Effect of exogenous taurine on growth, oxidative defense, and nickel (Ni) uptake in canola (Brassica napus L.) under Ni stress

Unravelling soybean responses to early and late Tetranychus urticae (Acari: Tetranychidae) infestation

Soybean is a crucial source of food, protein, and oil worldwide that is facing challenges from biotic stresses. Infestation of Tetranychus urticae Koch (Acari: Tetranychidae) stands out as detrimentally affecting plant growth and grain production. Understanding soybean responses to T. urticae infestation is pivotal for unravelling the dynamics of mite-plant interactions. We evaluated the physiological and molecular responses of soybean plants to mite infestation after 5 and 21 days. We employed visual/microscopy observations of leaf damage, H2O2 accumulation, and lipid peroxidation. Additionally, the impact of mite infestation on shoot length/dry weight, chlorophyll concentration, and development stages was analysed. Proteomic analysis identified differentially abundant proteins (DAPs) after early (5 days) and late (21 days) infestation. Furthermore, GO, KEGG, and protein-protein interaction analyses were performed to understand effects on metabolic pathways. Throughout the analysed period, symptoms of leaf damage, H2O2 accumulation, and lipid peroxidation consistently increased. Mite infestation reduced shoot length/dry weight, chlorophyll concentration, and development stage duration. Proteomics revealed 185 and 266 DAPs after early and late mite infestation, respectively, indicating a complex remodelling of metabolic pathways. Photorespiration, chlorophyll synthesis, amino acid metabolism, and Krebs cycle/energy production were impacted after both early and late infestation. Additionally, specific metabolic pathways were modified only after early or late infestation. This study underscores the detrimental effects of mite infestation on soybean physiology and metabolism. DAPs offer potential in breeding programs for enhanced resistance. Overall, this research highlights the complex nature of soybean response to mite infestation, providing insights for intervention and breeding strategies.

Pervasive influence of heavy metals on metabolic pathways is potentially relieved by hesperidin to enhance the phytoremediation efficiency of Bassia scoparia

Hesperidin (HSP), a flavonoid, is a potent antioxidant, metal chelator, mediator of signaling pathways, and regulator of metal uptake in plants. The study examined the ameliorative effects of HSP (100 μM) on Bassia scoparia grown under excessive levels of heavy metals (zinc (500 mg kg-1), copper (400 mg kg-1), cadmium (100 mg kg-1), and chromium (100 mg kg-1)). The study clarifies the underlying mechanisms by which HSP lessens metabolic mayhem to enhance metal stress tolerance and phytoremediation efficiency of Bassia scoparia. Plants manifested diminished growth because of a drop in chlorophyll content and nutrient acquisition, along with exacerbated deterioration of cellular membranes reflected in elevated reactive oxygen species (ROS) production, lipid peroxidation, and relative membrane permeability. Besides the colossal production of cytotoxic methylglyoxal, the activity of lipoxygenase was also higher in plants under metal toxicity. Conversely, hesperidin suppressed the production of cytotoxic ROS and methylglyoxal. Hesperidin improved oxidative defense that protected membrane integrity. Hesperidin caused a more significant accumulation of osmolytes, non-protein thiols, and phytochelatins, thereby rendering metal ions non-toxic. Hydrogen sulfide and nitric oxide endogenous levels were intricately maintained higher in plants treated with HSP. Hesperidin increased metal accumulation in Bassia scoparia and thereby had the potential to promote the reclamation of metal-contaminated soils.

Effect of hesperidin on growth, photosynthesis, antioxidant systems and uptake of cadmium, copper, chromium and zinc by Celosia argentea plants

Rapid industrialization and extensive agricultural practices are the major causes of soil heavy metal contamination, which needs urgent attention to safeguard the soils from contamination. However, the phytotoxic effects of excessive metals in plants are the primary obstacle to efficient phytoextraction. The present study evaluated the effects of hesperidin (HSP) on metals (Cu, Cd, Cr, Zn) phytoextraction by hyperaccumulator (Celosia argentea L.) plants. For this purpose, HSP, a flavonoid compound with strong antioxidant potential to assist metal phytoextraction was used under metal stress in plants. Celosia argentea plants suffered significant (P ≤ 0.001) oxidative damage due to the colossal accumulation of metals (Cu, Cd, Cr, Zn). However, HSP supplementation notably (P ≤ 0.001) abated ROS generation (O2•‒, •OH, H2O2), lipoxygenase activity, methylglyoxal production, and relative membrane permeability that clearly indicated HSP-mediated decline in oxidative injury in plants. Exogenous HSP improved (P ≤ 0.001) the production of non-protein thiol, phytochelatins, osmolytes, and antioxidant compounds. Further, HSP enhanced (P ≤ 0.001) H2S and NO endogenous production, which might have improved the GSH: GSSG ratio. Consequently, HSP-treated C. argentea plants had higher biomass alongside elevated metal accumulation mirrored as profound modifications in translocation factor (TF), bioaccumulation coefficient (BAC), and bioconcentration factor (BCF). In this context, HSP significantly enhanced TF of Cr (P ≤ 0.001), Cd (P ≤ 0.001), and Zn (P ≤ 0.01), while BAC of Cr (P ≤ 0.001), Cd (P ≤ 0.001), and Zn (P ≤ 0.001). Further, BCF was significant (P ≤ 0.05) only in plants grown under Cr-spiked soil. Overall, HSP has the potential for phytoremediation of metals by C. argentea, which might be a suitable strategy for metal-polluted soils.