The rice ingestion rate in Madagascar is among the highest globally; however studies concerning metal(loid) concentrations in Madagascar rice are lacking. For Madagascar unpolished rice (n = 51 landraces), levels of toxic elements (e.g., total mercury, methylmercury, arsenic and cadmium) as well as essential micronutrients (e.g., zinc and selenium) were uniformly low, indicating potentially both positive and negative health effects. Aside from manganese (Wilcoxon rank sum, p < 0.01), no significant differences in concentrations for all trace elements were observed between rice with red bran (n = 20) and brown bran (n = 31) (Wilcoxon rank sum, p = 0.06–0.91). Compared to all elements in rice, rubidium (i.e., tracer for phloem transport) was most positively correlated with methylmercury (Pearson's r = 0.33, p < 0.05) and total mercury (r = 0.44, p < 0.05), while strontium (i.e., tracer for xylem transport) was least correlated with total mercury and methylmercury (r < 0.01 for both), suggesting inorganic mercury and methylmercury were possibly more mobile in phloem compared to xylem.

Phytoremediation is a strategy to employ plants to recover high quantities of metals in the soil into the harvestable parts such as shoots and roots. High levels of Cd and lead (Pb) in the soil cause several stress symptoms in plants including a decrease in growth, reduced root growth, and carbohydrate metabolism. In this study, Saravan and HGS-867 as local landrace and Indian guar variety were selected to investigate the effect of the application of Pb (0, 40, 150, and 200 mg/l) and the cadmium (0, 25, 50, and 100 mg/l) on phonological, yield parameters, and phytoremediation assessment. The results showed that Pb translocation factor (TF) was significant in Pb×Cd and Pb×Cd×G (genotype) at p<0.01 and in Pb×G at p<0.05. Pb bioconcentration factor (BCF) was significant (p<0.01) in all treatments except Cd and Cd×G treatments. Mean comparison of the data showed that the number of flowers, leaves, and clusters in plant decreased significantly with increasing Pb content. With increasing Cd concentration, the number of branches, height, the number of seeds, clusters, and leaves for each plant decreased significantly at the level of 1%. The maximum TF was observed in Pb at 40 mg/l in the HG-867 variety. Moreover, the Saravan landrace exposed to Cd (100 mg/l) showed the highest value of BCF (Cd). The gum percentage significantly decreased with increasing concentrations of Pb and Cd. Pearson’s correlation analysis indicated that plant height, number of pods/plant, root length, biomass, and pod length had a positive correlation with seed yield and a negative correlation with TF (Pb) and BCF (Pb). The results suggest that according to TF, BCF, and BAC, C. tetragonoloba L. can be effectively used as a good accumulator of toxic metals in contaminated soils.

Glyphosate-based herbicides (GBHs) are widely used worldwide. Glyphosate (GLP) is the main active component of GBHs. The presence of GBH residues in the environment has led to the exposure of animals to GBHs, but the mechanisms of GBH-induced nephrotoxicity are not clear. This study investigated the effects of GBHs on piglet kidneys. Twenty-eight healthy female hybrid weaned piglets (Duroc × Landrace × Yorkshire) with an average weight of 12.24 ± 0.61 kg were randomly divided into four treatment groups (n=7 piglets/group) that were supplemented with Roundup® (equivalent to GLP concentrations of 0, 10, 20, and 40 mg/kg) for a 35-day feeding trial. The results showed that the kidneys in the 40-mg/kg GLP group suffered slight damage. Roundup® significantly decreased the activity of catalase (CAT) (P=0.005) and increased the activity of superoxide dismutase (SOD) (P=0.029). Roundup® increased the level of cystatin-C (Cys-C) in the plasma (linear, P=0.002 and quadratic, P=0.015). The levels of neutrophil gelatinase–associated lipocalin (NGAL) in plasma increased linearly (P=0.007) and quadratically (P=0.003) as the dose of GLP increased. The mRNA expression of intercellular cell adhesion molecule-1 (ICAM-1) in the 20-mg/kg GLP group was increased significantly (P<0.05). There was a significant increase in the mRNA levels of pregnenolone X receptor (PXR), constitutive androstane receptor (CAR), and uridine diphosphate glucuronosyltransferase 1A3 (UGT1A3) (P<0.05). Our findings found that kidney nuclear xenobiotic receptors (NXRs) may play an important role in defense against GBHs.

