The Homeodomain-Leucine Zipper transcription factor AtHB16 plays a role in flower development

PEROTTI MF; MORENO JE; CHAN RL

Foc do Iguazu

Congreso; IPMB 2015; 2015

">Homeodomain-leucine zipper (HD-Zip) proteins are transcription factors (TFs) unique to plants.The HD-Zip family is composed of four subfamilies named I?IV; in Arabidopsis thaliana, subfamily Ihas 17 members encoding proteins of 35 kDa. Members that have been studied so far have beenrelated to developmental processes associated with abiotic stress. However, the function of mostHD-Zip I TFs is largely unknown. This study aims to understand the natural role of AtHB16, anuncharacterized member of the HD-Zip I subfamily.Different experimental strategies were applied In order to study the functional role of this TF.These strategies include the generation of AtHB16 silenced plants (amiR16) and the ectopicexpression of AtHB16 in Col-0 and rdr6 genetic backgrounds. AtHB16-silenced plants displayednormal morphological and developmental phenotypes during the vegetative phase. However,among these plants, four independent lines showed partial to total sterility. We observedmorphological alterations both in the female and male parts of their flowers. The femalereproductive organ showed asymmetric additional stigmas in the gynoecium whereas the malereproductive organ exhibited non-dehiscent anthers. However, these flowers were able tocomplete silique development after being artificially fertilized using pollen from wild type plants.These results suggest that AtHB16 would have a functional role in flower development. Furtherexperiments are being carried out to understand the molecular mechanisms displayed in AtHB16-silenced plants to generate the aberrant developmental phenotype.