TY - JOUR
T1 - AUX/LAX genes encode a family of auxin influx transporters that perform distinct functions during Arabidopsis development
AU - Péret, Benjamin
AU - Swarup, Kamal
AU - Ferguson, Alison
AU - Seth, Malvika
AU - Yang, Yaodong
AU - Dhondt, Stijn
AU - James, Nicholas
AU - Casimiro, Ilda
AU - Perry, Paula
AU - Syed, Adnan
AU - Yang, Haibing
AU - Reemmer, Jesica
AU - Venison, Edward
AU - Howells, Caroline
AU - Perez-Amador, Miguel A
AU - Yun, Jeonga
AU - Alonso, Jose
AU - Beemster, Gerrit T S
AU - Laplaze, Laurent
AU - Murphy, Angus
AU - Bennett, Malcolm J
AU - Nielsen, Erik
AU - Swarup, Ranjan
PY - 2012
Y1 - 2012
N2 - Auxin transport, which is mediated by specialized influx and efflux carriers, plays a major role in many aspects of plant growth and development. AUXIN1 (AUX1) has been demonstrated to encode a high-affinity auxin influx carrier. In Arabidopsis thaliana, AUX1 belongs to a small multigene family comprising four highly conserved genes (i.e., AUX1 and LIKE AUX1 [LAX] genes LAX1, LAX2, and LAX3). We report that all four members of this AUX/LAX family display auxin uptake functions. Despite the conservation of their biochemical function, AUX1, LAX1, and LAX3 have been described to regulate distinct auxin-dependent developmental processes. Here, we report that LAX2 regulates vascular patterning in cotyledons. We also describe how regulatory and coding sequences of AUX/LAX genes have undergone subfunctionalization based on their distinct patterns of spatial expression and the inability of LAX sequences to rescue aux1 mutant phenotypes, respectively. Despite their high sequence similarity at the protein level, transgenic studies reveal that LAX proteins are not correctly targeted in the AUX1 expression domain. Domain swapping studies suggest that the N-terminal half of AUX1 is essential for correct LAX localization. We conclude that Arabidopsis AUX/LAX genes encode a family of auxin influx transporters that perform distinct developmental functions and have evolved distinct regulatory mechanisms.
AB - Auxin transport, which is mediated by specialized influx and efflux carriers, plays a major role in many aspects of plant growth and development. AUXIN1 (AUX1) has been demonstrated to encode a high-affinity auxin influx carrier. In Arabidopsis thaliana, AUX1 belongs to a small multigene family comprising four highly conserved genes (i.e., AUX1 and LIKE AUX1 [LAX] genes LAX1, LAX2, and LAX3). We report that all four members of this AUX/LAX family display auxin uptake functions. Despite the conservation of their biochemical function, AUX1, LAX1, and LAX3 have been described to regulate distinct auxin-dependent developmental processes. Here, we report that LAX2 regulates vascular patterning in cotyledons. We also describe how regulatory and coding sequences of AUX/LAX genes have undergone subfunctionalization based on their distinct patterns of spatial expression and the inability of LAX sequences to rescue aux1 mutant phenotypes, respectively. Despite their high sequence similarity at the protein level, transgenic studies reveal that LAX proteins are not correctly targeted in the AUX1 expression domain. Domain swapping studies suggest that the N-terminal half of AUX1 is essential for correct LAX localization. We conclude that Arabidopsis AUX/LAX genes encode a family of auxin influx transporters that perform distinct developmental functions and have evolved distinct regulatory mechanisms.
U2 - 10.1105/tpc.112.097766
DO - 10.1105/tpc.112.097766
M3 - Article
C2 - 22773749
SN - 1040-4651
VL - 24
SP - 2874
EP - 2885
JO - The Plant Cell
JF - The Plant Cell
IS - 7
ER -