UV-B irradiation enhances the accumulation of beneficial glucosinolates induced by melatonin in Chinese kale sprout

Cruciferous sprout is a new form of vegetable product rich in bioactive compounds,especially glucosinolates.Previous studies have focused on increasing the accumulation of glucosinolates in cruciferous sprouts by applying different chemical regulators,with a particular focus on their contribution to nutritional quality and health benefits.Nevertheless,the effects of melatonin and UV-B irradiation on glucosinolate biosynthesis remain unclear.In this study,it was found that changes in melatonin concentrations significantly affected the contents of individual as well as total aliphatic and indolic glucosinolates.The 5μmol·L^(-1)melatonin was decided as the optimum concentration that could increase the content of beneficial glucosinolates including glucoraphanin and 4-methoxy glucobrassicin in Chinese kale sprouts.Notably,the enhancement of glucosinolate accumulation by melatonin treatment could be further amplified by UV-B irradiation.Furthermore,our results showed that R2R3-MYB transcription factor BoaMYB28 and BoaMYB51,which are central regulators of aliphatic and indolic glucosinolate biosynthesis respectively,were both involved in the regulation of glucosinolate biosynthesis by melatonin and UV-B irradiation.Additionally,the expression of glucosinolate biosynthetic genes,including BoaCYP79F1,BoaCYP83A1,BoaSUR1,BoaUGT74B1,BoaCYP79B2,BoaCYP79B3,and BoaCYP83B1 participated in the formation of core structures and BoaFMOGS-OX5,BoaAOP2,BoaCYP81F2,and BoaIGMT1 involved in the sidechain modification of aliphatic and indolic glucosinolate,was regulated by melatonin or UV-B irradiation.Taken together,these findings provide a potential strategy for improving the nutritional quality and resistance of Chinese kale sprouts.

Effects of fresh-cut and storage on glucosinolates profile using broccoli as a case study

Glucosinolates(GLS) contribute to the unique flavour, nutrition, and plant defence of the Cruciferous vegetables. Understanding the GLS changes through postharvest processing is essential for defined preservation. In this study, four different fresh-cut types, whole flower(W),floret(F), quarterly cut floret(QF) and shredded floret(FS) of broccoli, were stored for 0, 1, 2 and 3 day(s) to explore GLS responses to postharvest treatments. As a result, seven GLS were identified, mainly including glucoraphanin(RAA), neoglucobrassicin(NEO), and glucobrassicin(GBC)and accounting for 52.69%, 20.12% and 14.99% of the total GLS(21.92 ± 0.48) μmol · g ^(-1 )DW, respectively. FS had the sharpest decrease in GLS after three days of storage(6.55 ± 0.37) μmol · g-1DW, while QF had the least(10.16 ± 0.33) μmol · g ^(-1 )DW. All GLS components decreased over storage, except for 4-methoxyglucobrassicin(4 ME) in FS and QF, suggesting its key role in serious wound defence. The results suggested certain postharvest approaches influenced the flavour and nutrition of broccoli.

Diversity of glucosinolates among common Brassicaceae vegetables in China

Brassicaceae vegetables are an important traditional daily food in China and around the world, which provide nutrients and phytochemicals that are beneficial for human health. Among them, Brassica and Raphanus are widely cultivated and eaten, have been evolved and/or bred for special characteristics during the long history of cultivation. Epidemiological studies suggest that the health benefits of Brassicaceae vegetables are mainly associated with glucosinolates(GSLs) and their hydrolytic products. In this review, we discuss the diversity of common consumed Brassicaceae vegetables and their GSL composition in edible parts. We also discuss the diversity factors affecting GSL content, and the diversity roles and functions of GSL. The information in this review provides guidance for consumers to select vegetables with a high GSL content,optimum edible stages, suitable edible methods, and provides a theoretical basis for crop molecular breeding and market development of GSL products.

