Interactive effect of potassium and cadmium on growth, root morphology and chlorophyll a fluorescence in tomato plant

Abstract

A hydroponic experiment was conducted to evaluate the role of potassium (K) in tomato plant growth exposed to cadmium (Cd) stress. In this work, the effects of three potassium nutrition regimes (155, 232 and 310 ppm of K) combined with Cd at different levels (0, 12 and 25 µM of CdCl2) on chlorophyll content index, root and shoot dry weights, root morphology, chlorophyll a fluorescence and translocation factor were analyzed. The results showed a negative effect of cadmium, at different concentrations, on all these parameters. However, optimization of K nutrition has shown promising results by limiting the negative effect of Cd. A positive effect of the high concentration of K (310 ppm) was observed on leaf chlorophyll content and chlorophyll a fluorescence compared to 232 and 155 ppm under Cd stress. K supply improved the electron transport at PSI side indicated by the increase in the amplitude of the I–P phase of OJIP transient. Also, K at a concentration of 310 ppm significantly reduced Cd translocation from root to shoot and improved root and shoot growth parameters in the presence of Cd. K supplementation can reduce the negative effect of Cd by improving photosynthesis and promoting chlorophyll synthesis. The optimization of nutrients composition and concentration might be a good strategy to reduce the impact of Cd on plant growth and physiology.

Slaked lime improves growth, antioxidant capacity and reduces Cd accumulation of peanut (Arachis hypogaea L.) under Cd stress

“…Chlorophyll content is an important index for indicating environmental stress in plants and reflects plant tolerance. In addition, chlorophyll content has been considered to be a reliable stress-induced biomarker to assess heavy metal-induced phytotoxicity in a variety of farmland crops 61 .…”

“…Essential nutrients, mainly K, can promote the activity of these enzymes when the crop is under metal stress. K aids in the transportation of water and nutrition via the xylem and may further promote the involvement of many other latent enzymes 61 . Therefore, with the application of slaked lime, supplementing with K increased H 2 O 2 detoxification due to increased SOD and CAT activity 50 .…”

Photosynthetic apparatus performance and anatomical modulations of Alcantarea imperialis (Bromeliaceae) exposed to selenium during in vitro growth

“…4A) indicated that this element affected the process involving the trapping of the exciton to the reduction of PQ and those plants could maintain the maximum PQ reduction rate (Adamski et al 2011). VOI ≥ 1 is related to the I-P phase and reveals the changes in the electron flux from the plastoquinol (PQH2) to the end electron acceptors on the PSI acceptor side (Yusuf et al 2010, Braga et al 2020, Naciri et al 2021). The higher amplitudes observed through the normalization between the O-I steps (VOI ≥ 1.0) in Se-treated plants (Fig.…”

Arbuscular Mycorrhizal Fungi and Dry Raw Garlic Stalk Amendment Alleviate Continuous Monocropping Growth and Photosynthetic Declines in Eggplant by Bolstering Its Antioxidant System and Accumulation of Osmolytes and Secondary Metabolites

“…These various biotic and abiotic stresses cause changes in the crop plant by disrupting its balance of reactive oxygen species (ROS). Overproduction of ROS impairs membrane integrity and cellular function by interfering with photosynthesis, mineral absorption, and assimilation ( Naciri et al, 2021 ). To mitigate elevated ROS production and metabolic protection, plants will often upregulate their antioxidant system and accumulate more osmolytes ( Ghani et al, 2019a ; Ahanger et al, 2021 ).…”