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Auxin response factor (Os ARF 12), a novel regulator for phosphate homeostasis in rice ( Oryza sativa )
Author(s) -
Wang SuiKang,
Zhang SaiNa,
Sun ChenDong,
Xu YanXia,
Chen Yue,
Yu ChenLiang,
Qian Qian,
Jiang DeAn,
Qi YanHua
Publication year - 2014
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.12499
Subject(s) - auxin , mutant , transcription factor , myb , biology , oryza sativa , homeostasis , phosphate , pi , microbiology and biotechnology , biochemistry , response regulator , chemistry , gene
Summary Phosphorus (P) is crucial nutrient element for crop growth and development. However, the network pathway regulating homeostasis of phosphate (Pi) in crops has many molecular breeding unknowns. Here, we report that an auxin response factor, Os ARF 12 , functions in Pi homeostasis. Measurement of element content, quantitative reverse transcription polymerase chain reaction analysis and acid phosphatases (APases) activity assay showed that the osarf12 mutant and osarf12/25 double mutant with P‐intoxicated phenotypes had higher P concentrations, up‐regulation of the Pi transporter encoding genes and increased APase activity under Pi‐sufficient/‐deficient (+Pi/−Pi, 0.32/0 mM NaH 2 PO 4 ) conditions. Transcript analysis revealed that Pi‐responsive genes – Phosphate starvation ( Os IPS ) 1 and Os IPS 2 , SYG 1/Pho81/ XPR 1( Os SPX 1 ), Sulfoquinovosyldiacylglycerol 2 ( Os SQD 2 ), R2R3 MYB transcription factor ( Os MYB 2P‐1 ) and Transport Inhibitor Response1 ( Os TIR 1 ) – were more abundant in the osarf12 and osarf12/25 mutants under +Pi/−Pi conditions. Knockout of Os ARF 12 also influenced the transcript abundances of the Os PHR 2 gene and its downstream components, such as OsMiR399j , Os PHO 2 , OsMiR827 , Os SPX ‐ MFS 1 and Os SPX ‐ MFS 2 . Results from –Pi/1‐naphthylphthalamic acid ( NPA ) treatments, and auxin reporter DR 5:: GUS staining suggest that root system alteration and Pi‐induced auxin response were at least partially controlled by Os ARF 12. These findings enrich our understanding of the biological functions of Os ARF 12, which also acts in regulating Pi homeostasis.