Identification of MEDIATOR16 as the Arabidopsis COBRA suppressor, MONGOOSE1

Sorek, N.; Szemenyei, H.; Sorek, H.; Landers, A.; Knight, H.; Bauer, S.; Wemmer, D.E.; Somerville, D.R.

Abstract

We performed a screen for genetic suppressors of cobra, an Arabidopsis mutant with defects in cellulose formation and an increased ratio of unesterified/esterified pectin. We identified a suppressor named mongoose1 (mon1) that suppressed the growth defects of cobra, partially restored cellulose levels, and restored the esterification ratio of pectin to wild-type levels. mon1 was mapped to the MEDIATOR16 (MED16) locus, a tail mediator subunit, also known as SENSITIVE TO FREEZING6 (SFR6). When separated from the cobra mutation, mutations in MED16 caused resistance to cellulose biosynthesis inhibitors, consistent with their ability to suppress the cobra cellulose deficiency. Transcriptome analysis revealed that a number of cell wall genes are misregulated in med16 mutants. Two of these genes encode pectin methylesterase inhibitors, which, when ectopically expressed, partially suppressed the cobra phenotype. This suggests that cellulose biosynthesis can be affected by the esterification levels of pectin, possibly through modifying cell wall integrity or the interaction of pectin and cellulose.

Citation

Sorek, N., Szemenyei, H., Sorek, H., Landers, A., Knight, H., Bauer, S., …Somerville, D. (2015). Identification of MEDIATOR16 as the Arabidopsis COBRA suppressor, MONGOOSE1. Proceedings of the National Academy of Sciences, 112(52), 16048-16053. https://doi.org/10.1073/pnas.1521675112

• Journal Article Type: Article
• Acceptance Date: Dec 11, 2015
• Online Publication Date: Dec 11, 2015
• Publication Date: Dec 29, 2015
• Deposit Date: Jan 5, 2016
• Publicly Available Date: Aug 9, 2016
• Journal: Proceedings of the National Academy of Sciences
• Print ISSN: 0027-8424
• Electronic ISSN: 1091-6490
• Publisher: National Academy of Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 112
• Issue: 52
• Pages: 16048-16053
• DOI: https://doi.org/10.1073/pnas.1521675112
• Public URL: https://durham-repository.worktribe.com/output/1395411