Epidermal expression of a sterol biosynthesis gene regulates root growth by a non-cell autonomous mechanism in Arabidopsis

Short, E.; Pullen, M.; Imriz, G.; Liu, D.; Cope-Selby, N.; Hetherington, F.; Smertenko, A.; Hussey, P.J.; Topping, J.F.; Lindsey, K.

Abstract

The epidermis is hypothesized to play a signalling role during plant development. One class of mutants showing defects in signal transduction and radial patterning are those in sterol biosynthesis. The expectation is that living cells require sterols, but it is not clear that all cell types express sterol biosynthesis genes. The HYDRA1 (HYD1) gene of Arabidopsis encodes sterol Δ8-Δ7 isomerase, and although hyd1 seedlings are defective in radial patterning across several tissues, we show that the HYD1 gene is expressed most strongly in the root epidermis. Transgenic activation of HYD1 transcription in the epidermis of hyd1 null mutants reveals a major role in root patterning and growth. HYD1 expression in the vascular tissues and root meristem, though not endodermis or pericycle, also leads to some phenotypic rescue. Phenotypic rescue is associated with rescued patterning of the PIN1 and PIN2 auxin efflux carriers. The importance of the epidermis in controlling root growth and development is proposed to be in part due to its role as a site for sterol biosynthesis, and auxin is a candidate for the non-cell autonomous signal.

Citation

Short, E., Pullen, M., Imriz, G., Liu, D., Cope-Selby, N., Hetherington, F., …Lindsey, K. (2018). Epidermal expression of a sterol biosynthesis gene regulates root growth by a non-cell autonomous mechanism in Arabidopsis. Development, 145(10), Article dev160572. https://doi.org/10.1242/dev.160572

• Journal Article Type: Article
• Acceptance Date: Apr 16, 2018
• Online Publication Date: Apr 25, 2018
• Publication Date: May 15, 2018
• Deposit Date: Oct 26, 2017
• Publicly Available Date: Apr 27, 2018
• Journal: Development.
• Print ISSN: 0950-1991
• Electronic ISSN: 1477-9129
• Publisher: The Company of Biologists
• Peer Reviewed: Peer Reviewed
• Volume: 145
• Issue: 10
• Article Number: dev160572
• DOI: https://doi.org/10.1242/dev.160572
• Public URL: https://durham-repository.worktribe.com/output/1372952