AUTHOR=Hinrichs Martin , Fleck Alexander T. , Biedermann Eline , Ngo Ngoc S. , Schreiber Lukas , Schenk Manfred K. 

TITLE=An ABC Transporter Is Involved in the Silicon-Induced Formation of Casparian Bands in the Exodermis of Rice

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.00671

DOI=10.3389/fpls.2017.00671

ISSN=1664-462X

ABSTRACT=<p>Silicon (Si) promotes the formation of Casparian bands (CB) in rice and reduces radial oxygen loss (ROL). Further transcriptomic approaches revealed several candidate genes involved in the Si-induced formation of CB such as ATP binding cassette (ABC) transporter, Class III peroxidases, ligases and transferases. Investigation of these genes by means of overexpression (OE) and knockout (KO) mutants revealed the contribution of the ABC transporter (<italic>OsABCG25</italic>) to CB formation in the exodermis, which was also reflected in the expression of other <italic>OsABCG25</italic> in the Si-promoted formation of CB genes related to the phenylpropanoid pathway, such as phenylalanine-ammonia-lyase, diacylglycerol O-acyltransferase and 4-coumarate-CoA ligase. Differential CB development in mutants and Si supply also affected the barrier function of the exodermis. OE of the ABC transporter and Si supply reduced the ROL from roots and Fe uptake. No effect on ROL and Fe uptake could be observed for the KO mutant. The presented research confirms the impact of the <italic>OsABCG25</italic> in the Si-promoted formation of CB and its barrier functions.</p>