AUTHOR=Ausma Ties , De Kok Luit J. 

TITLE=Atmospheric H2S: Impact on Plant Functioning

JOURNAL=Frontiers in Plant Science

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00743

DOI=10.3389/fpls.2019.00743

ISSN=1664-462X

ABSTRACT=<p>Hydrogen sulfide (H<sub>2</sub>S) is an air pollutant present at high levels in various regions. Plants actively take up H<sub>2</sub>S via the foliage, though the impact of the gas on the physiological functioning of plants is paradoxical. Whereas elevated H<sub>2</sub>S levels may be phytotoxic, H<sub>2</sub>S levels realistic for polluted areas can also significantly contribute to the sulfur requirement of the vegetation. Plants can even grow with H<sub>2</sub>S as sole sulfur source. There is no relation between the rate of H<sub>2</sub>S metabolism and the H<sub>2</sub>S susceptibility of a plant, which suggests that the metabolism of H<sub>2</sub>S does not contribute to the detoxification of absorbed sulfide. By contrast, there may be a strong relation between the rate of H<sub>2</sub>S metabolism and the rate of sulfate metabolism: foliar H<sub>2</sub>S absorbance may downregulate the metabolism of sulfate, taken up by the root. Studies with plants from the <italic>Brassica</italic> genus clarified the background of this downregulation. Simultaneously, these studies illustrated that H<sub>2</sub>S fumigation may be a useful tool for obtaining insight in the regulation of sulfur homeostasis and the (signal) functions of sulfur-containing compounds in plants.</p>