Tropism articles from across Nature Portfolio

Plants often need to bend their organs during their growth and development. It is a complex process, and the different mechanisms involved are discussed in the light of recent findings about genes, signalling, modelling and biomechanics.

Directionality of auxin transport is determined by polar localization of PIN-FORMED (PIN) proteins. Here the authors show that Arabidopsis WAV3 E3 ubiquitin ligases contribute to PIN polarity by selectively antagonizing ectopic deposition of de novo synthesized PIN proteins following cell division.

Parasitic plants are able to grow towards potential hosts. Here the authors show that strigolactones produced by the host plants can act as chemoattractants for the root parasites Phtheirospermum japonicum and Striga hermonthica.

The plasma membrane-localized NPH3 protein is required for phototropic growth in Arabidopsis. Here the authors show that phototropin 1 phosphorylates NPH3 at a conserved C-terminal sequence motif triggering binding of 14-3-3 proteins to NPH3 that is necessary for the phototropic response.

Gravitropism is the process by which plants perceive and respond to gravity. Here the authors identify a minus-end-directed kinesin required for gravity-triggered actin filament rearrangement and negative gravitropic response in the moss Physcomitrella patens, thus linking a microtubule-based cellular motor to gravitropism via actin.