The effect of environmental stresses on growth regulation
Background: Plant growth can be significantly affected by stress protective signalling (e.g. immunity) and, as reported for growth-immunity trade-offs, impair crop productivity in the field; e.g. reduce barley yield by 10%. The co-activation of growth and stress protection exists in natural plant populations and might have been lost in (some) crops; e.g. as a result of breeding-based selection. In addition, we found that growth-immunity trade-offs was abolished in plants colonised by the mutualistic fungus S. indica. By focusing on growth-immunity trade-offs, we observed that immunity does not affect root system architecture but apparently inhibits root meristem functionality. Understanding the molecular nature of the antagonism would allow to generate crops with high yield and high stress resilience.
Project: We observed that immunity (e.g. elicited by flg22) inhibits cell cycle signalling and cell division at the root meristem (without affecting stem cell niche function), which impedes growth. In a genetic screen we identified that specific overexpression of the cell cycle regulator CDKB1;1 resulted in plants with undisturbed growth while immunity activation and pathogen resistance was unimpaired. We are interested in understanding why and how immunity inhibits the cell cycle/growth. Considering the conservation of cell cycle regulation, our findings are very likely to be translatable to other systems.
Lab tools / techniques: Cell cycle/growth and immunity assays, CLSM, biochemical assays (e.g. co-IPs)
Rich, C., Reitz, M.U., Eichmann, R., Hermann, S., Woolley-Allen, K., Esteban, E., Pasha, A., Kogel, K.H., Provart, N.J., Ott, S.1, Schäfer, P.1,2 Cell type identity determines transcriptomic immurrrne responses in Arabidopsis thaliana roots. bioRxiv doi.org/10.1101/302448.
Eichmann, R., Schäfer, P. (2015) Growth versus immunity-a redirection of the cell cycle? Current Opinion in Plant Biology 26:106-112.
Reitz, M.U., Gifford, M.L., Schäfer, P. (2015) Hormone activities and the cell cycle machinery in immunity-triggered growth inhibition. Journal of Experimental Botany 66:2187-97.