A bipartite transcription factor module controlling expression in the bundle sheath of Arabidopsis thaliana

• Published in: Nature plants Vol. 6; no. 12; pp. 1468 - 1479
• Main Authors: Dickinson, Patrick J., Kneřová, Jana, Szecówka, Marek, Stevenson, Sean R., Burgess, Steven J., Mulvey, Hugh, Bågman, Anne-Maarit, Gaudinier, Allison, Brady, Siobhan M., Hibberd, Julian M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-12-2020; Nature Publishing Group
• Subjects: 631/449; 631/449/1659; 631/449/1734; 631/449/2669; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis thaliana; Biomedical and Life Sciences; Evolution; Gene expression; Gene Expression Regulation, Plant; Genes, Plant; Life Sciences; Mesophyll; Mutants; Myc protein; Photosynthesis; Photosynthesis - genetics; Plant Leaves - genetics; Plant Leaves - metabolism; Plant Sciences; Sheaths; Strands; Transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 2055-0278; 2055-0278
• DOI: 10.1038/s41477-020-00805-w

C
4
photosynthesis evolved repeatedly from the ancestral C
3
state, improving photosynthetic efficiency by ~50%. In most C
4
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 C
3
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 these transcription factors. Moreover, downregulated 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 the evolution of C
4
photosynthesis and identify a short tuneable sequence for manipulating gene expression in the bundle sheath.
In most C
4
lineages, photosynthesis is compartmented between mesophyll and bundle sheath cells. Using the C
3
model
Arabidopsis
, this study identifies
cis
-elements and transcription factors driving gene expression restricted to bundle sheath strands.