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由于含双酚A(bisphenol A,BPA)材料的广泛使用,致使其释放到环境中产生安全隐患。以玉米杂交品种‘郑单958’为材料,对玉米幼苗进行BPA浸根处理,分析其对光合和抗氧化系统的影响。结果表明,低于(含)5 mg·L~(-1) BPA处理引起玉米幼苗根长、地上鲜重及干重增加;高于5 mg·L~(-1) BPA导致株高、地上鲜重及干重显著下降,且随BPA浓度增加抑制效果加重,值得注意的是5 mg·L~(-1) BPA处理已导致叶片相对含水量显著下降。1.5 mg·L~(-1) BPA处理使得净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)升高,高于(含)5 mg·L~(-1) BPA导致Pn、Gs、Tr显著下降,胞间CO_2浓度(Ci)显著升高,表明光合下降主要是由非气孔限制因素引起,且高于(含)10 mg·L~(-1) BPA处理光合色素含量呈下降趋势,说明玉米幼苗光合作用对BPA响应较为敏感且光合色素含量可能并非是光合作用下降的主要原因。BPA处理下,MDA含量增加但只有50 mg·L~(-1) BPA处理增加显著,SOD活性先下降后升高,POD与CAT活性呈不同程度升高。恢复期,光合参数显著恢复,MDA含量较处理期相对下降,SOD活性逐渐升高,POD活性呈波动式变化。研究表明BPA对玉米幼苗生长表现出明显的“低促高抑”现象,一方面是由BPA对光合作用的“低促高抑”效应造成的;另一方面,BPA处理造成MDA积累,引发膜质过氧化,提高抗氧化酶活性,从而调控ROS动态平衡。
Due to the widespread use of bisphenol A (BPA) -based materials, it poses a potential safety hazard when released into the environment. With maize hybrid Zhengdan 958 as material, the corn seedlings were treated with BPA soaking, and their effects on photosynthesis and antioxidant system were analyzed. The results showed that under 5 mg · L -1 BPA treatment, the root length, aboveground fresh weight and dry weight of maize seedling were increased. Above 5 mg · L -1 BPA, plant height, Fresh weight and dry weight decreased significantly, and the inhibitory effect was aggravated with the increase of BPA concentration. It is noteworthy that 5 mg · L -1 BPA treatment had resulted in a significant decrease in relative leaf water content. BPA treatment at 1.5 mg · L -1 resulted in the increase of Pn, Gs and Tr, which was higher than that of 5 mg · L -1 BPA Pn, Gs, Tr decreased significantly, and the intercellular CO_2 concentration (Ci) increased significantly, indicating that photosynthesis decline is mainly caused by non-stomatal limitation and higher than that of BPA containing 10 mg · L -1 BPA Content showed a downward trend, indicating that photosynthesis of maize seedlings sensitive to BPA and photosynthetic pigment content may not be the main reason for the decline in photosynthesis. Under BPA treatment, MDA content increased but only 50 mg · L -1 BPA treatment significantly increased, SOD activity decreased first and then increased, POD and CAT activity increased to varying degrees. During the recovery period, the photosynthetic parameters recovered significantly, the content of MDA decreased compared with the treatment period, the SOD activity increased gradually and the POD activity fluctuated. The results showed that BPA showed a significant “low promoting and high inhibiting” phenomenon on the growth of maize seedlings, which was caused by the effect of BPA on photosynthesis; on the other hand, BPA treatment caused MDA Accumulation, triggering membranous peroxidation, increase antioxidant enzyme activity, thereby regulating ROS homeostasis.