Stress Effect Induced by Microplastics Coupled with Acid Rain, on Garden Cress, During Short and Long Time: Two Exposures in Comparison

Aim: Plastics, and acid rain, are the results of the anthropogenic activities; although, the injuries caused by acidic precipitation to plants are well known, what happen if acid rain is coupled with microplastics pollution? Methods: In this experiment, we simulated, under controlled condition, a contaminated area from four different kinds of Microplastics (MPs): Polyethylene (PE), Polyvinylchloride (PVC), commercial mixture (PE + PVC) and Polypropylene (PP) subjected to acidic precipitation on Lepidium sativum, both in short then long exposures. At the end of experimentation were analysed: i) plant biometrical parameters (percentage inhibition of seed germination, plant height, leaf number and fresh biomass productions); and ii) oxidative stress (e.g., levels of hydrogen peroxide, glutathione, and ascorbic acid). On plant subjected to long exposure are quantified also: lipidic peroxidation through Malondialdehyde (MDA) concentration, Aminolevulinic Acid (AlA), pigments (Chl-a, Chl-b, carotenoids) and soluble sugars. Results: Our results suggest that root system is more sensitive to MPs coupled with acid rain then above ground biomass. Furthermore, in short exposure toxicity begin with PE+ treatments to shift towards PVC+ toxicity in long exposure at radical level. Conclusion: Our experiment demonstrates that different kinds of microplastics supplied with acid rain are able to interfere in different ways both in short and in long exposure, but also at shoot and root levels, on garden cress.

Intense subaerial weathering of eolian sediments in Gale crater, Mars

After over 8 years of successful surface operations on Mars, the Curiosity rover has revealed much about the environment in Gale crater. Despite early observations of a lacustrine environment, few of the subsequent deposits exhibit demonstrable lacustrine character. We suggest instead that most of the stratigraphic section explored to date can be best explained as eolian and/or volcaniclastic sediments subaerially chemically weathered by acidic precipitation in a reduced atmosphere. Most of the deposits in Gale crater seemingly did not form in an ancient lake, but the results nonetheless shed considerable light on ancient climate, environmental change, and the astrobiology of Mars. Discoveries by Curiosity provide a critical piece to Mars’ global alteration puzzle.

Removal of anti-nutritional factors of rapeseed protein isolate (RPI) and toxicity assessment of RPI

We wished to prepare detoxified rapeseed protein isolate (RPI) by phytase/ethanol treatment based on alkaline extraction and acidic precipitation. Contents of protein, fat, ash, moisture, crude fiber, glucosinolates, phytic acid,...

Aluminium–silicon interactions in higher plants: an update

Aluminium (Al) and silicon (Si) are abundant in soils, but their availability for plant uptake is limited by low solubility. However, Al toxicity is a major problem in naturally occurring acid soils and in soils affected by acidic precipitation. When, in 1995, we reviewed this topic for the Journal of Experimental Botany, it was clear that under certain circumstances soluble Si could ameliorate the toxic effects of Al, an effect mirrored in organisms beyond the plant kingdom. In the 25 years since our review, it has become evident that the amelioration phenomenon occurs in the root apoplast, with the formation of hydroxyaluminosilicates being part of the mechanism. A much better knowledge of the molecular basis for Si and Al uptake by plants and of Al toxicity mechanisms has been developed. However, relating this work to amelioration by Si is at an early stage. It is now clear that co-deposition of Al and Si in phytoliths is a fairly common phenomenon in the plant kingdom, and this may be important in detoxification of Al. Relatively little work on Al–Si interactions in field situations has been done in the last 25 years, and this is a key area for future development.