Physiological, photochemical, and antioxidant responses of wild and cultivated Carthamus species exposed to nickel toxicity and evaluation of their usage potential in phytoremediation

Abstract

The responses of growth, photochemical and antioxidant defence of sa ower species (Carthamus oxyacantha M. Bieb. and Carthamus tinctorius L. exposed to nickel (Ni) toxicity were investigated in the study. Fourteen-day-old seedlings were treated with excessive Ni levels [control, 0.50, 0.75 and 1.00 mM] for 7 days. The results of chlorophyll a uorescence indicated that toxic nickel exposure led to changes in speci c, phenomenological energy uxes and quantum yields in thylakoid membranes, and activities of donor and acceptor sides of photosystems. These changes resulted in a signi cant decrease in the photosynthetic performance of the species, but these negative effects of Ni were not in a level to destroy the functionality of the photosystems. At the same time, toxic Ni affected membrane integrity and the amount of photosynthetic pigments in the antenna and active reaction centers. Additionally, the accumulation of Ni was higher in roots than in stem and leaves for both species. Depending on Ni accumulation, a signi cant reduction in dry biomass of root and shoot was observed in both species.Two species could probably withstand deleterious Ni toxicity with better upregulating own protective defence systems such as antioxidant enzymes. Among of them, SOD and POD activities were increased with increasing Ni concentrations. The POD activities of both species were most prominent and consistently increased in toxic Ni levels and may be protected them from damaging effect of H 2 O 2 . When all results are evaluated as a whole, Carthamus species produced similar responses to toxicity and also both species have Bioconcentration (BCF) and Bioaccumulation factors (BF) > 1 and Translocation factor (TF) < 1 under Ni toxicity may be regarded a good indication of Ni tolerance. Consequently, it is possible to use the Carthamus species in the remediation (phytostabilization) of soils contaminated with nickel, because of their roots accumulating more nickel.

Nickel toxicity to safflower seed germination and seedling morpho-anatomy

“…1-a). Although some of Ni are transported to the upper part of the plant, Ni mainly accumulates in the roots of sa ower (Baran and Ekmekçi, 2022). Therefore, the dry weight of the roots was expected to be more affected by Ni than the dry weight of the shoots, and these results are in concordance with our previous study (Baran and Ekmekçi, 2022).…”

“…For morpho-anatomic and physiologic tests, following the method in our previous study (Baran and Ekmekçi, 2022), sa ower seedlings were transferred to a hydroponic culture containing Hoagland's nutrient solution after germination and were grown for 10 days in a control condition. On the 10th day of the growth, Ni stress was treated by applying Hoagland's nutrient solution containing 0.75 mM Ni for the next 7 days.…”

The photochemical and antioxidant defense strategies of two maize genotypes exposed to zinc toxicity at the seedling stage

“…Various studies have exhibited that the increases in POD and Asada-Halliwell pathway enzymes (APX, GR etc.) activities in plants were detoxified damaging effects of metal toxicity (Ekmekçi et al 2008;Mukhopadhyay et al 2013;Tiecher et al 2017;Baran & Ekmekçi 2022).…”