachypodium distachyon and soybeancould be classified into three groups. Genetic structures and conserved domains analysis revealed that CsPYL genes in the same group have similar exons and conserved domains. By predicting cis-elements in the promoters, we found that all CsPYL members contained hormone and stress-related elements. Additionally, the expression patterns of CsPYL genes were specific in tissues. Finally, we further examined the expression of 14 CsPYL genes under ABA, PEG, salt stress. The qRT-PCR results showed that most PYL gene expression levels were up-regulated. Furthermore, with different treatments about 3h, the relative expression of PYL8 was up-regulated and more than 20 times higher than 0h. It indicated that this gene may play an important role in abiotic stress.
Subject(s)
Arabidopsis , Cucumis sativus , Cucumis sativus/genetics , Plant Proteins/genetics , Phylogeny , Abscisic Acid/pharmacology , Arabidopsis/genetics , Hormones/metabolismABSTRACT
The ALAD gene encodes an enzyme that is essential for chlorophyll biosynthesis and is involved in many other physiological processes in plants. In this study, the CaALAD gene was cloned from pepper and sequenced. Multiple sequence alignment and phylogenetic analysis of ALAD proteins from nine plant species showed that ALAD is highly conserved, and that CaALAD shows the highest homology with the ALAD protein from eggplant. Subcellular localization indicated that the CaALAD protein is mainly localized to the chloroplasts. After transferring CaALAD into the Arabidopsis thaliana genome, cold tolerance of the transgenic lines improved. Overexpression of CaALAD increased the relative transcription of the AtCBF2, AtICE1, and AtCOR15b genes in transgenic Arabidopsis plants exposed to low temperature (4°C) stress, and the contents of reactive oxygen species decreased due to increased activities of superoxide dismutase, peroxidase, and catalase. Moreover, chlorophyll biosynthesis, as determined by the contents of porphobilinogen, protoporphyrin IX, Mg-protoporphyrin IX, prochlorophyllate, and chlorophyll in the transgenic Arabidopsis plants, increased in response to low temperature stress. In addition, the transgenic lines were more sensitive to exogenous ALA and NaHS, and the H2S content of transgenic line plants increased more rapidly than in the wild-type, suggesting that CaALAD may respond to low temperatures by influencing the content of H2S, a signaling molecule. Our study gives a preliminary indication of the function of CaALAD and will provide a theoretical basis for future molecular breeding of cold tolerance in pepper.
ABSTRACT
The sucrose non-fermenting-1-related protein kinase 2 (SnRK2) is a plant-specific type of serine/threonine protein kinase that plays an important role in the physiological regulation of stress. The objective of this study was to identify and analyze the members of the SnRK2 gene family in cucumber and lay a foundation for further exploration of the mechanism of CsSnRK2 resistance to stress. Here, 12 SnRK2 genes were isolated from cucumber and distributed on five chromosomes, phylogenetic clustering divided these into three well-supported clades. In addition, collinearity analysis showed that the CsSnRK2 gene family underwent purifying selection pressure during evolution. CsSnRK2 genes of the same group have similar exons and conserved motifs, and intron length may be a specific imprint for the evolutionary amplification of the CsSnRK2 gene family. By predicting cis elements in the promoter, we found that the promoter region of CsSnRK2 gene members had various cis-regulatory elements in response to hormones and stress. Relative expression analysis showed that CsSnRK2.11 (group II) and CsSnRK2.12 (group III) were strongly induced by ABA, NaCl and PEG stress; whereas CsSnRK2.2 (group III) was not activated by any treatment. The response of group I CsSnRK2 to ABA, NaCl and PEG was weak. Furthermore, protein interaction prediction showed that multiple CsSnRK2 proteins interacted with four proteins including protein phosphatase 2C (PP2C), and it is speculated that the CsSnRK2 genes may also an independent role as a third messenger in the ABA signaling pathway. This study provides a reference for analyzing the potential function of CsSnRK2 genes in the future research.
Subject(s)
Cucumis sativus , Cucumis sativus/genetics , Plant Proteins/genetics , Phylogeny , Sodium Chloride , Protein Serine-Threonine Kinases/geneticsABSTRACT
Autotoxicity is a key factor that leads to obstacles in continuous cropping systems. Although Si is known to improve plant resistance to biotic and abiotic stresses, little is known about its role in regulating leaf water status, mineral nutrients, nitrogen metabolism, and root morphology of cucumber under autotoxicity stress. Here, we used cucumber seeds (Cucumis sativus L. cv. "Xinchun No. 4") to evaluate how exogenous Si (1 mmol L-1) affected the leaf water status, mineral nutrient uptake, N metabolism-related enzyme activities, root morphology, and shoot growth of cucumber seedlings under 0.8 mmol L-1 CA-induced autotoxicity stress. We found that CA-induced autotoxicity significantly reduced the relative water content and water potential of leaves and increase their cell sap concentration. CA-induced stress also inhibited the absorption of major (N, P, K, Ca, Mg) and trace elements (Fe, Mn, Zn). However, exogenous Si significantly improved the leaf water status (relative water content and water potential) of cucumber leaves under CA-induced stress. Exogenous Si also promoted the absorption of mineral elements by seedlings under CA-induced stress and alleviated the CA-induced inhibition of N metabolism-related enzyme activities (including nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase, glutamate dehydrogenase). Moreover, exogenous Si improved N uptake and utilization, promoted root morphogenesis, and increased the growth indexes of cucumber seedlings under CA-induced stress. Our findings have far-reaching implications for overcoming the obstacles to continuous cropping in cucumber cultivation.
