Search

Cadmium stress is one of the chief environmental cues that can substantially reduce plant growth. In the present research, we studied the effect of jasmonic acid (JA) and gibberellic acid (GA3) applied individually and/or in combination to chickpea (Cicer arietinum) plants exposed to 150 µM cadmium sulphate. Cadmium stress resulted in reduced plant growth and pigment contents. Moreover, chickpea plants under cadmium contamination displayed higher levels of electrolytic leakage, H2O2, and malonaldehyde, as well as lower relative water content. Plants primed with JA (1 nM) and those foliar-fed with GA3 (10–6 M) showed improved metal tolerance by reducing the accumulation of reactive oxygen species, malonaldehyde and electrolytic leakage, and increasing relative water content.. Osmoprotectants like proline and glycinebetaine increased under cadmium contamination. Additionally, the enzymatic activities and non-enzymatic antioxidant levels increased markedly under Cd stress, but application of JA as well as of GA3 further improved these attributes. Enzymes pertaining to the ascorbate glutathione and glyoxylase systems increased significantly when the chickpea plants were exposed to Cd. However, JA and GA3 applied singly or in combination showed improved enzymatic activities as well as nutrient uptake, whereas they reduced the metal accumulation in chickpea plants. Taken together, our findings demonstrated that JA and GA3 are suitable agents for regulating Cd stress resistance in chickpea plants. [ABSTRACT FROM AUTHOR]

Ingestion of natural food containing heavy metals is the most likely route of human exposure to the metals. Within the human body, heavy metals are deposited in bone and fat tissues, overlapping noble minerals can cause an array of diseases. Tea (camellia sinensis L) is among the most widely consumed nonalcoholic beverage. This study aimed to investigate and measure the concentrations of heavy metals and minerals in tea from 15 different brands consumed in Saudi Arabia to assess the health risk associated with its consumption and to compare the heavy metal contents with the permissible limits established by the USP and WHO. The mineral and metal contents (Fe, Cu, Zn, Pb, As, Cd) were analyzed using atomic absorption spectroscopy. The results revealed that the mean concentration were in the order: Mg> Fe> As> Cd> Zn> Pb. The average concentrations of Mg, Fe, Zn, As, Cd and Pb were 93.0, 6.14, 0.20, 1.75, 0.38 and 0.15 mg/kg, respectively Significant positive correlation (p > 0.5) were observed between pairs of Fe-Zn (0.617), Cd-Zn (0.596), Cd-As (0.595) and Zn-As (0.571). EDI values in black tea were higher than those in green tea, suggesting that black tea may pose a more serious health risk to humans than green tea. However, THQ values in green tea were all less than 1, indicating that the consumption of green tea would not result in any significant health risk of heavy metals for consumers. All the minerals and heavy metal were below the maximum permissible limits stipulated by the USP and WHO. [ABSTRACT FROM AUTHOR]

Cropping system models are widely used tools for simulating the growth and development of crops at field scale. However, it is often difficult to satisfy their detailed input and output data requirements for a proper evaluation of model. In this study, expert knowledge data were used as alternative source to fulfil these data requirements. The model was first calibrated for major crops of the studied area and then evaluated for the same crops by using expert knowledge data. Results showed that the model accurately simulated above-ground biomass and grain yield with a relative root mean square error (RRMSE) of 20% and 17%, respectively. On the other hand, simulated results were less satisfactory for N uptake and cumulated evapotranspiration with RRMSE of 27% and 31%, respectively. The model simulated cumulative variables more accurately than dynamic variables. The results of this study suggest that expert knowledge can be used to get data for intermediate variables rarely measured in experiments used for calibration (green leaf area index, actual evapotranspiration, rooting depth) in typical crop management conditions in the region. This approach enables a global and dynamic evaluation of cropping system models when experimental data is unavailable for large heterogeneous areas in a region. [ABSTRACT FROM PUBLISHER]