Blake-Kalff MM, Harrison KR, Hawkesford MJ, Zhao FJ, McGrath SP
IACR-Rothamsted, Soil Science Department (M.M.A.B.-K., K.R.H., F.J.Z. , S.P.M.).
Plant Physiol. 1998 Dec;118(4):1337-44. doi: 10.1104/pp.118.4.1337.
The distribution of S to sulfate, glucosinolates, glutathione, and the insoluble fraction within oilseed rape (Brassica napus L.) leaves of different ages was investigated during vegetative growth. The concentrations of glutathione and glucosinolates increased from the oldest to the youngest leaves, whereas the opposite was observed for SO42-. The concentration of insoluble S was similar among all of the leaves. At sufficient S supply and in the youngest leaves, 2% of total S was allocated to glutathione, 6% to glucosinolates, 50% to the insoluble fraction, and the remainder accumulated as SO42-. In the middle and oldest leaves, 70% to 90% of total S accumulated as SO42-, whereas glutathione and glucosinolates together accounted for less than 1% of S. When the S supply was withdrawn (minus S), the concentrations of all S-containing compounds, particularly SO42-, decreased in the youngest and middle leaves. Neither glucosinolates nor glutathione were major sources of S during S deficiency. Plants grown on nutrient solution containing minus S and low N were less deficient than plants grown on solution containing minus S and high N. The effect of N was explained by differences in growth rate. The different responses of leaves of different ages to S deficiency have to be taken into account for the development of field diagnostic tests to determine whether plants are S deficient.
在营养生长期间，研究了不同年龄油菜（Brassica napus L.）叶片中硫向硫酸盐、硫代葡萄糖苷、谷胱甘肽以及不溶性部分的分配情况。谷胱甘肽和硫代葡萄糖苷的浓度从最老的叶片到最年轻的叶片逐渐增加，而硫酸根离子（SO42-）的情况则相反。所有叶片中不溶性硫的浓度相似。在硫供应充足时，最年轻的叶片中，总硫的2%分配给谷胱甘肽，6%分配给硫代葡萄糖苷，50%分配给不溶性部分，其余以硫酸根离子形式积累。在中间叶和最老的叶片中，总硫的70%至90%以硫酸根离子形式积累，而谷胱甘肽和硫代葡萄糖苷总共占硫的比例不到1%。当停止硫供应（缺硫）时，最年轻和中间叶中所有含硫化合物的浓度，尤其是硫酸根离子，均下降。在缺硫期间，硫代葡萄糖苷和谷胱甘肽都不是硫的主要来源。在含低氮缺硫营养液中生长的植物比在含高氮缺硫营养液中生长的植物缺硫程度轻。氮的这种影响可以通过生长速率的差异来解释。在开发田间诊断测试以确定植物是否缺硫时，必须考虑不同年龄叶片对缺硫的不同反应。
