Overexpression of GbWRKY1 positively regulates the Pi starvation response by alteration of auxin sensitivity in Arabidopsis.
Overexpression of a cotton defense-related gene GbWRKY1 in Arabidopsis resulted in modification of the root system by enhanced auxin sensitivity to positively regulate the Pi starvation response. GbWRKY1 was a cloned WRKY transcription factor from Gossypium barbadense, which was firstly identified as a defense-related gene and showed moderate similarity with AtWRKY75 from Arabidopsis thaliana. Overexpression of GbWRKY1 in Arabidopsis resulted in attenuated Pi starvation stress symptoms, including reduced accumulation of anthocyanin and impaired density of lateral roots (LR) in low Pi stress. The study also indicated that overexpression of GbWRKY1 caused plants constitutively exhibited Pi starvation response including increased development of LR, relatively high level of total P and Pi, high expression level of some high-affinity Pi transporters and phosphatases as well as enhanced accumulation of acid phosphatases activity during Pi-sufficient. It was speculated that GbWRKY1 may act as a positive regulator in the Pi starvation response as well as AtWRKY75. GbWRKY1 probably involves in the modulation of Pi homeostasis and participates in the Pi allocation and remobilization but do not accumulate more Pi in Pi-deficient condition, which was different from the fact that AtWRKY75 influenced the Pi status of the plant during Pi deprivation by increasing root surface area and accumulation of more Pi. Otherwise, further study suggested that the overexpression plants were more sensitive to auxin than wild-type and GbWRKY1 may partly influence the LPR1-dependent (low phosphate response 1) Pi starvation signaling pathway and was putatively independent of SUMO E3 ligase SIZ1 and PHR1 (phosphate starvation response 1) in response to Pi starvation.
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China.
Li
L
Xu
Li
L
Jin
Lu
L
Long
Linlin
L
Liu
Xin
X
He
Wei
W
Gao
Longfu
L
Zhu
Xianlong
X
Zhang
D000135:Acid Phosphatase / Q000235:genetics / Q000378:metabolism; D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D000872:Anthocyanins / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003470:Culture Media / Q000378:metabolism; D004789:Enzyme Activation; D018506:Gene Expression Regulation, Plant; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D003368:Gossypium / Q000235:genetics*; D007210:Indoleacetic Acids / Q000378:metabolism / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010710:Phosphates / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D000872:Anthocyanins; D029681:Arabidopsis Proteins; D003470:Culture Media; D007210:Indoleacetic Acids; D010710:Phosphates; D014157:Transcription Factors; C544317:WRKY75 protein, Arabidopsis; D010758:Phosphorus; D000135:Acid Phosphatase