TY - JOUR
T1 - Halotropism requires Phospholipase Dζ1-mediated modulation of cellular polarity of auxin transport carriers
AU - Korver, Ruud A
AU - van den Berg, Thea
AU - Meyer, A Jessica
AU - Galvan-Ampudia, Carlos S
AU - Ten Tusscher, Kirsten H W J
AU - Testerink, Christa
N1 - This article is protected by copyright. All rights reserved.
PY - 2020/1
Y1 - 2020/1
N2 - Endocytosis and re-localization of auxin carriers represent important mechanisms for adaptive plant growth- and developmental responses. Both root gravitropism and halotropism have been shown to be dependent on re-localization of auxin transporters. Following their homology to mammalian phospholipase Ds (PLDs), plant PLD ζ-type enzymes are likely candidates to regulate auxin-carrier endocytosis. We investigated root tropic responses for an Arabidopsis pldζ1-KO mutant, and its effect on the dynamics of two auxin transporters during salt stress, i.e. PIN2 and AUX1. We found altered root growth, halotropic- and gravitropic responses in absence of PLDζ1, and report a role for PLDζ1 in the polar localization of PIN2. Additionally, irrespective of the genetic background, salt stress induced changes in AUX1 polarity. Utilizing our previous computational model, we found that these novel salt induced-AUX1 changes contribute to halotropic auxin asymmetry. We also report the formation of 'Osmotic Stress-Induced Membrane Structures', or OSIMS. These large membrane structures are formed at the plasma membrane shortly after NaCl or sorbitol treatment, and have a prolonged presence in a pldζ1 mutant. Taken together, these results show a crucial role for PLDζ1 in both ionic and osmotic stress-induced auxin carrier dynamics during salt stress.
AB - Endocytosis and re-localization of auxin carriers represent important mechanisms for adaptive plant growth- and developmental responses. Both root gravitropism and halotropism have been shown to be dependent on re-localization of auxin transporters. Following their homology to mammalian phospholipase Ds (PLDs), plant PLD ζ-type enzymes are likely candidates to regulate auxin-carrier endocytosis. We investigated root tropic responses for an Arabidopsis pldζ1-KO mutant, and its effect on the dynamics of two auxin transporters during salt stress, i.e. PIN2 and AUX1. We found altered root growth, halotropic- and gravitropic responses in absence of PLDζ1, and report a role for PLDζ1 in the polar localization of PIN2. Additionally, irrespective of the genetic background, salt stress induced changes in AUX1 polarity. Utilizing our previous computational model, we found that these novel salt induced-AUX1 changes contribute to halotropic auxin asymmetry. We also report the formation of 'Osmotic Stress-Induced Membrane Structures', or OSIMS. These large membrane structures are formed at the plasma membrane shortly after NaCl or sorbitol treatment, and have a prolonged presence in a pldζ1 mutant. Taken together, these results show a crucial role for PLDζ1 in both ionic and osmotic stress-induced auxin carrier dynamics during salt stress.
U2 - 10.1111/pce.13646
DO - 10.1111/pce.13646
M3 - Article
C2 - 31430837
SN - 0140-7791
VL - 43
SP - 143
EP - 158
JO - Plant, Cell and Environment
JF - Plant, Cell and Environment
IS - 1
ER -