After oxidative stress the <i>Arabidopsis thaliana</i> plants turn from green into purple indicating a dramatic shift in metabolism, specifically elevated flavonoid biosynthesis involved in oxidative stress protection [6].

Abstract

<p><b>A</b> Plants turns from green to purple under high light and cold temperature treatment. <b>B</b> Van Krevelen diagram of the most abundant <i>m/z</i> values of unstressed (green dots) and 20-day cold stressed (purple dots) Arabidopsis plants. A clear shift of metabolism in the stressed plants is visible.</p