ABSTRACT

Acid rain (AR) and atmospheric particulate matter (APM) are important environmental issues that often occur simultaneously in agricultural regions, the combined pollution of AR and atmospheric fine particles (PM_2.5) containing heavy metals has negatively affected the growth of seedlings and has become a hot research topic. In this paper, we established exposure scenarios to simulate the AR and the cadmium-containing PM_2.5 (PM_2.5-Cd) pollutions. Under the scenarios, hazardous impacts of AR and PM_2.5-Cd on growth, physiological and biochemical characteristics of pakchoi were evaluated. After being exposed simulated AR and PM_2.5-Cd for 21 days, our results indicate that: single treatment with either AR (pH 5.5) or PM_2.5-Cd, or a combined treatment of AR (pH 5.5) and PM_2.5-Cd (150, 300 μg·m⁻³) increased the growth of pack hoi seedlings. Combined treatments with low-acidity AR (pH 3.5) and PM_2.5-Cd (500 μg·m⁻³), significantly decreased the growth and the Soil and Plant Analyzer Development (SPAD) of pakchoi, and it also induced a significantly increase in foliar MDA content and catalase (CAT) activity, while decreasing peroxidase (POD) and superoxide dismutase (SOD) activity. The Cd concentration of leaves increased with an increasing PM_2.5-Cd concentration. Correlation analysis indicated that the growth and SPAD of pakchoi were highly correlated with the foliar MDA content and enzyme activities under the combined treatments with AR and PM_2.5-Cd treatment. Our results might serve as a guide to increase agricultural production and food crop safety in areas with high levels of AR and PM_2.5 pollution.

摘要

酸雨（AR）和大气颗粒物（APM）是农业区经常同时发生的重要环境问题，酸雨和含重金属的大气细颗粒物（PM _2.5）的联合污染对幼苗生长产生不利影响，已成为一个热门的研究课题。在本文中，我们建立了暴露场景来模拟 AR 和含镉 PM _2.5 (PM _2.5 -Cd) 污染。在这些情景下，评估了 AR 和 PM _2.5 -Cd 对小白菜生长、生理和生化特性的有害影响。暴露后模拟 AR 和 PM _2.5-Cd 21 天，我们的结果表明：AR (pH 5.5) 或 PM _2.5 -Cd单独处理，或 AR (pH 5.5) 和 PM _2.5 -Cd (150, 300 μg·m ^-3 ) 增加了包海苗的生长。低酸度AR（pH 3.5）和PM _2.5 -Cd（500 μg·m ^-3）的联合处理显着降低了小白菜的生长和土壤和植物分析仪的发育（SPAD），并且还诱导了小白菜的显着增加叶面 MDA 含量和过氧化氢酶 (CAT) 活性，同时降低过氧化物酶 (POD) 和超氧化物歧化酶 (SOD) 活性。叶子的 Cd 浓度随着 PM _{2.5 的}增加而增加-Cd 浓度。相关性分析表明，AR和PM _2.5 -Cd联合处理下小白菜的生长和SPAD与叶面MDA含量和酶活性高度相关。我们的结果可作为指导，以提高 AR 和 PM _2.5污染水平高的地区的农业生产和粮食作物安全。