Cyclopyrimorate, a highly effective bleaching herbicide for weed control in rice fields, targets homogentisate solanesyltransferase (HST). HST is a downstream enzyme of 4-hydroxyphenylpyruvate dioxygenase in the plastoquinone (PQ) biosynthesis pathway[1][2].
Cyclopyrimorate-dependent bleaching effect on Arabidopsis thaliana is reversed by decyl PQ, suggesting that this symptom is attributable to the inhibition of PQ biosynthesis[1].
[1]. Shino M, et al. In vivo and in vitro evidence for the inhibition of homogentisate solanesyltransferase by cyclopyrimorate. Pest Manag Sci. 2019 Nov 27. [2]. Shino M, et al. Action mechanism of bleaching herbicide cyclopyrimorate, a novel homogentisate solanesyltransferase inhibitor. J Pestic Sci. 2018 Nov 20;43(4):233-239.