PT  - JOURNAL ARTICLE
AU  - Patrick J. Dickinson
AU  - Jana Kneřová
AU  - Marek Szecówka
AU  - Sean S. Stevenson
AU  - Steven J. Burgess
AU  - Hugh Mulvey
AU  - Anne-Maarit Bågman
AU  - Allison Gaudinier
AU  - Siobhan M. Brady
AU  - Julian M. Hibberd
TI  - A bipartite transcription factor module controlling expression in the bundle sheath of <em>Arabidopsis thaliana</em>
AID  - 10.1101/380188
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 380188
4099  - http://biorxiv.org/content/early/2020/07/06/380188.short
4100  - http://biorxiv.org/content/early/2020/07/06/380188.full
AB  - C4 photosynthesis evolved repeatedly from the ancestral C3 state, improving photosynthetic efficiency by ∼50%. In most C4 lineages photosynthesis is compartmented between mesophyll and bundle sheath cells but how gene expression is restricted to these cell types is poorly understood. Using the C3 model Arabidopsis thaliana we identified cis-elements and transcription factors driving expression in bundle sheath strands. Upstream of the bundle sheath preferentially expressed MYB76 gene we identified a region necessary and sufficient for expression containing two cis-elements associated with the MYC and MYB families of transcription factors. MYB76 expression is reduced in mutant alleles for each. Moreover, down-regulated genes shared by both mutants are preferentially expressed in the bundle sheath. Our findings are broadly relevant for understanding the spatial patterning of gene expression, provide specific insights into mechanisms associated with evolution of C4 photosynthesis and identify a short tuneable sequence for manipulating gene expression in the bundle sheath.Competing Interest StatementThe authors have declared no competing interest.