Gene expression and morphological responses of Lolium perenne L. exposed to cadmium (Cd2+) and mercury (Hg2+).

Soil contamination with heavy metals is a major problem worldwide, due to the increasing impact mainly caused by anthropogenic activities. This research evaluated the phytoremediation capacity of, Lolium perenne for heavy metals such as cadmium (Cd2+) and mercury (Hg2+), and the effects of these metals on morphology, biomass production, and the changes on gene expression. Seeds of L. perenne were exposed to six concentrations of Cd2+ and Hg2+ in the range of 0 to 25 mg L-1, and two mixtures of Cd2+-Hg2. The Non-Observed Effect Level (NOEL) was established with dose response curves and the expression of specific genes was evaluated applying a commercially available quantitative reverse transcription (RT-qPCR) assay. There was no significant effect when exposing the seeds to Hg2+, for Cd2+ the maximum concentration was established in 0.1 mg L-1, and for the two concentrations of mixtures, there was a negative effect. An increase of expression of genes that regulate antioxidant activity and stress was found when the plant was exposed to heavy metals. Given the high tolerance to metals analyzed that was reflected both, the development of the plant and in its molecular response, these results highlight that L. perenne is a plant with phytoremediator potential.

Preliminary study of the production of metabolites from in vitro cultures of C. ensiformis.

BACKGROUND: Canavalia ensiformis is a legume native to Central and South America that has historically been a source of protein. Its main proteins, urease, and lectin have been extensively studied and are examples of bioactive compounds. In this work, the effect of pH and light effects on the growth of C. ensiformis were analyzed. Also, the bioactive compounds such as phenols, carotenoids, chlorophyll a/b, and the growth of callus biomass of C. ensiformis from the effect of different types of light treatments (red, blue and mixture) were evaluated. Likewise, the antioxidative activity of C. ensiformis extracts were studied and related to the production of bioactive compounds. For this, a culture of calluses obtained from seeds were carried out. For the light experiments, polypropylene boxes with red, blue, combination (1/3, 3/1 and 1/1 R-B, respectively) lights and white LED were used as control. In each treatment, three glass containers with 25 ml of MS salts containing 0.25 g of fresh callus were seeded. RESULTS: The results have shown that the pH of the culture medium notably affects the increase in callogenic biomass. It shows that the pH of 5.5 shows better results in the callogenic growth of C. ensiformis with an average increase of 1.3051 g (198.04%), regarding the initial weight. It was found that the pH 5.5 and the 1/3 R-B LED combination had higher production of bioactive compounds and better antioxidant activity. At the same time, the red-light treatment was least effective. CONCLUSIONS: It was possible to find the ideal conditions of important growth under conditions of pH and light of C. ensiformis. Likewise, it is evaluated whether the production of compounds of interest, such as phenolic compounds and carotenoids, occurs under these conditions. The highest production of calluses occurs in the 1/3 R-B LED combined light treatment, which showed a significant increase in biomass, followed by B. From this study, it could be demonstrated that C. ensiformis produces compounds such as phenols and carotenoids in vitro culture that are essential for the antioxidant activity of the plant.