Salicylic acid triggers adaptation cadmium cytogenetic toxicity in roots of Nigella sativa L.

Abstract

C ADMIUM (Cd) is a toxic heavy-metal pollutant in the environment, it is a nonessential element, which strongly inhibits plant growth and development, and causes plant death even at very low concentrations. Root tip cells of Nigella sativa were separately treated with different concentrations (5, 10, 25 and 50ppm) of cadmium for 3, 6, 12 and 24h and the results were recorded. The results showed that all concentrations of cadmium reduced the mitotic index and caused a disturbance in the frequencies of mitotic phases. The treatment with 50ppm of metal for 24h was the most effective in reducing the mitotic activity and inducing the highest percentage of mitotic abnormalities. The different types of abnormalities were irregulatries, bridges, sickness at different phases, disturbed chromosomes or bi nucleated cells, forward and lagging chromosomes. Also, in this study three concentrations of SA (0.01, 0.1 and 0.2mM) for 6 and 12h were used to recover the cytotoxicity of the cadmium treatment (50ppm for 3 and 24h). This Post treatment with SA resulted in increasing MI and significant reduction of chromosomal abnormalities. These results illustrate the ameliorating effect of SA under stress conditions and reveal that SA is effective in alleviating the toxic effects of heavy metals at all applied concentrations.

Acclimation of cadmium-induced genotoxicity and oxidative stress in mung bean seedlings by priming effect of phytohormones and proline

“…Various cytological irregularities were observed during Cd stress in Nigella sativa while post-treatment of SA resulted in a significant increase in MI% with the reduction in chromosomal aberrations. These results are consistent with our findings that observed increase mitotic index and reduced chromosomal aberrations which confirmed ameliorating property of SA under stress [ 67 ]. It was reported that Cd tends to reduce the mitotic activity of root cells thus decrease plant growth by shortening G2 phases and prophase that facilitates the abnormal spindle formation while SA pretreatment increased the mitotic index.…”

Salicylic Acid in Root Growth and Development

“…For example, SA (10 µM) application to chickpea plants exposed to weak or moderate and strong cadmium (Cd) stress increases, restores and partly restores root length, respectively [231]. In some cases, SA's protective effect is due to it reducing stress factor toxicity [232][233][234] (reviewed in [235]). For example, the application of exogenous SA elevates aluminum (Al)-induced citrate efflux from the roots of Cassia tora, which is associated with an increased tolerance of seedlings to Al [44].…”

A Tool Derived from the Vicia faba Micronucleus Assay, to Assess Genotoxicity, Cytotoxicity or Biostimulation of Novel Compounds Used in Agriculture

“…These protective properties of humic or fulvic substances have already been demonstrated by several authors on lettuce against Cd [56] and on radish against Cd, Cu and Zn [57], but not directly on the rate of division in the root apex. The salicylic acid post-treatment of Nigella sativa, exposed to another toxic heavy-metal (cadmium), increases the mitotic index while reducing chromosomal abnormalities [58]. Salicylic acid has a protective action against the genotoxic and toxic effect of heavy metals, as does BHS ® .…”