Glucosinolates and Their Hydrolysis Products in Arabidopsis thaliana Influence Performance and Feeding Choice of Pieris rapae and Spodoptera exigua

Glucosinolates and their hydrolysis products, found in plants of the order Brassicales, are well-known for their defensive properties against insect herbivores. Arabidopsis thaliana (Col-0) genetic lines with mutations that modify the type of glucosinolates (i.e. myb28myb29 and cyp79B2cyp79B3 are deficient in the production of aliphatic and indolyl glucosinolates, respectively) make it possible to test for the specific effects of these secondary chemicals on insect herbivores. The Pad3 mutant (deficient in camalexin), which has a role in resistance to pathogens, was also tested. Likewise, the effects of different glucosinolate hydrolysis products can be evaluated using genetically modified (GM) lines of the wild type Col-0 ecotype, which naturally produces isothiocyanates. These GM lines include the nitrile-producing 35S: ESP and the double knockout tgg1tgg2, which virtually lacks hydrolysis products. In both no-choice and choice experiments, the crucifer specialist Pieris rapae was virtually unaffected by differences in the type of glucosinolates or hydrolysis products. In contrast, the generalist insect Spodoptera exigua had statistically significant increases in pupae/adult weight and faster developmental times when reared on mutants deficient in the production of aliphatic and indolyl glucosinolates and their hydrolysis products. There were no differences in the performance of either insect species when reared on wild type Col-0 or Pad3. Results from feeding choice trials showed that Pieris rapae had no statistically significant preference for any of the genetic lines. In contrast, Spodoptera exigua had a significant feeding preference for the double mutant tgg1tgg2. This study provides evidence that variation in the type of glucosinolates and their hydrolysis products can influence insect performance and feeding choices, and that responses are species-specific.

壳寡糖对羽衣甘蓝芽苗硫代葡萄糖苷及抗氧化活性的影响

为探究壳寡糖(COS)对羽衣甘蓝芽苗生长的影响,为芽苗生产上壳寡糖的合理施用提供参考,以京羽一号为试验材料,在种子发芽后施用不同质量浓度COS(25,50,75,100 mg/L)溶液,观察壳寡糖对羽衣甘蓝芽苗生长指标、硫代葡萄糖苷(简称硫苷)含量及抗氧化能力的影响。结果表明,施用75 mg/L COS处理的羽衣甘蓝芽苗总酚、总黄酮、总硫苷质量以及黑芥子酶活性和DPPH自由基清除率呈现上升趋势,且与对照差异显著,较对照分别增加25.99%,17.99%,29.68%,141.88%和2.51%;100 mg/L COS处理的羽衣甘蓝芽苗的产量及总酚、总黄酮、钠和硼含量及黑芥子酶活性也得到了相应提升,且与对照差异显著,较对照分别增加了15.21%,21.29%,22.47%,15.97%,32.63%,97.71%。经相关性分析,可以得出芽苗的产量与类胡萝卜素、总酚、总黄酮含量及DPPH自由基清除率均呈显著正相关关系。综上可得,经壳寡糖处理后可提高羽衣甘蓝芽苗的产量,提升芽苗的营养品质和抗氧化能力,增加芽苗的食用价值。

水杨酸处理对采后西兰花褪绿转黄及营养品质的影响

本实验探讨了水杨酸(salicylic acid,SA)处理对贮藏期间西兰花色泽以及营养品质的保护作用。结果表明,SA处理明显推迟了西兰花褪绿转黄进程,处理样本表现出较高的叶绿素含量、-a^(*)/b^(*)值、量子产量和荧光下降比,以及较低的L^(*)值和黄化指数。同时,与对照组相比,处理样品萝卜硫苷、芸薹葡糖硫苷、萝卜硫素、吲哚-3-甲醇及抗坏血酸(ascorbic acid,AsA)的损失显著受到抑制,总酚和总黄酮含量的积累明显增加;此外,处理组样本抗氧化能力明显提高,丙二醛含量显著降低。多变量统计分析直观地展示了感官变量及营养变量在两组样本中的分布,进一步证明SA处理对萝卜硫苷和AsA的保护作用更强,且可有效诱导抗氧化能力的提高。