Cadmium (Cd) pollution is a prominent environment problem, and great interests have been developed towards the molecular mechanism of Cd accumulation in plants. In this study, we conducted combined transcriptomic, proteomic and biochemical approaches to explore the detoxification of a Cd-hyperaccumulating turnip landrace exposed to 5 μM (T5) and 25 μM (T25) Cd treatments. A total of 1090 and 2111 differentially expressed genes (DEGs) and 161 and 303 differentially expressed proteins (DEPs) were identified in turnips under T5 and T25, respectively. However, poor correlations were observed in expression changes between mRNA and protein levels. The enriched KEGG pathways of DEGs with a high proportion (> 80%) of upregulated genes were focused on the flavonoid biosynthesis, sulphur metabolism and glucosinolate biosynthesis pathways, whereas those of DEPs were enriched on the glutathione metabolism pathway. This result suggests that these pathways contribute to Cd detoxification in turnips. Furthermore, induced antioxidant enzymes, heat stock proteins and stimulated protein acetylation modification seemed to play important roles in Cd tolerance in turnips. In addition, several metal transporters were found responsible for the Cd accumulation capacity of turnips. This study may serve as a basis for breeding low-Cd–accumulating vegetables for foodstuff or high-Cd–abstracting plants for phytoremediation.

Phytoextraction is a phytoremediation technique used for remediating polluted soils and it greatly relies on the plants’ capacities to accumulate contaminants. Turnip is a high cadmium (Cd)-accumulating plant. We compared the Cd tolerance, growth, and Cd accumulation characteristics of two turnip landraces with three additional commonly known high Cd-accumulating species to systematically estimate its Cd phytoremediation potential. Results showed that the turnips could tolerate relatively lower Cd concentrations than other plants. Growth characteristics analyses indicated that the turnips initially grew rapidly and then gradually slowed down, and their photosynthetic parameters indicated that biomass accumulation was easily affected by light. However, the Cd uptake and translocation capacities of the two turnip landraces were higher than those of Phytolacca americana Linn. and Bidens pilosa Linn. but close to that of Brassica napus Linn.. Ultimately, large amounts of Cd accumulated in turnips during early growth and slightly increased as the fleshy roots increased in size. Based on these findings, the present turnip landraces have potential for soil remediation, but additional research is needed before these landraces can be practically used. Moreover, turnips are good candidates for studying the molecular mechanism of high Cd accumulation in plants.

In the Brazilian wet and dry seasons, common beans (Phaseolus vulgaris L.) are grown under rainfed conditions with unexpected episodes of drought and high temperatures. The objective of this study was to evaluate the physiological mechanisms associated with drought adaptation traits in landraces and line/cultivars of beans from the Andean and Mesoamerican gene pools. Twenty-five genotypes, contrasting in terms of drought tolerance, were evaluated in a phenotyping platform under irrigated and rainfed conditions. Agronomic and physiological parameters such as grain yield, shoot structures, gas exchange, water potential, and osmotic adjustment were evaluated. The stress intensity was estimated to be 0.57, and the grain yield reduction ranged from 22 to 89%. Seven accessions, representative of the Andean and Mesoamerican germplasm (CF 200012, CF 240056, CF 250002, CF 900004, CNF 4497, CNF 7382, and SEA 5), presented superior performance in grain yield with and without stresses. The physiological responses under abiotic stresses were highly variable among the genotypes, and two Mesoamerican accessions (CF 200012 and SEA 5) showed more favorable adaptive responses. As the main secondary physiological traits, gas exchange and osmotic adjustment should be evaluated together with the grain yield to increase the selection efficiency of abiotic stresses-tolerant common bean lines.

Constant exposure of the living ecosystems to heavy metals, like cadmium (Cd), induces a detectable change at the biochemical and genetic level. Repeated application of phosphate fertilizers in paddy fields, leads to increase in Cd content of soil. Cd being highly mobile is transported to shoot and grain, thereby entering into the food chain of animal system. In the present study, treatment of 7-day old rice seedlings with 10 μM cadmium chloride resulted in Cd toxicity across the seven non-aromatic and six aromatic rice cultivars and landraces used for the study. Free proline and malondialdehyde content of treated samples were higher in comparison to the untreated samples, which indicated Cd induced tissue damage in plants. Photosynthetic pigment content of treated samples was also found to be much lower in comparison to the untreated samples, which is probably due to peroxidation of membrane, leading to compromised and lower photosynthetic efficiency of treated plants. At the genetic level, Randomly Amplified Polymorphic DNA assay was found to efficiently detect the genetic polymorphisms (caused by alterations in DNA bases) induced by Cd. Production of unique polymorphic bands in Cd-treated plants helps in assessment of the degree of damage Cd imparts on the plant system. Cluster analysis was performed and the rice genotypes were grouped into five distinct clusters, with IR64 and Tulsibhog in two distinct groups. Based on the variability in responses, the 13 rice genotypes were grouped into sensitive and tolerant ones.