We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Effects of microplastics and heavy metal stress on the growth and physiological characteristics of pioneer plant Avicennia marina
Summary
Researchers studied how mangrove plants respond to combined pollution from microplastics and heavy metals at levels found in the environment. The combination caused more oxidative stress and growth problems than either pollutant alone, disrupting the plants' defense systems. Since mangroves protect coastlines and filter water for coastal communities, damage to these ecosystems from microplastic-heavy metal pollution could have indirect effects on human well-being.
Mangrove plants grow in muddy and swampy areas where the land and sea meet and are threatened by various pollutants. In the present study, Avicennia marina (Forsk.) Vierh. (A.marina), the pioneer species in mangrove, was selected as model plant. A composite pollution model of microplastics (polypropylene [PP], polyethylene [PE], and polyamide [PA]) and multiple heavy metals (Cr, Cu, Pb, Zn, Cd, Mn, Co, Hg, As, and Ni) at environmental concentrations was constructed to explore the effects of dual stress on seedling growth and metabolism. Over the 65-days co-exposure, no lethal effects were observed among any contaminant treatments. In contrast, the PP and heavy metal (PP) and PA and heavy metal (PA) groups promoted the growth and development of the seedlings. The PP and PA treatments increased the soluble protein content of seedling leaves to 4.4 and 3.1 times of the heavy metal (H) treatment, respectively. Free proline content was approximately 58 % higher in the PP treatment group than in the H group. PE and heavy metal (PE) exposure significantly inhibited enzyme activities related to nitrogen uptake and transformation in the root and leaf tissues of seedlings. In addition, higher concentrations and frequencies of reactive oxygen species accumulation were observed in root tissues of seedlings grown in sediment added PE and PA. These findings provide critical evidences to elucidate the toxicological effects of microplastics and heavy metals combined stress on mangrove plant.