جستجوی مقالات مرتبط با کلیدواژه "تنش غیرزنده" در نشریات گروه "بیوتکنولوژی و ژنتیک گیاهی"

Silver nanoparticles are being extensively used in a broad range of applications in our daily routine life. In the present study, it was investigated if citric acid (CA) and hydrogen sulfide (H2S) can mitigate adverse effects of silver nanoparticles (AgNPs) in green bean plants. Green bean seedlings were applied with AgNPs either through soil drenching or foliar spray and were then treated with different concentrations of citric acid and NaHS, as H2S donor. Results indicated that AgNPs induced several stresses in green bean plants. Concomitant foliar and soil appliaction of nanoparticles caused adverse effects on photosynthetic pigments and reduced carotenoid and protein contents, while increasing H2O2 content and superoxide dismutase (SOD), and ascorbate peroxidase (APX) activities. It was revealed that citric acid and H2S application significantly alleviated adverse effects of AgNPs. In the plants challenged with AgNPs, the highest rates of catalase (CAT), glutathione S-transferase (GSTs), and malondialdehyde (MDA) activities were recorded, while these parameters were reduced when plants were also treated with H2S. Application of 1.5 g/L of citric acid caused sharp decreases in CAT, GST and MDA activities. Among the treatments, the highest levels of APX, SOD, and anthocyanin were observed in the plants treated with AgNPs trough both foliar and soil drench method without citric acid and H2S treatment. The findings of the present study would increase our knowledge of the interaction of plants with heavy metals and would be useful for designing sophisticated methods for reducing the damages in the stressed plants.

Under osmotic stresses, proline accumulation is an important response of plants to these conditions. Proline is a compatible osmolyte which affects many cellular and molecular aspects of plant in both normal and stressful situations. Proline is shown to be involved in plant development in normal condition and in conferring resistance to plant under biotic and abiotic stresses. Therefore, many surveys have already been designed to unveil its mechanisms and signaling pathway, so that it might be an insight into resolving growing challenge of agriculture, drought and soil salinity. Δ1-pyrroline-5-carboxylate synthetase (P5CS), one of two main enzymes in proline biosynthesis pathway from glutamate precursor, has been demonstrated to play significant role in proline accumulation in plants under water stresses. Regarding the role of P5CS under osmotic stress, there are controversial observations in various plants, hence making it still unknown, whether P5CS is rate-limiting enzyme in the pathway or not. Obviously, transgene P5CS is proved to give higher resistance to transgenic plants under drought and salinity, by elevating proline content. In this literature, proline and its identified various functions in plants, characteristics of P5CS enzyme, signals, inducers and inhibitors of P5CS gene, expression pattern of P5CS under differential conditions in studied plant species are discussed. Finally, we have reviewed generated transgenic plants overexpressing P5CS and consequences of these transformations.