Vicia-Micronucleus Test Application for Saline Irrigation Water Risk Assessment.

Dalila Souguir,Mohamed Hachicha,Sourour Mzahma,Hanen Filali,Ronny Berndtsson

doi:10.3390/plants11030462

Abstract

In view of climate change, increasing soil salinity is expected worldwide. It is therefore important to improve prediction ability of plant salinity effects. For this purpose, brackish/saline irrigation water from two areas in central and coastal Tunisia was sampled. The water samples were classified as C3 (EC: 2.01–2.24 dS m−1) and C4 (EC: 3.46–7.00 dS m−1), indicating that the water was questionable and not suitable for irrigation, respectively. The water samples were tested for their genotoxic potential and growth effects on Vicia faba seedlings. Results showed a decrease in mitotic index (MI) and, consequently, growth parameters concomitant to the appearance of micronucleus (MCN) and chromosome aberrations when the water salinity increased. Salt ion concentration had striking influence on genome stability and growth parameters. Pearson correlation underlined the negative connection between most ions in the water inappropriate for irrigation (C4) and MI as well as growth parameters. MI was strongly influenced by Mg2+, Na+, Cl−, and to a less degree Ca2+, K+, and SO42−. Growth parameters were moderately to weakly affected by K+ and Ca2+, respectively. Re-garding MCN, a very strong positive correlation was found for MCN and K+. Despite its short-term application, the Vicia-MCN Test showed a real ability to predict toxicity induced by salt ions confirming that is has a relevant role in hazard identification and risk assessment of salinity effects.

Highlights

During their life cycle, plants face a range of environmental stress and must adjust their growth to the surrounding conditions
We investigated the relationship between water salinity (EC and ionic composition) and plant behavior
High levels of salinity disrupted cell cycle integrity through an inhibition of mitosis accompanied by appearance of abnormal cells supporting micronucleus and chromosome/chromatid aberrations

Summary

Introduction

Plants face a range of environmental stress and must adjust their growth to the surrounding conditions. The quality of water around their roots is an important component that may affect plant development. Salinity limits plant growth and production due to water deficit, ion toxicity, and oxidative burst. Roots are the first barrier to salt ions that may prevent their passage into the plant. When the filtration of salts through the roots is defective, plant growth is dependent on the ability of the plant to keep salt from interfering with its metabolic processes by modulating gene expression and protein activity as well as compartmenting toxic ions. Changes in the root architecture, wall composition, and transport processes are among the main modifications occurring in the roots when salinity is high [7,8]

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