ABSTRACT
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.
Subject(s)
Brassica/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Sulfur/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Amino Acid Motifs , Brassica/growth & development , Brassica/metabolism , Chromosome Mapping , Chromosomes, Plant , Conserved Sequence , Genes, Plant , Genome, Plant , Multigene Family , Photosynthesis , Plant Growth Regulators/metabolism , Promoter Regions, Genetic , Stress, PhysiologicalABSTRACT
As one of the important sources of human nutrition, Brassicaceae vegetables are widely grown worldwide. Black rot caused by Xanthomonas campestris pv. campestris (Xcc) seriously affects the quality and yield of Brassicaceae vegetables. Therefore, it is important to study control methods of Xcc for Brassicaceae vegetable production. This paper reviews the physical, chemical, and biological control methods of Xcc in Brassicaceae vegetables developed in recent years, and the underlying mechanisms of control methods are also discussed. Based on our current knowledge, future research directions for Xcc control are also proposed. This review also provides a reference basis for the control of Xcc in the field cultivation of Brassicaceae vegetables.
ABSTRACT
This study investigated the effects of exogenous 2, 4-epibrassinolide lactone (EBR) on the growth, photosynthetic pigments, antioxidant defense system, ion homeostasis, MAPK cascade and key genes of SOS signaling pathway of cucumber seedlings under salt stress using cucumber "Xinchun 4" as the test material. The experiment was set up with four treatments: foliar spraying of distilled water (CK), 50 mmol.L-1 NaCl (NaCl), 50 mmol.L-1 NaCl+foliar spray of 0.02 µmol.L-1 EBR (EBR+NaCl), and 50 mmol.L-1 NaCl+foliar spray of 24 µmol.L-1 Brassinazole (BRZ) (BRZ+NaCl). The results showed that EBR+NaCl treatment significantly increased plant height, above-ground fresh weight, total root length, total root surface area, average rhizome and photosynthetic pigment content compared to NaCl treatment. Meanwhile, compared with NaCl treatment, EBR+NaCl treatment significantly increased superoxide dismutase, catalase and ascorbate peroxidase (SOD, CAT and APX) activities, significantly promoted the accumulation of osmoregulatory substances (soluble sugars and proline), and thus effectively reduced malondialdehyde (MDA) content and relative electrical conductivity of cucumber leaves. Exogenous spraying of EBR also significantly reduced Na+/K+ under NaCl stress, effectively alleviating the toxic effects of Na+ ions. In addition, exogenous EBR induced the up-regulated expression of CsMAPK3, CsMAPK4, CsMAPK6 and CsMAPK9 genes in the MAPK cascade signaling pathway and CsSOS1, CsSOS2 and CsSOS3 genes in the SOS signaling pathway to enhance salt tolerance in cucumber under NaCl stress. Therefore, exogenous spraying EBR may effectively reduce the damage of salt stress on cucumber seedlings by improving antioxidant capacity, maintaining ion homeostasis and activating salt-tolerant related signaling pathways, which might promote the growth of cucumber seedlings and the establishment of root system morphology. This study provides a reference for EBR to improve the salt tolerance of cucumber.
ABSTRACT
Melatonin plays key roles in improving fruit quality and yield by regulating various aspects of plant growth. However, the effects of how melatonin regulates primary and secondary metabolites during fruit growth and development are poorly understood. In this study, the surfaces of tomato fruit were sprayed with different concentrations of melatonin (0, 50, and 100 µmol·L-1) on the 20th day after anthesis; we used high-performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometry (LC/MS) to determine the changes in primary and secondary metabolite contents during fruit development and measured the activity of sucrose metabolizing enzymes during fruit development. Our results showed that 100 µmol·L-1 melatonin significantly promoted the accumulation of soluble sugar in tomato fruit by increasing the activities of sucrose synthase (SS), sucrose phosphate synthase (SPS), and acid convertase (AI). The application of 100 µmol·L-1 melatonin also increased the contents of ten amino acids in tomato fruit as well as decreased the contents of organic acids. In addition, 100 µmol·L-1 melatonin application also increased the accumulation of some secondary metabolites, such as six phenolic acids, three flavonoids, and volatile substances (including alcohols, aldehydes, and ketones). In conclusion, melatonin application improves the internal nutritional and flavor quality of tomato fruit by regulating the accumulation of primary and secondary metabolites during tomato fruit ripening. In the future, we need to further understand the molecular mechanism of melatonin in tomato fruit to lay a solid foundation for quality improvement breeding.