不同处理对油菜秸秆养分、纤维结构和硫苷含量的影响

【目的】采用物理(膨化)和微生物(黑曲霉、枯草芽孢杆菌)处理油菜秸秆,并分析发酵后的营养物质含量、纤维结构和硫代葡萄糖苷含量,旨在提高油菜秸秆作为粗饲料在反刍动物上的饲用价值。【方法】试验设计6个组,分别为:油菜秸秆(M组,即对照组)、对照加黑曲霉(MA组)、对照加枯草芽孢杆菌(MB组)、对照膨化(PM组)、对照膨化加黑曲霉(PMA组)、对照膨化加枯草芽孢杆菌(PMB组)。【结果】与M组(2.60%)相比,其他各组的粗蛋白质含量显著增加(P<0.05),分别为3.16%(MA组)、3.24%(MB组)、3.31%(PM组)、4.02%(PMA组)、3.73%(PMB组);与M组(83.4%)相比,其他各组的中性洗涤纤维(NDF)含量显著降低(P<0.05),分别为81.6%(MA组)、80.3%(MB组)、80.4%(PM组)、77.3%(PMA组)、78.3%(PMB组)。MA组的结晶度(27.0%vs 25.3%)和比表面积(1.22 m2/g vs 1.19 m2/g)显著高于M组(P<0.05),氢键作用力减弱,聚合度与其他各组无显著差异(P>0.05);与M组(0.49μmol/g)相比,其他各组硫代葡萄糖苷含量显著降低(P<0.05),PMA组(0.24μmol/g)和PMB组(0.22μmol/g)样品的硫代葡萄糖苷含量差异不显著,但显著低于其他各组(P<0.05)。【结论】通过物理和微生物处理油菜秸秆能通过破坏纤维结构降低NDF水平,并减少抗营养因子硫代葡萄糖苷含量,从而改善其在反刍动物上的饲用价值。

The effect of glutathione on glucosinolate biosynthesis through the sulfur assimilation pathway in pakchoi associated with the growth conditions

Glucosinolates(GSLs) are a group of nitrogen-and sulfur-containing secondary metabolites, synthesized primarily in members of the Brassicaceae family, that play an important role in food flavor, plant antimicrobial activity, resistance to insect attack, stress tolerance, and human anti-cancer effects. As a sulfur-containing compound, glutathione has a strong connection with GSLs biosynthesis as a sulfur donor or redox system, and exists in reduced(glutathione;GSH) and oxidized(glutathione disulfide;GSSG) forms. However, the mechanism of GSH regulating GSLs biosynthesis remainds unclear. Hence, the exogenous therapy to pakchoi under normal growth condition and sulfur deficiency condition were conducted in this work to explore the relevant mechanism. The results showed that exogenous application of buthionine sulfoximine, an inhibitor of GSH synthesis, decreased the transcript levels of GSLs synthesis-related genes and transcription factors, as well as sulfur assimilation-related genes under the normal growth condition. Application of exogenous GSH inhibited the expression of GSLs synthesis-and sulfur assimilation-related genes under the normal condition, while the GSLs biosynthesis and the sulfur assimilation pathway were activated by exogenous application of GSH when the content of GSH in vivo of plants decreased owing to sulfur deficiency. Moreover,exogenous application of GSSG increased the transcript levels of GSLs synthesis-and sulfur assimilation-related genes under the normal growth condition and under sulfur deficiency. The present work provides new insights into the molecular mechanisms of GSLs biosynthesis underlying glutathione regulation.

Transcriptomics integrated with metabolomics reveals the mechanism of CaCl_(2)-HCl electrolyzed water-induced glucosinolate biosynthesis in broccoli sprouts

Glucosinolates are important phytochemicals in Brassicaceae.We investigated the effect of CaCl_(2)-HCl electrolyzed water(CHEW)on glucosinolates biosynthesis in broccoli sprouts.The results showed that CHEW treatment significantly decreased reactive oxygen species(ROS)and malondialdeh yde(MDA)contents in broccoli sprouts.On the the 8^(th)day,compared to tap water treatment,the the total glucosinolate content of broccoli sprouts with CHEW treatment increased by 10.6%and calcium content was dramatically enhanced from 14.4 mg/g DW to 22.7 mg/g DW.Comparative transcriptome and metabolome analyses revealed that CHEW treatment activated ROS and calcium signaling transduction pathways in broccoli sprouts and they interacted through MAPK cascades.Besides,CHEW treatment not only promoted the biosynthesis of amino acids,but also enhanced the expression of structural genes in glucosinolate synthesis through transcription factors(MYBs,bHLHs,WRKYs,etc.).The results of this study provided new insights into the regulatory network of glucosinolates biosynthesis in broccoli sprouts under CHEW treatment.

