Characterization of non-target-site mechanisms in imidazolinone resistant sunflower (Helianthus annuus L.)

Imisun sunflowers are imidazolinone resistant cultivars in which the two primary mechanisms of herbicide resistance coexist: (i) mutation in herbicide target-site (target-site resistance) and (ii) non-target-site resistance (NTSR). NTSR can emerge from a constitutive up-regulation of resistance genes or it can appear only after herbicide treatment. The objective of this study was to characterize NTSR in Imisun sunflower in response to imazethapyr using RNA-Seq and to determine whether these mechanisms are constitutive or herbicide-induced.