Distinct C4 sub-types and C3 bundle sheath isolation in the Paniceae grasses

Authors: Washburn, Jacob; STRABLE, JOSH - North Carolina State University; DICKINSON, PATRICK - University Of Cambridge; KOTHAPALLI, SATYA - University Of Missouri; BROSE, JULIA - University Of Missouri; COVSHOFF, SARAH - University Of Cambridge; CONANT, GAVIN - North Carolina State University; HIBBERD, JULIAN - University Of Cambridge; PIRES, CHRIS - University Of Missouri

Submitted to: Plant Direct
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/8/2021
Publication Date: 12/27/2021
Citation: Washburn, J.D., Strable, J., Dickinson, P., Kothapalli, S.S., Brose, J.M., Covshoff, S., Conant, G.C., Hibberd, J.M., Pires, C.J. 2021. Distinct C4 sub-types and C3 bundle sheath isolation in the Paniceae grasses. Plant Direct. 5(12): Article e373. https://doi.org/10.1002/pld3.373.
DOI: https://doi.org/10.1002/pld3.373

Interpretive Summary: C4 photosynthesis is one of the most efficient ways in which plants turn sunlight into chemical energy, and it is used by many of the world’s most productive crops. Relatively little is understood about natural genetic variability within C4 photosyntheses and how it might impact plant growth. Detailed anatomical, genetic, and biochemical data was collected and analyzed from closely related but photosynthetically diverse plants. These analyses indicate that C4 photosynthesis can be performed very differently from one species to the next. Better understanding these differences could lead to new ways of improving crop plants.

Technical Abstract: In C4 plants, the enzymatic machinery underpinning photosynthesis can vary, with, for example, three distinct C4 acid decarboxylases being used to release CO2 in the vicinity of RuBisCO. For decades, these decarboxylases have been used to classify C4 species into three biochemical sub-types. However, more recently the notion that C4 species mix and match C4 acid decarboxylases has increased in popularity and, as a consequence, the validity of specific biochemical sub-types has been questioned. Using five species from the grass tribe Paniceae, we show that, although in some species transcripts encoding multiple C4 acid decarboxylases accumulate, in others, transcript abundance and enzyme activity is almost entirely from one decarboxylase. n addition, the development of a bundle sheath isolation procedure for a close C3 species in the Paniceae enables the preliminary exploration of C4 sub-type evolution.