硫(S)作为植物必须的大量元素在调节植物生长发育及响应非生物胁迫过程中具有重要的作用.本研究以番茄幼苗为材料,探究不同浓度S在 Cd 胁迫下对番茄植株生长及抗逆代谢的影响.结果表明,在缺S环境下植物生长明显受到抑制且 Cd的胁迫效应更加显著,1~4 mmol·L-1 S能够显著促进番茄幼苗的生物量累积并缓解由于 Cd 胁迫导致的生长缓慢现象.外源S显著提升抗逆性物质脯氨酸和可溶性蛋白的含量以缓解 Cd胁迫.此外,Cd 胁迫导致番茄幼苗氮(N)和磷(P)代谢受阻,植物体内N和P的赋存形式及分布发生明显变化,外源S的添加能够通过调节N代谢和P代谢的关键酶-硝酸还原酶、谷氨酰胺合成酶及酸性磷酸酶活性,促进番茄幼苗N和P的代谢过程,降低Cd对植物的毒性效应.
Sulfur(S),as a necessary macroelement,plays an important role in regulating plant growth and development,responding to abiotic stress.In this study,tomato seedlings were used to explore the effects of different concentrations of S on tomato plant growth and resist-ance metabolism under Cd stress.The results showed that plant growth significantly inhibi-ted and Cd stress effect was more significant under S-deficiency environment.1~4 mmol·L-1 S could significantly promote the biomass accumulation of tomato seedlings and alleviate the growth inhibition caused by Cd stress.Exogenous S significantly increased the contents of proline and soluble protein to alleviate Cd stress.In addition,Cd stress inhibi-ted the metabolism of nitrogen(N)and phosphorus(P)in tomato seedlings,and the occur-rence form and distribution of N and P in plants changed significantly.The addition of exoge-nous S could promote the metabolism of N and P in tomato seedlings by regulating the activi-ties of key enzymes of N metabolism and P metabolism,such as nitrate reductase,glutamine synthetase and acid phosphatase,reduce the toxic effect of Cd on plants.