ARGONAUTE2 enhances grain length and salt tolerance by activating BIG GRAIN3 to modulate cytokinin distribution in rice (Plant Cell)

Is it possible to simultaneously increase two incompatible features like grain yield and stress tolerance? Yin et al. suggest that optimizing cytokinin distribution in plant tissues is a promising strategy for that. ARGONAUTE2 (AGO2) and BIG GRAIN3 (BG3) genes work together promoting at the same time grain size and salt tolerance in rice. While AGO2 protein regulates chromatin condensation activating BG3 expression in AGO2-overexpressing (A2OX) plants, BG3 modulates cytokinin distribution, thereby increasing grain size and salt tolerance. The authors observed an increase in cytokinin levels in roots but a decrease in shoots, where BG3 was activated. Moreover, the same cytokinin distribution pattern was found in salt-treated plants, indicating that plants adjust this pattern to adapt to salt stress. These findings can help maintaining stable and high rice yields under saline soils. (Summary by Elisandra Pradella @Elisandra_MP) Plant Cell 10.1105/tpc.19.00542