Variable accumulation of cadmium in flax (Linum usitatissimum L.)

Petra Ranušová,Monika Bardáčová,Zuzana Gerši,Miroslav Horník,Mária Pavlovičová,Ildikó Matušíková

doi:10.36547/nbc.v19i1.579

Abstract

Given the potential use of flax in metal-contaminated soil remediation programs, the uptake and accumulation of cadmium was studied in five varieties of flax (Linum usitatissimum L.) including var. Belinka, Escalina, Jitka, Marina and Krasnoder. Early stage plants in hydroponics were exposed to Cd to assess their tolerance by means of growth parameters and content of photosynthetic pigments. All varieties exerted tolerance indexes in the range of 63 – 89 %, while oxidative stress was not detected in either variety. Chitinase enzymes were analyzed in leaf protein extracts since activities of these enzymes have previously been correlated with plant tolerance to Cd. However, total enzyme activities remained unchanged in presence of Cd in all flax varieties. A more detailed analysis of these enzymes identified up to 3 chitinase isoforms upon separation of leaf protein extracts in polyacrylamide gels, and their quantification confirmed responsiveness to Cd for each of them. The obtained data were interpreted in light of metal uptake rate, which we measured using gammaspectrometry in growth media spiked with 109Cd and in the plant tissue. The variety Jitka showed the most sensitive to Cd and accumulating fast and the highest amounts of metal. In contrast, the variety Belinka appeared most tolerant, accumulating the least Cd in a slow rate. Activation of chitinase isoforms correlated with more sensitive varieties and suggests activation of general defense mechanisms. The obtained data suggest the variety Jitka as most promising for phytoremediation programs and the var. Belinka as the most suitable when avoidance of potential health risk is of interest.

Highlights

Crop plants grown in heavy metal (HM) contaminated areas represent a considerable health risk after entering the food chain (Chen et al 2016a)
The ~ 65 kDa isoform was detectable only in control plants of the Belinka and Krasnoder varieties, but due to cadmium its activity fell below the level of detectability (Fig. 4D)
The obtained results confirmed the high responsiveness of flax chitinases to the given concentration of cadmium, but we did not notice any change in their profiles (Békésiová et al 2008), nor differences in profiles between varieties (Mészáros et al 2013)

Summary

Introduction

Crop plants grown in heavy metal (HM) contaminated areas represent a considerable health risk after entering the food chain (Chen et al 2016a). The tolerance indexes expressed based of FW data ranged between 63 – 85 % (Fig. 1A), to previous studies with adult plants of some other flax varieties (Shi and Cai 2009; Bjelková et al 2011; Douchiche et al 2012). Most tolerant plants to Cd appeared here the variety Krasnoder, the growth of which was unaffected in regard of shoot length (Fig. 1B).

Results

Conclusion