Novel mechanisms of strigolactone-induced DWARF14 degradation in Arabidopsis thaliana.

In angiosperms, the strigolactone receptor is the α/β hydrolase DWARF14 (D14) that, upon strigolactone binding, undergoes conformational changes, triggers strigolactone-dependent responses, and hydrolyses strigolactones. Strigolactone signalling involves the formation of a complex between strigolactone-bound D14, the E3-ubiquitin ligase SCFMAX2, and the transcriptional corepressors SMXL6/7/8, which become ubiquitinated and degraded by the proteasome. Strigolactone also destabilizes the D14 receptor.

The strigolactone receptor D14 targets SMAX1 for degradation in response to GR24 treatment and osmotic stress.

The effects of the phytohormone strigolactone (SL) and smoke-derived karrikins (KARs) on plants are generally distinct, despite the fact that they are perceived through very similar mechanisms. The homologous receptors DWARF14 (D14) and KARRIKIN-INSENSITIVE2 (KAI2), together with the F-box protein MORE AXILLARY GROWTH2 (MAX2), mediate SL and KAR responses, respectively, by targeting different SMAX1-LIKE (SMXL) family proteins for degradation. These mechanisms are putatively well-insulated, with D14-MAX2 targeting SMXL6, SMXL7, and SMXL8 and KAI2-MAX2 targeting SMAX1 and SMXL2 in .

Exploring the protein-protein interaction landscape in plants.

Protein-protein interactions (PPIs) represent an essential aspect of plant systems biology. Identification of key protein players and their interaction networks provide crucial insights into the regulation of plant developmental processes and into interactions of plants with their environment. Despite the great advance in the methods for the discovery and validation of PPIs, still several challenges remain.

To grow or not to grow, a power-saving program induced in dormant buds.

Plant shoot branching patterns determine leaf, flower and fruit production, and thus reproductive success and yield. Branch primordia, or axillary buds, arise in the axils of leaves and their decision to either grow or enter dormancy is coordinated at the whole plant level. Comparisons of transcriptional profiles of axillary buds entering dormancy have identified a shared set of responses that closely resemble a Low Energy Syndrome.