Auxin and auxin-mediated signaling pathways are known to regulate lateral root development.Although exocytic vesicle trafficking plays an important role in recycling the PIN-FORMED(PIN)auxin efflux carriers and in pol...Auxin and auxin-mediated signaling pathways are known to regulate lateral root development.Although exocytic vesicle trafficking plays an important role in recycling the PIN-FORMED(PIN)auxin efflux carriers and in polar auxin transport during lateral root formation,the mechanistic details of these processes are not well understood.Here,we demonstrate that BYPASS1-LIKE(B1 L)regulates lateral root initiation via exocytic vesicular trafficking-mediated PIN recycling in Arabidopsis thaliana.b1 l mutants contained significantly more lateral roots than the wild type,primarily due to increased lateral root primordium initiation.Furthermore,the auxin signal was stronger in stage I lateral root primordia of b1 l than in those of the wild type.Treatment with exogenous auxin and an auxin transport inhibitor indicated that the lateral root phenotype of b1 l could be attributed to higher auxin levels and that B1 L regulates auxin efflux.Indeed,compared to the wild type,C-terminally green fluorescent protein-tagged PIN1 and PIN3 accumulated at higher levels in b1 l lateral root primordia.B1 L interacted with the exocyst,and b1 l showed defective PIN exocytosis.These observations indicate that B1 L interacts with the exocyst to regulate PIN-mediated polar auxin transport and lateral root initiation in Arabidopsis.展开更多
基金supported by the Key Program National Natural Science Foundation of China(41830321)the National Natural Science Foundation of China(31770432,32071482)the Fundamental Research Funds for the Central Universities(lzujbky-2020-31)。
文摘Auxin and auxin-mediated signaling pathways are known to regulate lateral root development.Although exocytic vesicle trafficking plays an important role in recycling the PIN-FORMED(PIN)auxin efflux carriers and in polar auxin transport during lateral root formation,the mechanistic details of these processes are not well understood.Here,we demonstrate that BYPASS1-LIKE(B1 L)regulates lateral root initiation via exocytic vesicular trafficking-mediated PIN recycling in Arabidopsis thaliana.b1 l mutants contained significantly more lateral roots than the wild type,primarily due to increased lateral root primordium initiation.Furthermore,the auxin signal was stronger in stage I lateral root primordia of b1 l than in those of the wild type.Treatment with exogenous auxin and an auxin transport inhibitor indicated that the lateral root phenotype of b1 l could be attributed to higher auxin levels and that B1 L regulates auxin efflux.Indeed,compared to the wild type,C-terminally green fluorescent protein-tagged PIN1 and PIN3 accumulated at higher levels in b1 l lateral root primordia.B1 L interacted with the exocyst,and b1 l showed defective PIN exocytosis.These observations indicate that B1 L interacts with the exocyst to regulate PIN-mediated polar auxin transport and lateral root initiation in Arabidopsis.
