Effects of zinc and molybdenum on European Bluestar ( Amsonia orientalis ): An in vitro study

Investigation of multidirectional toxicity induced by high-dose molybdenum exposure with Allium test

In this study, the multifaceted toxicity induced by high doses of the essential trace element molybdenum in Allium cepa L. was investigated. Germination, root elongation, weight gain, mitotic index (MI), micronucleus (MN), chromosomal abnormalities (CAs), Comet assay, malondialdehyde (MDA), proline, superoxide dismutase (SOD), catalase (CAT) and anatomical parameters were used as biomarkers of toxicity. In addition, detailed correlation and PCA analyzes were performed for all parameters discussed. On the other hand, this study focused on the development of a two hidden layer deep neural network (DNN) using Matlab. Four experimental groups were designed: control group bulbs were germinated in tap water and application group bulbs were germinated with 1000, 2000 and 4000 mg/L doses of molybdenum for 72 h. After germination, root tips were collected and prepared for analysis. As a result, molybdenum exposure caused a dose-dependent decrease (p < 0.05) in the investigated physiological parameter values, and an increase (p < 0.05) in the cytogenetic (except MI) and biochemical parameter values. Molybdenum exposure induced different types of CAs and various anatomical damages in root meristem cells. Comet assay results showed that the severity of DNA damage increased depending on the increasing molybdenum dose. Detailed correlation and PCA analysis results determined significant positive and negative interactions between the investigated parameters and confirmed the relationships of these parameters with molybdenum doses. It has been found that the DNN model is in close agreement with the actual data showing the accuracy of the predictions. MAE, MAPE, RMSE and R2 were used to evaluate the effectiveness of the DNN model. Collective analysis of these metrics showed that the DNN model performed well. As a result, it has been determined once again that high doses of molybdenum cause multiple toxicity in A. cepa and the Allium test is a reliable universal test for determining this toxicity. Therefore, periodic measurement of molybdenum levels in agricultural soils should be the first priority in preventing molybdenum toxicity.

Amelioration of lead toxicity by ascorbic acid in sugarcane (Saccharum officinarum L.) under in vitro condition

Agricultural sites are polluted with various metal ions worldwide. Ascorbic acid (AA) plays diverse roles in plant growth, development, and the regulation of cellular mechanisms against environmental stress. This study provides the relationship between morphological and biochemical parameters involved in the amelioration of Pb toxicity in three sugarcane (Saccharum officinarum L.) genotypes (YT-53, CP-77-400, NSG-59) by using six concentrations of Pb(NO₃)₂ under in vitro conditions. Morphological and biochemical parameters of ascorbic acid pretreated and non-pretreated calli were compared at each Pb(NO₃)₂ concentration. Ascorbic acid-pretreated calli have better callus growth and regeneration potential than non-treated calli under increased Pb concentration. Biochemical parameters such as antioxidant enzyme activity (peroxidase (POD), superoxide dismutase (SOD), catalase (CAT)) increased under increased Pb concentration. Ascorbic acid pretreatment further enhanced the POD and SOD activity, while CAT activity and total soluble protein contents of pretreated calli did not change significantly. Ascorbic acid ameliorated the Pb toxicity morphologically but showed uneven behavior towards biochemical parameters. Different genotypic behaviors versus different treatments were also observed. In the future, information from this study can be used to develop the metal-resistant sugarcane genotype against metal stress under in vitro conditions.