Auxin/cytokinin antagonism in shoot development: from moss to seed plants

Abstract

Cammarata et al. (2023) show that in the model non-vascular plant Physcomitrium patens the growth hormone indole acetic acid (IAA) can inhibit growth and development of leaves (phyllids) from shoots, while cytokinin (CK) eliminates this effect. Most significantly, the effect on growth of the observed antagonism between IAA and CK has also been reported for vascular plants in the literature. These new data from moss emphasize the evolutionary preservation of this interaction between these hormones in the control of shoot growth.