Tissue‐specific inactivation by cytosine deaminase/uracil phosphoribosyl transferase as a tool to study plant biology. (19th November 2019)

• Record Type: Journal Article
• Authors: Leonhardt, Nathalie; Divol, Fanchon; Chiarenza, Serge; Deschamps, Sabrina; Renaud, Jeanne; Giacalone, Cécile; Nussaume, Laurent; Berthomé, Richard; Péret, Benjamin
• Is Part Of: Plant journal. Volume 101:Number 3(2020)
• Page Start: 731
• Page End: 741
• Publication Date: 2019-11-19
• Subjects: Arabidopsis thaliana -- tissue‐specific inactivation -- root growth -- lateral root development -- stomatal regulation -- technical advance; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.14569
• Languages: English
• ISSNs: 0960-7412

Abstract

Summary: Recent advances in the study of plant developmental and physiological responses have benefited from tissue‐specific approaches, revealing the role of some cell types in these processes. Such approaches have relied on the inactivation of target cells using either toxic compounds or deleterious genes; however, both tissue‐specific and truly inducible tools are lacking in order to precisely target a developmental window or specific growth response. We engineered the yeast fluorocytosine deaminase (FCY1) gene by creating a fusion with the bacterial uracil phosphoribosyl transferase (UPP) gene. The recombinant protein converts the precursor 5‐fluorocytosine (5‐FC) into 5‐fluorouracyl, a drug used in the treatment of a range of cancers, which triggers DNA and RNA damage. We expressed the FCY‐UPP gene construct in specific cell types using enhancer trap lines and promoters, demonstrating that this marker acts in a cell‐autonomous manner. We also showed that it can inactivate slow developmental processes like lateral root formation by targeting pericycle cells. It also revealed a role for the lateral root cap and the epidermis in controlling root growth, a faster response. The 5‐FC precursor acts systemically, as demonstrated by its ability to inhibit stomatal movements when supplied to the roots in combination with a guard cell‐specific promoter. Finally, we demonstrate that the tissular inactivation is reversible, and can therefore be used to synchronize plant responses or to determine cell type‐specific functions during different developmental stages. This tool will greatly enhance our capacity to understand the respective role of each cell type in plant physiology and development. Significance Statement: Combining the tissue‐specific expression of cytosine deaminase and uracil phosphoribosyl transferase and the application of their precursor 5‐fluorocytosine allows the specific inactivation of targeted tissues. This tool reveals a role for the lateral root cap and the epidermis in controlling primary root growth and demonstrates that this mechanism acts in a tissue‐specific and reversible manner, therefore opening the way to a better understanding of the physiological and developmental processes at tissular and cellular levels.