Roles of a cryptochrome in carbon fixation and sucrose metabolism in the liverwort Marchantia polymorpha

Abstract

In vascular plants, blue-light photoreceptors and cryptochromes contain a myriad of roles and functions to adapt to different ambient light conditions, while the roles of cryptochromes in bryophytes have been rarely reported. In this study, we investigated functions of a single-copy ortholog of cryptochrome (MpCRY) in the liverwort Marchantia polymorpha. Knock-out of MpCRY showed that a large number of the mutant plants exhibited asymmetric growth of thalli under blue light. Transcriptome analyses indicated that MpCRY is mainly involved in photosynthesis and sugar metabolism. Further physiological analysis showed that Mpcry mutant exhibited a reduction in CO2 uptake and sucrose metabolism. In addition, exogenous application of sucrose or glucose partially restored the symmetrical growth of the Mpcry mutant thalli. Together, these results suggest that MpCRY is involved in the symmetrical growth of thallus and the regulation of carbon fixation and sucrose metabolism in M. polymorpha.