Hall Matthew K D, Jobling Jenny J, Rogers Gordon S
Faculty of Agriculture and Environment, The University of Sydney, Eveleigh, 2015, Australia.
J Sci Food Agric. 2015 Feb;95(3):552-9. doi: 10.1002/jsfa.6774. Epub 2014 Jul 8.
Changes in the concentration of the three most abundant glucosinolates were measured in the leaves of perennial wall rocket [Diplotaxis tenuifolia (L.) DC.], and annual garden rocket (Eruca sativa Mill.). HPLC-MS was used to identify glucoraphanin, 4-hydroxyglucobrassin and glucoerucin from perennial wall rocket, and glucoraphanin, glucobrassicin and 4-methoxyglucobrassicin from annual garden rocket. In separate experiments the responses of glucosinolates to harvest number, seasonal conditions, nitrogen supply and post-harvest storage conditions were measured.
For perennial wall rocket, season influenced the concentration of glucoraphanin, which were highest for the spring [379 µg kg(-1) fresh weight (FW)] and summer (317 µg kg(-1) FW) plantings. The concentration of 4-hydroxyglucobrassin was higher in the leaves of first harvest crops. This response was due to this glucosinolate not being detected in the leaves of second harvest crops. Thus, the parent glucosinolate was altered between the first and second harvests in response to the abiotic stresses caused by harvesting. For annual garden rocket, there was an interaction between the harvest number and season for all glucosinolates measured. However, no clear response was observed between these factors. Higher concentrations of glucobrassicin and 4-methoxyglucobrassicin were measured for first harvest leaves when compared to the second harvest. This was due to the absence of detection of these glucosinolates in the leaves of second harvested plants; consequently higher total glucosinolate concentrations were measured for the first harvest winter (1224 µg kg(-1) FW) and summer (864 µg kg(-1) FW) crops.
The concentrations of individual glucosinolates vary greatly over typical pre- and post-harvest commercial conditions. The absence of 4-hydroxyglucobrassin for perennial wall rocket, and glucobrassicin and 4-methoxyglucobrassicin for annual garden rocket between harvests, illustrates that abiotic stress from harvesting has the capacity to alter the types of glucosinolates in leaves. Concentrations do not generally decline during a typical storage period, indicating that the potential benefits of these compounds are not lost during post-harvest storage.
测定了多年生墙生火箭菜[Diplotaxis tenuifolia (L.) DC.]和一年生花园火箭菜（芝麻菜）叶片中三种最丰富的硫代葡萄糖苷的浓度变化。采用高效液相色谱-质谱联用（HPLC-MS）技术从多年生墙生火箭菜中鉴定出萝卜硫苷、4-羟基硫代葡萄糖苷和异硫氰酸烯丙酯，从一年生花园火箭菜中鉴定出萝卜硫苷、硫代葡萄糖苷和4-甲氧基硫代葡萄糖苷。在单独的实验中，测定了硫代葡萄糖苷对收获次数、季节条件、氮供应和收获后储存条件的响应。
对于多年生墙生火箭菜，季节影响萝卜硫苷的浓度，春季（379μg kg⁻¹鲜重）和夏季（317μg kg⁻¹鲜重）种植的植株中萝卜硫苷浓度最高。首次收获作物叶片中4-羟基硫代葡萄糖苷的浓度较高。这种响应是由于在第二次收获作物的叶片中未检测到这种硫代葡萄糖苷。因此，由于收获引起的非生物胁迫，母硫代葡萄糖苷在第一次和第二次收获之间发生了变化。对于一年生花园火箭菜，所测所有硫代葡萄糖苷的收获次数和季节之间存在相互作用。然而，在这些因素之间未观察到明显的响应。与第二次收获相比，首次收获叶片中硫代葡萄糖苷和4-甲氧基硫代葡萄糖苷的浓度较高。这是由于在第二次收获植株的叶片中未检测到这些硫代葡萄糖苷；因此，首次收获的冬季（1224μg kg⁻¹鲜重）和夏季（864μg kg⁻¹鲜重）作物中硫代葡萄糖苷的总浓度较高。
在典型的收获前和收获后商业条件下，单个硫代葡萄糖苷的浓度变化很大。多年生墙生火箭菜第二次收获时未检测到4-羟基硫代葡萄糖苷，一年生花园火箭菜第二次收获时未检测到硫代葡萄糖苷和4-甲氧基硫代葡萄糖苷，这表明收获引起的非生物胁迫有能力改变叶片中硫代葡萄糖苷的类型。在典型的储存期内，浓度一般不会下降，这表明这些化合物的潜在益处不会在收获后储存期间丧失。
