Nitric oxide mediates strigolactone signaling in auxin and ethylene-sensitive lateral root formation in sunflower seedlings

摘要: Strigolactones (SLs) play significant role in shaping root architecture whereby auxin-SL crosstalk has been observed SL-mediated responses of primary elongation, lateral formation and adventitious (AR) initiation. Whereas GR24 (a synthetic strigolactone) inhibits LR AR formation, the effect SL biosynthesis inhibitor (fluridone) is just opposite (root proliferation). Naphthylphthalamic acid (NPA) leads to proliferation but completely development. The diffusive distribution PIN1 provascular cells differentiating zone roots response GR24, fluridone or NPA treatments further indicates involvement localized auxin accumulation development responses. Inhibition by treatment coincides with inhibition ACC synthase activity. Profuse correlates enhanced [Ca2+]cyt apical region zones LR, indicating a critical [Ca2+] coordinated action auxins, ethylene SLs. Significant enhancement carotenoid cleavage dioxygenase (CCD) activity (enzyme responsible for biosynthesis) tissue homogenates presence cPTIO (NO scavenger) endogenous NO as negative modulator CCD Differences spatial highlight SL-modulated morphogenesis sunflower seedlings. Present work provides new report on modulation through nitric oxide during