Physiological and transcriptome analyses of Chinese cabbage in response to drought stress

Chinese cabbage is an important leafy vegetable crop with high water demand and susceptibility to drought stress.To explore the molecular mechanisms underlying the response to drought,we performed a transcriptome analysis of drought-tolerant and-sensitive Chinese cabbage genotypes under drought stress,and uncovered core drought-responsive genes and key signaling pathways.A co-expression network was constructed by a weighted gene coexpression network analysis(WGCNA)and candidate hub genes involved in drought tolerance were identified.Furthermore,abscisic acid(ABA)biosynthesis and signaling pathways and their drought responses in Chinese cabbage leaves were systemically explored.We also found that drought treatment increased the antioxidant enzyme activities and glucosinolate contents significantly.These results substantially enhance our understanding of the molecular mechanisms underlying drought responses in Chinese cabbage.

浙江省地方芥菜种质资源苦味评价与优异种质筛选

浙江省芥菜种质资源丰富,芥菜产业发达,其中榨菜和雪菜的加工产品享有盛名,相比之下,浙江鲜食芥菜产业还有待发展。鲜食芥菜栽培管理不当极易出现苦味加重的现象,极大地限制了浙江省鲜食芥菜产业的发展。以浙江省芥菜种质资源为材料,对芥菜的不同部位(叶片、叶柄、嫩叶、老叶)及不同季节(秋冬季、夏季)的芥菜进行苦味评价,结果发现软叶比叶柄苦、嫩叶比老叶苦、夏季芥菜比冬季芥菜苦。分析芥子油苷的数据,发现软叶中的总芥子油苷含量高于叶柄、嫩叶中的总芥子油苷含量高于老叶、夏季芥菜的总芥子油苷含量高于冬季芥菜,即总芥子油苷含量与苦味的变化趋势一致。通过以上研究最终筛选出5份苦味适中芥菜种质,为浙江省鲜食芥菜产业的发展奠定基础。

外源谷胱甘肽对青花菜硫代葡萄糖苷合成的影响

为探究谷胱甘肽对硫代葡萄糖苷(GSLs)生物合成的影响,以现蕾期青花菜品种耐寒优秀为试验材料,研究不同浓度的还原型谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)及丁硫堇(BSO)对青花菜花球中硫代葡萄糖苷及其相关底物含量、酶活性和基因表达的影响。结果表明,与CK(蒸馏水)相比,5 mg·L^(-1) GSH在处理48 h显著提高了青花菜花球中总硫苷、脂肪族硫苷含量,在24~48 h显著提高半胱氨酸(Cys)含量,在6~24 h显著提高了谷胱甘肽含量,在3~12 h显著提高了硫苷合成相关基因的表达量;45 mg·L^(-1) GSH处理在48 h显著降低了青花菜花球中总硫苷、脂肪族硫苷含量,在3~48 h则显著提高了半胱氨酸含量,在6~48 h则显著提高了谷胱甘肽含量,在3~12 h显著抑制了硫苷合成相关基因的表达。与CK相比,5 mg·L^(-1) GSSG处理下青花菜花球中总硫苷、脂肪族硫苷含量显著升高,而25、45及65 mg·L^(-1) GSSG处理则对总硫苷、脂肪族硫苷含量没有产生显著影响。综上所述,外源谷胱甘肽对硫苷含量的影响具有浓度效应,5 mg·L^(-1) GSH促进硫苷合成,45 mg·L^(-1) GSH抑制硫苷合成。

