Biologia, vol.78, no.4, pp.1119-1127, 2023 (SCI-Expanded)
Nanoparticles (NPs) of CaO (Ca2+) are significant components that act as signal transductors in plants' adaptive and developmental processes. The responses of two different landrace varieties (Uzuntekne and Barış) of Onobrychis viciifolia to the mannitol stress of CaO NPs were investigated in this study. Their response to various morphological and physiological processes under in vitro conditions was analyzed in this study. Two Onobrychis viciifolia cultivars were used in the presence of 50 and 150 mM of mannitol, including 0.5 ppm and 1.5 ppm Ca2+ nanoparticles. The effects of CaO NPs were induced by mannitol which, root, stem, leaf development, MDA, H2O2, chlorophyll content, gene expression, and SEM images were determined for the in vitro seedlings. CaO remarkably increased the activation of growth parameters in two tested cultivars. Synergistic treatments of NPs affected the seedlings more than the sole treatments. In terms of MDA, H2O2, and chlorophyll content, it was found that the Ca2+ NPs treatment was significant, and it exhibited a high level related to the resistance degrees of cultivars. The chlorophyll content demonstrated a reducing trend in response to increasing concentrations of mannitol. However, there were significant differences between the control group samples and the CaO mannitol treatment samples in response to H2O2 and MDA. The gene expression analysis revealed that MtdDehyd and MtRD2 genes were expressed at various degrees in the seedlings of two Onobyrchis cultivars subjected to drought treatments. Improving resistance to drought stress in tested cultivars can be regulated by expressing MtdDehyd and MtRD2 genes in vitro conditions. SEM images in stomatal structures of cells were easily changed in the mannitol treatment samples in the presence of CaO, and a different stress severity level was detected in their control treatments.