Abstract
This study investigates the response of metallicolous (M) and nonmetallicolous (NM) ecotypes of Dianthus carthusianorum L. to chronic multi-metal and acute Zn stress. Plants were cultivated on the Zn-Pb waste heap substrate and under Zn excess in hydroponics. Growth parameters as well as accumulation of organic acids and thiol peptides were determined as a function of metal accumulation. When grown on the metalliferous substrate, the M plants showed less phytotoxicity symptoms, lower foliar metal (Zn, Pb, Cd) accumulation, higher malate and citrate but lower glutathione content than the NM plants. When exposed to Zn excess in hydroponics, the M ecotype was also more tolerant but accumulated more Zn in comparison with the NM ecotype, accompanied by greater malate and citrate concentrations in the shoots, which were however not affected by increasing Zn doses. No phytochelatins were detected under any experimental conditions. Both constitutive and adaptive tolerance was found in D. carthusianorum. Under chronic metal stress, enhanced tolerance results from restricted metal uptake to the shoots and probably from detoxification by organic acids; however, under acute Zn stress it is not related to diminished metal uptake or organic acids. Glutathione and phytochelatins are not implicated in adaptive metal tolerance.
Highlights
Zinc (Zn) is widespread in the environment, due to both natural and anthropogenic sources (Broadley et al 2007; Sinclair and Krämer 2012)
The total Zn concentrations in soils usually range from 10 to 300 mg kg-1 with an average of approximately 50–66 mg kg-1 (Broadley et al 2007; Kabata-Pendias and Mukherjee 2007). They can reach thousands of mg kg-1 in severely Zn-contaminated soils, and are high in waste deposits left after Zn ore mining and smelting. Zinc concentrations in such deposits in southern Poland are as high as 7.5–17.2 % of dry substrate matter, and are accompanied by substantially elevated concentrations of lead (Pb) (9,190–22,265 mg kg-1) and cadmium (Cd) (558–1,464 mg kg-1) (Wójcik et al 2014)
We demonstrated that the elevated Pb and Cd tolerance of the metallicolous ecotype of D. carthusianorum was not related to increased production of thiol peptides and organic acids (Wójcik and Tukiendorf 2014; Wójcik et al 2015)
Summary
Zinc (Zn) is widespread in the environment, due to both natural and anthropogenic sources (Broadley et al 2007; Sinclair and Krämer 2012). The total Zn concentrations in soils usually range from 10 to 300 mg kg-1 with an average of approximately 50–66 mg kg-1 (Broadley et al 2007; Kabata-Pendias and Mukherjee 2007). They can reach thousands of mg kg-1 in severely Zn-contaminated soils, and are high in waste deposits left after Zn ore mining and smelting. Some pseudometallophytes may exhibit constitutive tolerance, i.e., inherent tolerance to metals present in all populations of a species, even growing without any selective pressure in uncontaminated habitats (Bert et al 2000)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
