biostudies-literatureUnknown8(12)Littleton ESFlavonoids are abundant specialized metabolites produced by plants for a range of functions, including pigmentation, hormonal signaling, UV protection, and drought tolerance. We previously showed that flavonoids also influence the circadian clock in <i>Arabidopsis</i> Here, we report that the antioxidant properties of dihydroxy B-ring flavonoids are responsible for influencing the amplitude of the core clock gene luciferase reporter, <i>TOC1:LUC</i> We found the elevated amplitude of <i>TOC1:LUC</i> rhythms correlates with the elevated cellular H₂O₂ content of flavonoid-deficient seedlings. Moreover, two different chemical approaches to reduce the accumulation of reactive oxygen species rescued the elevated <i>TOC1:LUC</i> amplitude in flavonoid-deficient seedlings, wLife science alliancee202503328https://www.ebi.ac.uk/biostudies/studies/S-EPMC12479380biostudies-literatureAntioxidant properties of dihydroxy B-ring flavonoids modulate circadian amplitude in &lt;i&gt;Arabidopsis&lt;/i&gt;.PMC12479380Kojima SHildreth SBLittleton ESWinkel BSfalseAntioxidant properties of dihydroxy B-ring flavonoids modulate circadian amplitude in &lt;i&gt;Arabidopsis&lt;/i&gt;.Flavonoids are abundant specialized metabolites produced by plants for a range of functions, including pigmentation, hormonal signaling, UV protection, and drought tolerance. We previously showed that flavonoids also influence the circadian clock in <i>Arabidopsis</i> Here, we report that the antioxidant properties of dihydroxy B-ring flavonoids are responsible for influencing the amplitude of the core clock gene luciferase reporter, <i>TOC1:LUC</i> We found the elevated amplitude of <i>TOC1:LUC</i> rhythms correlates with the elevated cellular H₂O₂ content of flavonoid-deficient seedlings. Moreover, two different chemical approaches to reduce the accumulation of reactive oxygen species rescued the elevated <i>TOC1:LUC</i> amplitude in flavonoid-deficient seedlings, w2025-01-01T00:00:00Z2025 Dec2026-06-03T23:10:24.072Z2026-05-02T03:12:15.951ZS-EPMC124793804102254010.26508/lsa.202503328