Cadmium Tolerance During Seed Germination and Seedling Growth of Schinus molle (Anacardiaceae)

Abstract

Cadmium (Cd) is one of the most toxic elements to plants, so Cd-tolerant trees should be used in reforestation or remediation systems. In this study the effects of Cd on seed germination and early seedling growth were evaluated in Schinus molle plants. Seeds of S. molle were treated with Cd at concentrations of 0 (control), 0.01, 0.02, 0.05, and 0.125 mM using Cd(NO 3) 2. Seed germination parameters and seedling growth traits were evaluated 33 days after the experiment started. Seeds and roots were sampled for anatomical evaluation and processed with plant microtechniques. No effects of Cd were found on the germination percentage of S. molle seeds. However, seedlings' shoot and root fresh masses and lengths increased with Cd treatment. Cadmium increased root cortex and endodermis thickness and reduced the percentage of vascular tissues in seedlings. Schinus molle seeds and seedlings thus showed tolerance to Cd related to anatomical adaptations.

The role of reactive oxygen species and nitric oxide in the formation of root cortical aerenchyma under cadmium contamination

“…The proportion of the vascular cylinder was reduced under relatively high Cd concentrations together with NO, and a reduction in the vascular cylinder diameter, in turn, affected the water transport capacity of the roots. A similar reduction in the vascular cylinder diameter was observed in Schinus molle plants under Cd stress (Baroni et al, 2020), although only relatively high doses of NO reduced the proportion of the vascular cylinder, possibly for the purpose of reducing the transport of Cd to the shoots. However, NO acts as an antagonistic molecule in the presence of Cd; NO behaves as a signaling molecule that indicates a lack of stress in plants, thus avoiding a decrease in vascular cylinder diameter.…”

Photosynthetic apparatus performance and anatomical modulations of Alcantarea imperialis (Bromeliaceae) exposed to selenium during in vitro growth

“…Even though Se modulated the root architecture of A. imperialis plants, this metalloid did not interfere with the roots' anatomical traits. Plants under stress promoted by an element (e.g., cadmium, zinc, lead, and sodium) in contact with the roots may show alterations in thickness of the endodermis and/or a number of xylem vessels (Rodrigues et al 2017, Al-Aradi et al 2020, Baroni et al 2020. The endodermis has a protective function because it acts as an apoplastic barrier controlling the radial transport of water and ions, to reduce the entry of contaminants from the surroundings to the vascular cylinder (Rodrigues et al 2017).…”

A Physiological behavior and tolerance of Lactuca sativa to lead nitrate and silver nitrate heavy metals

“…Contaminant metals in the soil can be classified as heavy metals or trace elements. Heavy metals are elements that normally give high toxicity to humans; among them, stand out the lead, cadmium, silver, mercury and chromium (Suryawanshi, et al, 2016;Baroni et al, 2020). Trace elements, on the other hand, are metals with lower toxicity and are often present in low concentrations, and some of them are considered biologically essential; however, some of these metals in specific situations may cause problems to ecosystems, causing pollution to water and soil (Ribeiro et al, 2019).…”