Tobacco and zinnia can thrive in polluted land

In a new study from Ural Federal University, experts have demonstrated that flowers and tobacco can thrive on polluted land. These plants can adapt to copper in the soil by limiting the accumulation of the metal to the stem and leaves. 

“Plants of the Asteraceae and Nightshade families, namely zinnia and tobacco, are copper-exclusive, their root system performs the function of copper accumulation,” explained study co-author Anastasia Tugbaeva. “Biotechnologies for maintaining and restoring components of natural and transformed biosystems”, UrFU. 

“Using zinnia as an example, we have shown for the first time that it can grow in copper-contaminated soils and even flower faster than in pure soils. That is, it can be used for landscaping areas, it will grow well. Tobacco, an important agricultural crop and useful fertilizer, also adapted to long-term exposure to copper in our experiments and grew comparable to control plants, despite the high content of copper in the substrate.”

For the investigation, the scientists recreated realistic levels of humidity and temperature0. They tested the effect of various concentrations of copper sulfate on growth, and analyzed various physiological characteristics of the plants.

“We conducted experiments for 20, 40, 60 days and used substrates in which the content of copper could even exceed its content in urban soils,” said Tugbaeva. “Under the influence of copper in the root and stem of plants, the expression of five genes responsible for the synthesis of phenolic compounds and lignin is enhanced. Lignin is one of the components of the plant cell wall, which makes it stronger. It is lignin that is the mechanism of plant adaptation, which limits the transfer of metals from the cell wall and the effects of metals on the intracellular structure of the plant.”

The study is published in the journal Horticulturae.

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By Chrissy Sexton, Earth.com Staff Writer