Kopsell Dean A, Barickman T Casey, Sams Carl E, McElroy J Scott
Plant Sciences Department, The University of Tennessee, Knoxville 37996, USA.
J Agric Food Chem. 2007 Dec 26;55(26):10628-34. doi: 10.1021/jf072793f. Epub 2007 Dec 4.
Watercress (Nasturtium officinale R. Br.) is a perennial herb rich in the secondary metabolites of glucosinolates and carotenoids. 2-phenethyl isothiocyanate, the predominate isothiocyanate hydrolysis product in watercress, can reduce carcinogen activation through inhibition of phase I enzymes and induction of phase II enzymes. Sulfur (S) and nitrogen (N) have been shown to influence concentrations of both glucosinolates and carotenoids in a variety of vegetable crops. Our research objectives were to determine how several levels of N and S fertility interact to affect watercress plant tissue biomass production, tissue C/N ratios, concentrations of plant pigments, and glucosinolate concentrations. Watercress was grown using nutrient solution culture under a three by three factorial arrangement, with three S (8, 16, and 32 mg/L) and three N (6, 56, and 106 mg/L) fertility concentrations. Watercress shoot tissue biomass, tissue %N, and tissue C/N ratios were influenced by N but were unaffected by changes in S concentrations or by the interaction of NxS. Tissue pigment concentrations of beta-carotene, lutein, 5,6-epoxylutein, neoxanthin, zeaxanthin, and the chlorophyll pigments responded to changes in N treatment concentrations but were unaffected by S concentrations or through N x S interactions. Watercress tissue concentrations of aromatic, indole, and total glucosinolate concentrations responded to changes in N treatments; whereas aliphatic, aromatic, and total glucosinolates responded to changes in S treatment concentrations. Individual glucosinolates of glucobrassicin, 4-methoxyglucobrassicin, and gluconasturriin responded to N fertility treatments, while gluconapin, glucobrassicin, and gluconasturiin responded to changes in S fertility concentrations. Increases in carotenoid and glucosinolate concentrations through fertility management would be expected to influence the nutritional value of watercress in human diets.
西洋菜（豆瓣菜，学名Nasturtium officinale R. Br.）是一种多年生草本植物，富含次生代谢产物硫代葡萄糖苷和类胡萝卜素。2-苯乙基异硫氰酸酯是西洋菜中主要的异硫氰酸酯水解产物，它可以通过抑制I相酶和诱导II相酶来减少致癌物的活化。硫（S）和氮（N）已被证明会影响多种蔬菜作物中硫代葡萄糖苷和类胡萝卜素的含量。我们的研究目标是确定不同水平的氮和硫肥力如何相互作用，以影响西洋菜植株组织生物量的产生、组织碳氮比、植物色素浓度和硫代葡萄糖苷浓度。采用营养液培养法，按照三因素三水平的排列方式种植西洋菜，设置三个硫（8、16和32毫克/升）和三个氮（6、56和106毫克/升）肥力浓度。西洋菜地上部组织生物量、组织含氮量和组织碳氮比受氮的影响，但不受硫浓度变化或氮与硫相互作用的影响。β-胡萝卜素、叶黄素、5,6-环氧叶黄素、新黄质、玉米黄质等组织色素浓度以及叶绿素叶绿素色素叶绿素色素对氮处理浓度的变化有响应，但不受硫浓度或氮与硫相互作用的影响。西洋菜组织中芳香族、吲哚族和总硫代葡萄糖苷浓度对氮处理的变化有响应；而脂肪族、芳香族和总硫代葡萄糖苷对硫处理浓度的变化有响应。个别硫代葡萄糖苷如葡萄糖芸苔素、4-甲氧基葡萄糖芸苔素和葡萄糖芥苷对氮肥力处理有响应，而葡萄糖异硫氰酸酯、葡萄糖芸苔素和葡萄糖芥苷对硫肥力浓度的变化有响应。通过肥力管理提高类胡萝卜素和硫代葡萄糖苷浓度有望影响西洋菜在人类饮食中的营养价值。
