An untranslated cis-element regulates the accumulation of multiple C₄ enzymes in Gynandropsis gynandra mesophyll cells
Williams, Ben P
Burgess, Steven J
The Plant Cell
American Society of Plant Biologists
MetadataShow full item record
Williams, B. P., Burgess, S. J., Reyna-Llorens, I., Knerova, J., Aubry, S., Stanley, S., & Hibberd, J. (2016). An untranslated cis-element regulates the accumulation of multiple C₄ enzymes in Gynandropsis gynandra mesophyll cells. The Plant Cell, 28 454-465. https://doi.org/10.1105/tpc.15.00570
C4 photosynthesis is a complex phenotype that allows more efficient carbon capture than the ancestral C3 pathway. In leaves of C4 species, hundreds of transcripts increase in abundance compared with C3 relatives and become restricted to mesophyll (M) or bundle sheath (BS) cells. However, no mechanism has been reported that regulates the compartmentation of multiple enzymes in M or BS cells. We examined mechanisms regulating CARBONIC ANHYDRASE 4 (CA4) in C4 Gynandropsis gynandra. Increased abundance is directed by both the promoter region and introns of the G. gynandra gene. A 9-nucleotide motif located in the 5’ untranslated region (UTR) is required for preferential accumulation of GUS in M cells. This element is present and functional in three additional 5’ UTRs and six 3’ UTRs where it determines accumulation of two isoforms of CA and pyruvate,orthophosphate dikinase in M cells. Although the GgCA4 5' UTR is sufficient to direct GUS accumulation in M cells, transcripts encoding GUS are abundant in both M and BS. Mutating the GgCA4 5' UTR abolishes enrichment of protein in M cells without affecting transcript abundance. The work identifies a mechanism that directs cell-preferential accumulation of multiple enzymes required for C4 photosynthesis.
We would like to thank the BBSRC for funding.
External DOI: https://doi.org/10.1105/tpc.15.00570
This record's URL: https://www.repository.cam.ac.uk/handle/1810/253284