Arabidopsis inositol polyphosphate 6-/3-kinase (AtIpk2beta) is involved in axillary shoot branching via auxin signaling.
The Arabidopsis (Arabidopsis thaliana) inositol polyphosphate 6-/3-kinase gene (AtIpk2beta) is known to participate in inositol phosphate metabolism. However, little is known about its physiological functions in higher plants. Here, we report that AtIpk2beta regulates Arabidopsis axillary shoot branching. By overexpressing AtIpk2beta in the wild type and mutants, we found that overexpression of AtIpk2beta leads to more axillary shoot branches. Further analysis of AtIpk2beta overexpression lines showed that axillary meristem forms earlier and the bud outgrowth rate is also accelerated, resulting in more axillary shoot branches. The AtIpk2beta promoter/beta-glucuronidase (GUS) fusion (AtIpk2betaGUS) expression pattern is similar to that of the auxin reporter DR5GUS. Moreover, AtIpk2beta can be induced in response to exogenous indole-3-acetic acid (IAA) treatments. In addition, AtIpk2beta overexpression plants exhibit IAA-related phenotypes and are more resistant to exogenous IAA treatments. Further analysis employing reverse transcription-polymerase chain reaction shows that some genes, including auxin-biosynthesis (CYP83B1), auxin-transport (PIN4), and auxin-mediated branching genes (MAX4 and SPS), are regulated by AtIpk2beta. Taken together, our data provide insights into a role for AtIpk2beta in axillary shoot branching through the auxin signaling pathway.
Zhang
Zai-Bao
ZB
Key Laboratory of MOE for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China.
Yang
Guang
G
Arana
Fernando
F
Chen
Zhen
Z
Li
Yan
Y
Xia
Hui-Jun
HJ
D017360:Arabidopsis / Q000201:enzymology* / Q000254:growth & development / Q000502:physiology; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017930:Genes, Reporter; D007210:Indoleacetic Acids / Q000378:metabolism*; D018519:Meristem / Q000254:growth & development; D008969:Molecular Sequence Data; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D018520:Plant Shoots / Q000254:growth & development*; D015398:Signal Transduction / Q000502:physiology
D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; C523083:IPK2beta protein, Arabidopsis; D017853:Phosphotransferases (Alcohol Group Acceptor)