Alleviation of cadmium toxicity in pea (Pisum sativum L.) through Zn-Lys supplementation and its effects on growth and antioxidant defense

Cadmium significantly impacts plant growth and productivity by disrupting physiological, biochemical, and oxidative defenses, leading to severe damage. The application of Zn-Lys improves plant growth while reducing the stress caused by heavy metals on plants. By focusing on cadmium stress and potential of Zn-Lys on pea, we conducted a pot-based study, organized under completely randomized block design CRD-factorial at the Botanical Garden of Government College University, Faisalabad. Both pea cultivars were grown in several concentrations of cadmium @ 0, 50 and 100 μM, and Zn-Lys were exogenously applied @ 0 mg/L and 10 mg/L with three replicates for each treatment. Cd-toxicity potentially reduces plant growth, chlorophyll contents, osmoprotectants, and anthocyanin content; however, an increase in MDA, H2O2 initiation, enzymatic antioxidant activities as well as phenolic, flavonoid, proline was observed. Remarkably, exogenously applied Zn-Lys significantly enhanced the plant growth, biomass, photosynthetic attributes, osmoprotectants, and anthocyanin contents, while further increase in enzymatic antioxidant activities, total phenolic, flavonoid, and proline contents were noticed. However, application of Zn-Lys instigated a remarkable decrease in levels of MDA and H2O2. It can be suggested with recommendation to check the potential of Zn-Lys on plants under cadmium-based toxic soil.

Foliar application of iron-lysine to boost growth attributes, photosynthetic pigments and biochemical defense system in canola (Brassica napus L.) under cadmium stress

In the current industrial scenario, cadmium (Cd) as a metal is of great importance but poses a major threat to the ecosystem. However, the role of micronutrient - amino chelates such as iron - lysine (Fe - lys) in reducing Cr toxicity in crop plants was recently introduced. In the current experiment, the exogenous applications of Fe - lys i.e., 0 and10 mg L - 1, were examined, using an in vivo approach that involved plant growth and biomass, photosynthetic pigments, oxidative stress indicators and antioxidant response, sugar and osmolytes under the soil contaminated with varying levels of Cd i.e., 0, 50 and 100 µM using two different varieties of canola i.e., Sarbaz and Pea - 09. Results revealed that the increasing levels of Cd in the soil decreased plant growth and growth-related attributes and photosynthetic apparatus and also the soluble protein and soluble sugar. In contrast, the addition of different levels of Cd in the soil significantly increased the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2), which induced oxidative damage in both varieties of canola i.e., Sarbaz and Pea - 09. However, canola plants increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and non-enzymatic compounds such as phenolic, flavonoid, proline, and anthocyanin, which scavenge the over-production of reactive oxygen species (ROS). Cd toxicity can be overcome by the supplementation of Fe - lys, which significantly increased plant growth and biomass, improved photosynthetic machinery and sugar contents, and increased the activities of different antioxidative enzymes, even in the plants grown under different levels of Cd in the soil. Research findings, therefore, suggested that the Fe - lys application can ameliorate Cd toxicity in canola and result in improved plant growth and composition under metal stress.

Impact of sodium pyrophosphate and static magnetic field on Haematococcus pluvialis: enhancement of astaxanthin accumulation, PAL, and antioxidant enzyme activities

The Haematococcus pluvialis microalga is known as a main source of astaxanthin with a strong antioxidant capacity and low growth rate. The induction of growth and astaxanthin content was established in H. pluvialis alga using a static magnetic field (SMF) and tetrasodium pyrophosphate (NaPP) as an inhibitor of isopentenyl pyrophosphate (precursor of astaxanthin biosynthesis) translocator between cytosol to plastid. NaPP (0.3 mM), SMF (4 mT), and their combinations were applied to the H. pluvialis cell culture. Results showed chlorophyll a and b were induced in H. pluvialis by SMF treatment, but didn't change significantly under NaPP. Astaxanthin content enhanced under NaPP, SMF, and their combination, and the highest astaxanthin content was obtained under NaPP after 21 days (late of stationary phase) of culture. A significant increase in total phenol and flavonoid contents, and activities of phenylalanine ammonia-lyase (PAL) and DPPH were observed under both NaPP and SMF treatments. In contrast to NaPP, SMF decreased H₂O₂ content, which was associated with more activity of SOD and CAT enzymes. These results revealed that NaPP and SMF might stimulate both phenol and astaxanthin biosynthesis pathways by impacting the activity of enzymes, and inhibition of IPP translocation by NaPP didn't affect astaxanthin biosynthesis at the late growth phase of H. pluvialis.