《植物生理学报》 2016, 52(1): 101-108

双酚A对玉米幼苗光合及抗氧化作用的影响

许艳梅, 贝丽霞^*, 张恒, 于高波, 杨克军, 赵长江^*, 徐晶宇, 贺琳, 石新新, 马丽峰, 范博文, 刘瑞

黑龙江八一农垦大学农学院, 黑龙江省教育厅寒地作物种质改良与栽培重点实验室, 黑龙江大庆163319

通信作者：贝丽霞；E-mail: beilixia@163.com; zhaocj15@126.com

摘　要：

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(P_n)、气孔导度(G_s)、蒸腾速率(T_r)升高, 高于(含) 5 mg•L^-1 BPA导致P_n、G_s、T_r显著下降, 胞间CO₂浓度(C_i)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。

关键词：BPA; 玉米; 生长; 光合作用; 抗氧化

收稿：2015-06-23   修定：2015-12-26

资助：国家科技支撑计划课题(2013BAD07B01-05/07)、国家自然科学基金(31101429)、黑龙江省教育厅科学技术研究项目(12511360)、黑龙江八一农垦大学引进人才科研启动基金(2011)和黑龙江八一农垦大学研究生创新项目(Y06)。

Effects of bisphenol A on photosynthesis and antioxidation of maize (Zea mays) seedlings

XU Yan-Mei, BEI Li-Xia^*, ZHANG Heng, YU Gao-Bo, YANG Ke-Jun, ZHAO Chang-Jiang^*, XU Jing-Yu, HE Lin, SHI Xin-Xin, MA Li-Feng, FAN Bo-Wen, LIU Rui

Agricultural College, Key Laboratory of Crop Germplasm Improvement and Cultivation in Cold Regions of Heilongjiang Province Education Department, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang 163319, China

Corresponding author: BEI Li-Xia; E-mail: beilixia@163.com; zhaocj15@126.com

Abstract:

The wide use of the materials containing bisphenol A (BPA) results in BPA release into the environment and produces safety hazard. Hence, in this study, we supplemented BPA to the root-soaking solution of the hybrid maize variety ‘Zhengdan 958’ and analyzed the effects of BPA on photosynthesis and antioxidation system. The results showed that BPA level below (including) 5 mg•L^-1 caused an obvious increase in terms of root length, aboveground fresh and dry weight of maize seedlings; while plant height, aboveground fresh and dry weight decreased significantly when BPA was above 5 mg•L^-1. The inhibition effects increased with increasing BPA concentration, notably leaf relative water content declined significantly under 5 mg•L^-1 BPA treatment. Net photosynthetic rate (P_n), stomatal conductance (G_s) and transpiration rate (T_r) elevated under 1.5 mg•L^-1 BPA treatment; above (including) 5 mg•L^-1 BPA led to a markedly decreasing in P_n, G_s and T_r, but an obvious increase in intercellular carbon dioxide concentration (C_i), which suggested that photosynthesis decline was mainly caused by non-stomatal limitation factors. Above (including) 10 mg•L^-1 BPA, the content of photosynthetic pigments declined. These results implied that the photosynthesis of maize seedlings was sensitive to BPA, but the changes in photosynthetic pigments content was not the main reason for the decline of photosynthesis. Under BPA treatment, MDA content gradually increased and displayed significant difference under 50 mg•L^-1 BPA, superoxide dismutase (SOD) activity firstly decreased and then increased, and the activities of peroxidase (POD) and catalase (CAT) revealed a promotion to some extent. During the recovery period, the photosynthetic parameters recovered obviously, the MDA content decreased, SOD activity increased, POD activity of changed in wave type. The study implied that the low BPA concentration promoted while high concentration suppressed growth of maize seedlings, which was resulted from the effect of BPA on photosynthesis; on the other hand, BPA treatment resulted in MDA accumulation, caused membrane lipid peroxidation, and increased antioxidant enzyme activity, thus regulated the ROS balance.

Key words: BPA; maize; growth; photosynthesis; antioxidation