S1 basic leucine zipper transcription factors shape plant architecture by controlling C/N partitioning to apical and lateral organs

Kreisz, P.; Hellens, A. M.; Froeschel, C.; Krischke, M.; Maag, D.; Feil, R.; Wildenhain, T.; Draken, J.; Braune, G.; Erdelitsch, L.; Cecchino, L.; Wagner, T. C.; Mueller, M. J.; Becker, D.; Lunn, J. E.; Hanson, J.; Beveridge, C. A.; Fichtner, F.; Barbier, F. F.; Weiste, C.

doi:10.1101/2023.05.23.541964

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bioRxiv · 10.1101/2023.05.23.541964

S1 basic leucine zipper transcription factors shape plant architecture by controlling C/N partitioning to apical and lateral organs

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Abstract

Plants exhibit an immense plasticity in their architecture. While the impact of hormonal regulation is well-characterised, the importance of sugar-signalling has just recently emerged. Here, we addressed which sugar-signalling components mediate the trade-off between growth of apical versus lateral meristems and how they control organ sink-strength. Thereby, we unravelled a novel developmental function of the sugar-controlled S1 basic-leucine-zipper (S1-bZIP) transcription factors in establishing global source-sink interactions. Applying comprehensive molecular, analytical, and genetic approaches, we demonstrate that S1-bZIPs operate in a redundant manner to control tissue-specific expression of defined SWEET sugar-transporters and the GAT1_2.1 glutaminase. By these means, S1-bZIPs control carbohydrate (C)-channelling from source leaves to apical shoot and root organs and tune systemic organic nitrogen (N)-supply to restrict lateral organ formation by C/N depletion. Knowledge of the underlying mechanisms controlling plant C/N partitioning is of pivotal importance for breeding strategies to generate plants with desired architectural and nutritional characteristics.

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Kreisz, P., Hellens, A. M., Froeschel, C., Krischke, M., Maag, D., Feil, R., Wildenhain, T., Draken, J., Braune, G., Erdelitsch, L., Cecchino, L., Wagner, T. C., Mueller, M. J., Becker, D., Lunn, J. E., Hanson, J., Beveridge, C. A., Fichtner, F., Barbier, F. F., Weiste, C.. 2023-05-24. S1 basic leucine zipper transcription factors shape plant architecture by controlling C/N partitioning to apical and lateral organs. https://doi.org/10.1101/2023.05.23.541964

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