Abstract
Plants can acclimate by using tropisms to link the direction of growth to environmental conditions. Hydrotropism allows roots to forage for water, a process known to depend on abscisic acid (ABA) but whose molecular and cellular basis remains unclear. Here we show that hydrotropism still occurs in roots after laser ablation removed the meristem and root cap. Additionally, targeted expression studies reveal that hydrotropism depends on the ABA signalling kinase SnRK2.2 and the hydrotropism-specific MIZ1, both acting specifically in elongation zone cortical cells. Conversely, hydrotropism, but not gravitropism, is inhibited by preventing differential cell-length increases in the cortex, but not in other cell types. We conclude that root tropic responses to gravity and water are driven by distinct tissue-based mechanisms. In addition, unlike its role in root gravitropism, the elongation zone performs a dual function during a hydrotropic response, both sensing a water potential gradient and subsequently undergoing differential growth.
DOI
10.1038/nplants.2017.57
Publication Date
2017-05-08
Publication Title
Nature Plants
Volume
3
Publisher
Nature Publishing Group
ISSN
2055-0278
Embargo Period
2024-11-22
Recommended Citation
Roberts, J. (2017) 'Root hydrotropism is controlled via a cortex-specific growth mechanism', Nature Plants, 3. Nature Publishing Group: Available at: https://doi.org/10.1038/nplants.2017.57