甘蓝型油菜种子硫苷含量全基因组关联分析

【目的】挖掘与种子硫苷含量显著关联的SNP位点及候选基因,有助于油菜品质改良和培育高品质油菜品种。【方法】以300份甘蓝型油菜自交系为材料,考察了江西农业大学试验地和江西省红壤及种质资源研究所试验地2种环境下种子硫苷含量,采用前期开发的201817个SNP(singlenucleotidepolymorphism,SNP)标记对油菜种子硫苷含量进行全基因组关联分析(genome-wide association study,GWAS),搜寻显著位点两侧100 kb范围内的候选基因并进行功能注释。【结果】300份甘蓝型油菜种子硫苷含量在两地均表现出表型差异;基于一般线性模型和混合线性模型检测到209个硫苷含量显著关联SNP位点,其中两地两种方法重复检测到41个SNP位点,分别在A05(1个)、A09(36个)、C09(4个)3条染色体上。候选基因功能注释结果显示,有8个候选基因参与硫苷生物合成途径(GO:0019761),包含调控硫苷合成相关基因MYB28(BnaC09g05290D、BnaC09g05300D)、MYB34(BnaA09g05480D)和编码硫苷转运蛋白2相关基因(BnaA09g06180D、BnaA09g06190D)。【结论】通过两种方法在两地检测到多个与硫苷显著关联的SNP位点,并在显著性位点附近挖掘到相关候选基因,研究结果有助于解析甘蓝型油菜硫苷含量的遗传变异,为低硫苷含量油菜新品种的遗传改良提供基础。

植物中硫代葡萄糖苷的影响因素及研究现状

硫代葡萄糖苷是主要存在于十字花科植物中的一类重要次生代谢物,其降解产物具有较高的生物活性,对宫颈癌、乳腺癌等多种癌症有显著抑制功效,且安全性较高,深受消费者关注。本文对影响植物中硫苷种类、含量的因素进行了综述,以期为该类物质的深度开发提供参考。

芫根中硫代葡萄糖苷的提取工艺研究

本试验以高原特色作物芫根为研究对象,乙醇为浸提剂,提取芫根中的硫代葡萄糖苷。利用单因素试验研究不同提取时间、提取温度、乙醇浓度以及料液比对硫代葡萄糖苷提取量的影响,再通过正交试验设计优化提取工艺条件。结果表明,乙醇浸提法提取芫根中硫代葡萄糖苷的最佳工艺条件为:提取时间30 min,提取温度90℃,乙醇浓度70%,料液比1:20,在此条件下芫根总硫代葡萄糖苷的平均提取量达到34.58μmol/g。本研究不仅为芫根的高价值利用提供了新的思路,同时为天然硫代葡萄糖苷的高效率提取和定量分析提供了理论参考。

Solid state fermentation of rapeseed cake with Aspergillus niger for degrading glucosinolates and upgrading nutritional value

Background： Rapeseed cake is a good source of protein for animal feed but its utilization is limited due to the presence of anti-nutritional substances, such as glucosinolates （GIs）, phytic acid, tannins etc. In the present study, a solid state fermentation （SSF） using Aspergillus niger was carried out with the purpose of degrading glucosinolates and improving the nutritional quality of rapeseed cake （RSC）. The effects of medium composition and incubation conditions on the GIs content in fermented rapeseed cake （FRSC） were investigated, and chemical composition and amino acid in vitro digestibility of RSC substrate fermented under optimal conditions were determined. Results： After 72 h of incubation at 34℃, a 76.89% decrease in GIs of RSC was obtained in solid medium containing 70% RSC, 30% wheat bran at optimal moisture content 60% （w/w）. Compared to unfermented RSC, trichloroacetic acid soluble protein （TCA-SP）, crude protein and ether extract contents of the FRSC were increased （P〈 0.05） 103.71, 23.02 and 23.54%, respectively. As expected, the contents of NDF and phytic acid declined （P〈 0.05） by 9.12 and 44.60%, respectively. Total amino acids （TAA） and essential amino acids （EAA） contents as well as AA in vitro digestibility of FRSC were improved significantly （P 〈 0.05）. Moreover, the enzyme activity of endoglucanase, xylanase, acid protease and phytase were increased （P 〈 0.05） during SSF. Conclusions： Our results indicate that the solid state fermentation offers an effective approach to improving the quality of proteins sources such as rapeseed cake.

