Independent variation in copper tolerance and copper accumulation among crop species and varieties

• Published in: Plant physiology and biochemistry Vol. 156; pp. 538 - 551
• Main Authors: Novello, Nicola, Ferfuia, Claudio, Pasković, Igor, Fabris, Andrea, Baldini, Mario, Schat, Henk, Pošćić, Filip
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01-11-2020
• Subjects: Cellulose; Copper - metabolism; Copper - toxicity; Crops; Crops, Agricultural - physiology; Fatty acids; Lignin; Manganese; Nutrient status; Plant Roots - growth & development; Plant Roots - metabolism; Soil Pollutants - toxicity; Zinc; Lignin; Nutrient status; Crops; Cellulose; EC50; Fatty acids; Zinc; Manganese
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2020.09.039

Copper (Cu) locally contaminates soils and might negatively affect growth and yield of crops. A better understanding of plant copper tolerance and accumulation is needed in order to breed more Cu-tolerant or Cu-efficient crops. Cu tolerance was evaluated in different varieties of seven species (Brassica carinata, B. juncea, B. napus, Cynara cardunculus, Helianthus annuus, Nicotiana tabacum and Raphanus sativus) exposed to a series of CuSO4 concentrations (0.1–8 μM CuSO4) in the nutrient solution. Plants were further exposed to 0.1 μM CuSO4 and to their variety-specific concentrations that reduced root growth to 50% of the maximum rate (EC50). Among all the varieties of all the species the EC50 varied from 0.7 up to 3.1 μM Cu. B. carinata was significantly more Cu-sensitive than the other species, which were not significantly different among each other, and B. carinata and H. annuus accommodated significant intra-specific, inter-varietal variation. There were significant differences between species in Cu uptake efficiency and nutrient status. When under EC50 exposure, all the Brassicaceae, except B. carinata, maintained low Cu concentrations in shoots, whereas the other species and B. carinata exhibited significantly increased shoot Cu concentrations, compared to the control. There was no apparent relationship between Cu tolerance and Cu accumulation in roots and shoots, suggesting that the observed variation in tolerance, both between and within species, is not explained by differential exclusion capacity. Discriminant analysis and treatment comparisons suggest possible contribution of lignin, saturated fatty acids, manganese (Mn) and zinc (Zn) in tolerance to high Cu concentrations in shoot.
[Display omitted]
•Cu tolerance and accumulation was evaluated in different varieties and species.•Significant differences between species in Cu uptake efficiency were found.•The variation in tolerance was not explained by differential Cu exclusion capacity.•Nutrient status was differently affected in different species.•Lignin, saturated fatty acids, Mn and Zn may be involved in shoot tolerance to high Cu concentrations.