Control of leaf blade outgrowth and floral organ development by LEUNIG , ANGUSTIFOLIA 3 and WOX transcriptional regulators

• Published in: The New phytologist 2019-09, Vol.223 (4), p.2024-2038
• Main Authors: Zhang, Fei, Wang, Hui, Kalve, Shweta, Wolabu, Tezera W., Nakashima, Jin, Golz, John F., Tadege, Million
• Format: Article
• Language: English
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.15921

Plant lateral organ development is a complex process involving both transcriptional activation and repression mechanisms. The WOX transcriptional repressor WOX 1/ STF , the LEUNIG ( LUG ) transcriptional corepressor and the ANGUSTIFOLIA 3 ( AN 3) transcriptional coactivator play important roles in leaf blade outgrowth and flower development, but how these factors coordinate their activities remains unclear. Here we report physical and genetic interactions among these key regulators of leaf and flower development. We developed a novel in planta transcriptional activation/repression assay and suggest that LUG could function as a transcriptional coactivator during leaf blade development. Mt LUG physically interacts with Mt AN 3, and this interaction appears to be required for leaf and flower development. A single amino acid substitution at position 61 in the SNH domain of Mt AN 3 protein abolishes its interaction with Mt LUG , and its transactivation activity and biological function. Mutations in lug and an3 enhanced each other's mutant phenotypes. Both the lug and the an3 mutations enhanced the wox1 prs leaf and flower phenotypes in Arabidopsis . Our findings together suggest that transcriptional repression and activation mediated by the WOX , LUG and AN 3 regulators function in concert to promote leaf and flower development, providing novel mechanistic insights into the complex regulation of plant lateral organ development.