Effect of Nitrogen and Sulfur Supply on Glucosinolates in Brassica campestris ssp.chinensis

Glucosinolates （GSs） are a group of plant secondary metabolites containing abundant nitrogen （N） and sulfur （S） mainly in Brassica and have the beneficial effects on human health including anti-carcinogenic, cholesterol-reducing and other pharmacological effects. The objective of this study was to investigate the effect of different concentrations of N （5, 10, and 20 mmol L-a, denoted by N5, N10 and N20） and S （0,5, 1, and 2 mmol L^-1, denoted by S0.5, S1 and S2） on the yield and GSs in pakchoi （Brassica campestris L. ssp. chinensis var. communis） in hydroponics. Results showed that N10 and N20 significantly enhanced the yield compared with N5, however, N20 had a negative effect relative to N10. Only with N10 and N20 low S supply （S0.5） reduced the yield. The concentrations of aliphatic GSs, aromatic GS and total GSs were enhanced by N5 and indolyl GSs were enhanced by N20. S2 enhanced the concentration of individual GS and total GSs. The concentrations of indolyl GSs were maximized in N20S2 treatment, whereas the highest concentrations of aliphatic GSs, aromatic GS and total GSs were found in N5S2 treatment. Effects of N and S on aliphatic GSs were higher than on indolyl GSs. The results suggest that the accumulation of aliphatic GSs and aromatic GS could be enhanced by low N and high S and restricted by high N while that of indolyl GSs could be enhanced by high N and high S.

Identification of MAM1s in Regulation of 3C Glucosinolates Accumulation in Allopolyploid Brassica juncea

Allopolyploid Brassica juncea is particularly enriched in sinigrin,a kind of 3C aliphatic glucosinolates(GSLs),giving rise to characteristic taste after picking.However,the molecular mechanism underlying 3C aliphatic GSLs biosynthesis in this species remains unknown.In this study,we genome-widely identified GSLs metabolic genes,indicating different evolutionary rate of GSLs metabolic genes between subgenomes of B.juncea.Eight methythioalkylmalate synthase(MAMs)homologs were identified from B.juncea,in which six MAM1s were located in chloroplast and the other two were not detected with any expression.Furthermore,BjMAM1-4,BjMAM1-5,and BjMAM1-6 displayed higher expression levels in leaves than other tissues.Silenced expression analysis revealed that BjMAM1-4 and BjMAM1-6 function in 3C and 4C aliphatic GSLs accumulation.The specificity of the substrate selection for the second cycle reaction is much lower than that of the first cycle,suggesting these genes may preferentially catalyze 3C aliphatic GSLs biosynthesis.Our study provides insights into the molecular mechanism underlying the accumulation of 3C aliphatic GSLs,thereby facilitating the manipulation of aliphatic GSLs content in B.juncea.

Degradation of glucosinolates in rapeseed meal by Lactobacillus delbrueckii and Bacillus subtilis

Lactobacillus delbrueckii and Bacillus subtilis were employed as a new combination of strains to treat rapeseed meal by solid-state fermentation,aiming to efficiently degrade the glucosinolates,which are the main toxin in the meal.Single-factor tests and Response surface methodology(RSM)were used to optimize the fermentation parameters.Under the optimum fermentation parameters of 15%total injection volume of the mixture of Lactobacillus delbrueckii and Bacillus subtilis with a ratio of 2:1,bran content of16%,feed to water ratio of 1:1.5,fermentation temperature of 36°C and fermentation time of 72 h,the content of glucosinolates in rapeseed meal was decreased from 64.558μmol/g to 3.473μmol/g,reaching a high degradation rate(94.62%).The high detoxification rate by a consortium of Lactobacillus delbrueckii and Bacillus subtilis provides a bright application prospect in feed utilization of rapeseed meal.

Glucosinolates and Sinapine in Camelina Meal

Forty seven accessions of camelina (Camelina sativa L. Crantz) were analyzed for glucosinolates (GSLs) and sinapine in defatted meal. These antinutritional compounds are undesirable in camelina meal for use in animal feeding and therefore we show their variability to identify the best varieties for future breeding programs. Total GSLs ranged from 19.6 to 40.3 mmol Kg-1 dry weight (DW) with an average of 30.3 mmol kg-1 DW. Great variability has also been observed in the levels of individual GSLs (GSL1, GSL2 and GSL3), so that the content of GSL1 and GSL3 were not correlated to each other in the accessions of camelina. Five out of six winter forms of camelina showed low content of GSLs. Sinapine ranged from 1.09 to 4.75 g Kg-1 DW with an average of 2.57 g kg-1 DW. The sinapine content was not correlated with that of GSLs. The use of camelina meal is only limited by the presence of GSLs while sinapine content can be ignored in camelina varieties.