Salinity Stress Alerts Genome Stability and Genotoxicity of Ocimum basilicum Cultivars

Abstract

Salinity is an important abiotic stress that greatly influences growth, secondary product content and genotoxicity in plants. Ocimum basilicum L. (family Lamiaceae) produces a volatile oil, which is used in many pharmaceutical industries, but the oil biosynthesis is affected by salt stress. The aim of this study was to evaluate the effect of salinity stress on genome stability and genotoxicity of three basil cultivars (Gigante, Gralissimum and Verde) using comet assays to study the genotoxic impact of salinity stress (0, 50, 100 and 200 mM NaCl) and a semi-quantitative real time polymerase chain reaction to study terpene gene expression. Both analyses revealed considerable genetic effects of salinity stress on the O. basilicum genome, detected by a regular increase in DNA damage and by diversity in the transcript levels of terpene biosynthesis and inhibitor genes. Our findings confirmed that basil plants were affected by NaCl salinity stress and that exposure to 200 mM NaCl resulted in significant DNA damage in the form of tail moment, DNA tail percentage and tail length. The accumulation of linalool synthase enzyme (LS) and hexokinase synthase (HK) gene transcripts was greatly increased in response to salinity, whereas FPPS, GPPS and DXR gene transcription was suppressed in all three basil cultivars. © 2021 Friends Science Publishers