The Homeodomain-Leucine Zipper transcription factor AtHB23 plays a role in root development

CHAN RL; PEROTTI MF; RIBONE PA

Buenos Aires

Simposio; Fronteras en Biociencias 2; 2016

The Homeodomain-Leucine Zipper transcription factor AtHB23 plays a role in root development

HD-Zip proteins aretranscription factors (TFs) unique to plants. In Arabidopsis thaliana, HD-ZipI subfamily has 17 members encoding proteins of 35 kDa, mainly associatedprimary with developmental processes related to abiotic stress. AtHB23, belongsto this subfamily and it was found to be expressed in different parts of theplants like shoot meristem region, leaf junction, and flowers. It is know that AtHB23could substitute its paralogue AtHB13 in pollen when the latter is defective.Aiming at unraveling thenatural role of AtHB23, different experimental strategies were applied,including histochemical analyses of transgenic plants containing a constructwith a GUS::GFP reporter under the control of the promoter region of AtHB23. GUSwas detected in different regions in the main root, principally in the zone ofthe new lateral roots. In the same way we observed expression of reporter GUSin the lateral roots. On the other hand, we generated AtHB23 silenced plants andectopic expression of AtHB23 in Col-0 genetic background. The morphologicalchanges detected in plants with altered levels of AtHB23 expression were related to roots development. AtHB23-silenced plants displayed shorterroots whereas 35S::AtHB23 plantspresented longer roots compared with control plants.These results suggest that AtHB23 would have a functional role inroot development.