Akademik Veri Yönetim Sistemi
4th International Congress on Plant Biology, Denizli, Türkiye, 3 Eylül - 06 Ekim 2025, ss.78, (Özet Bildiri)
Nickel contamination is a widespread environmental issue that poses a serious threat to
ecosystems and organisms. Elevated nickel levels in agricultural soils can reduce crop yields
and bioaccumulate through the food chain, causing significant health problems in humans.
Phytoremediation, a method that exploits plants’ ability to accumulate and tolerate various
contaminants, is used to reclaim and remediate these sites. In this study, two plant growth-
promoting bacteria, Streptomyces pseudovenezuelae and Streptomyces griseorubiginosus,
isolated from the nickel-hyperaccumulator Centaurea ensiformis P.H. Davis, were inoculated
into Carthamus tinctorius L. cv. Yenice (Safflower) to improve its nickel tolerance and
phytoremediation capacity, based on their effects on the plant’s nickel accumulation,
morphological traits, and physiological responses. Plants were grown hydroponically in
Hoagland’s nutrient solution in a controlled environment (25°C, 16/8 h light/dark cycle, 250–
350 µmol·m⁻²·s⁻¹ light intensity, 45–55% humidity) without nickel for 14 days, after which
0.75 mM nickel was applied for 7 days to the stress groups. According to results, nickel
accumulates predominantly in the roots of safflower plants. Moreover, nickel toxicity decreased
biomass in both roots and shoots, reduced pigment contents, and impaired photosynthetic
energy flow, based on chlorophyll a fluorescence kinetics measurements. While the root
concentration of nickel remained consistent across all nickel-treated groups, the shoot
concentration of nickel increased by 29.9% with S. griseorubiginosus and decreased by 21.2%
with S. pseudovenezuelae. Root and shoot dry biomass, along with chlorophyll a and b content,
were increased by 33%, 61%, 94%, and 108%, respectively, with S. griseorubiginosus
inoculation, whereas S. pseudovenezuelae did not cause any significant changes in these
parameters. Additionally, S. griseorubiginosus improved photosynthetic efficiency. In
summary, due to increased nickel accumulation and translocation in plants, S.
pseudovenezuelae is a promising enhancer for phytoremediation applications, and S.
griseorubiginosus can be suitable for safe safflower cultivation in nickel-contaminated areas.
Keywords: Carthamus tinctorius L., Chlorophyll a fluorescence, Heavy metal, Streptomyces
Acknowledgments: This study was supported by TÜBİTAK under project number 222Z011.