问题描述：
英语翻译
摘要：研究了不同砷胁迫浓度、不同胁迫时间对小白菜幼苗叶片生理生化指标的影响.结果显示：随着As胁迫浓度升高,小白菜幼苗叶片中可溶性糖（SS）含量、游离脯氨酸（Pro）含量均也随着逐渐增加,丙二醛（MDA）含量呈先下降后上升,随着胁迫时间的延长,MDA含量也较比增加.低浓度的As对蛋白质含量、过氧化物酶（POD）活性、叶绿素a、叶绿素b均具有促进作用,呈先升后降的趋势,并随着胁迫时间的延长,都有一定的变化幅度.研究结果说明：小白菜对重金属的胁迫具有一定的抗性,过高的胁迫浓度会对小白菜幼苗生长发育造成毒害,但是小白菜可以通过自身的防御系统对自己进行保护使毒害降低.
关键词：小白菜；砷；生理生化
问题解答：
我来补答
Abstract: The author studied the physiological and biochemical indexes of cabbage seedling leaves under the action of arsenic stress with different concentrations and in different stressing durations. The results show that the contents of both soluble sugar (SS) and free proline (Pro) in the cabbage seedling leaves gradually go higher along with the As stress being thicker and thicker. The content of malondialdehyde (MDA) decreases first and then increases. With the stressing time goes longer, the MDA content increases later. Arsenic with low concentrations promotes the protein content, peroxidase (POD) activity, chlorophyll a content and chlorophyll b content. Both the activity and contents increase first and then decrease. With the stress time going longer, there are some changes. The study results show that: cabbage seedlings have a certain resistance to the stress of heavy metals. High stress concentrations are bound to jeopardize the growth of cabbage seedlings, but they can protect themselves using their own defense systems to minimize the poisoning.
Keywords: cabbage seedling; arsenic; physiological and biochemical;
