Analysis of TCP transcription factors and downstream regulatory networks in the basal land plant Marchantia polymorpha
Final Report Abstract
Functional analyses of the sole TCP-P gene MpTPC1 in the basal land plant Marchantia polymorpha revealed that knockout Mptcp1 mutant lines show a severely reduced vegetative thallus growth and extra tissue formation in female reproductive structures. MpTCP1 thus regulates Marchantia cell proliferation in a context-dependent manner. Mutant plants accumulate increased H2O2 levels and show an enhanced pigmentation in vegetative tissues. Biochemical analyses demonstrate that MpTCP1 controls the formation of novel red plant pigments, namely aminochrome and two derivatives, which likely exert protective functions against harmful irradiation such as UV-B light. MpTCP1 proteins interact redox dependently with DNA. This provides a mechanism to sense and respond to altered redox conditions by regulating the expression of a comprehensive downstream redox network comprising enzymes involved in H2O2 metabolism. Bryophytes lost the protective buffering capacities of an aqueous environment and experienced novel stresses. Given the detected growth regulatory and ROS sensing as well as ROS-regulatory capacities of MpTCP1, this key regulator likely contributed to adapt land plants to the novel challenges coinciding with a terrestrial life style and also to the diversification of land plant morphologies by affecting context-dependently cell proliferation processes.
Publications
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(2017) Insights into land plant evolution garnered from the Marchantia polymorpha genome. Cell 171, 287-304
Bowman J.L., Kohchi T., Yamato K.T., et al. (Marchantia genome consortium), Yotsui I., Zachgo S., Schmutz J.
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(2018) The Chara genome: secondary complexity and implications for plant terrestrialization. Cell 174, 448-464
Nishiyama T., Sakayama H., de Vries J., et al. (Chara genome consortium), Zachgo S., Langdale J., Maumus F., Van Der Straeten D., Gould S.B., Rensing S.A.
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(2019) MpTCP1 controls cell proliferation and redox processes in Marchantia polymorpha. New Phytologist, 224 (4), 1627-1641
Busch A., Deckena M., Almeida-Trapp M., Kopischke, S., Kock, C., Schuessler, E., Tsiantis, M., Mithofer, A., Zachgo S.
