Arabidopsis ASA1 is important for jasmonate-mediated regulation of auxin biosynthesis and transport during lateral root formation.
Plant roots show an impressive degree of plasticity in adapting their branching patterns to ever-changing growth conditions. An important mechanism underlying this adaptation ability is the interaction between hormonal and developmental signals. Here, we analyze the interaction of jasmonate with auxin to regulate lateral root (LR) formation through characterization of an Arabidopsis thaliana mutant, jasmonate-induced defective lateral root1 (jdl1/asa1-1). We demonstrate that, whereas exogenous jasmonate promotes LR formation in wild-type plants, it represses LR formation in jdl1/asa1-1. JDL1 encodes the auxin biosynthetic gene ANTHRANILATE SYNTHASE alpha1 (ASA1), which is required for jasmonate-induced auxin biosynthesis. Jasmonate elevates local auxin accumulation in the basal meristem of wild-type roots but reduces local auxin accumulation in the basal meristem of mutant roots, suggesting that, in addition to activating ASA1-dependent auxin biosynthesis, jasmonate also affects auxin transport. Indeed, jasmonate modifies the expression of auxin transport genes in an ASA1-dependent manner. We further provide evidence showing that the action mechanism of jasmonate to regulate LR formation through ASA1 differs from that of ethylene. Our results highlight the importance of ASA1 in jasmonate-induced auxin biosynthesis and reveal a role for jasmonate in the attenuation of auxin transport in the root and the fine-tuning of local auxin distribution in the root basal meristem.
Sun
Jiaqiang
J
State Key Laboratory of Plant Genomics, National Centre for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Xu
Yingxiu
Y
Ye
Songqing
S
Jiang
Hongling
H
Chen
Qian
Q
Liu
Fang
F
Zhou
Wenkun
W
Chen
Rong
R
Li
Xugang
X
Tietz
Olaf
O
Wu
Xiaoyan
X
Cohen
Jerry D
JD
Palme
Klaus
K
Li
Chuanyou
C
D000085:Acetates / Q000378:metabolism / Q000494:pharmacology*; D000878:Anthranilate Synthase / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D017360:Arabidopsis / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D001692:Biological Transport / Q000187:drug effects; D003517:Cyclopentanes / Q000378:metabolism / Q000494:pharmacology*; D005030:Ethylenes / Q000494:pharmacology; D007210:Indoleacetic Acids / Q000378:metabolism*; D009154:Mutation; D054883:Oxylipins / Q000378:metabolism / Q000494:pharmacology*; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
D000085:Acetates; D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D005030:Ethylenes; D007210:Indoleacetic Acids; D054883:Oxylipins; C072239:methyl jasmonate; C036216:ethylene; C543688:ASA1 protein, Arabidopsis; D000878:Anthranilate Synthase