Growth plasticity from a steroid hormone signaling perspective

How do cells of different identities behave in synchrony to maintain a coherent organ growth? This question is tackled in our lab by 1) decoding the role of the steroid hormones brassinosteroid (BR) signaling pathway in the cell and tissue types composing the Arabidopsis root and by 2) investigating how these signals are tuned by the environment. It is demonstrated that the spatial distribution of BR activity is an important fine-tuning determinant of root growth; in specific cell types, BR signaling drives cell elongation and cell proliferation, while in others, it restrains them. I will highlight recent studies showing that activation of BR components in the root, and the resulting extent of root growth also depend on nutrient availability. Altered BR signaling intensity modulates nutrient accumulation, imparting a feedback effect. This mechanism is expected to facilitate plant adaptation to distinct microenvironments in the soil.