Journal Article

AHL26, an AT-hook gene, negatively regulates hypocotyl growth and flowering time in Arabidopsis thaliana

Ahmed, Shahbaz, Hulbert, Anna K., Xin, Xin, Neff, Michael M.

2025

Overview

Background The AT-HOOK MOTIF CONTAINING NUCLEAR LOCALIZED (AHL) gene family in Arabidopsis contains 29 members, which evolved into two phylogenetic clades. Genes from this family play a role in several biological processes, but most of the members’ functions remain unknown. Results Here, we provide evidence that AHL26, a clade-a protein, negatively regulates hypocotyl growth and flowering time in Arabidopsis . Analysis of transgenic plants expressing an AHL26:AHL26:GUS translational fusion driven by 1.9 KB of the endogenous AHL26 promoter displayed GUS activity in the hypocotyl and apical meristem of light-grown seedlings. The overexpression of AHL26 resulted in the inhibition of hypocotyl growth and delayed flowering. However, the overexpression of a dominant-negative AHL26 with mutation in AT-hook motif, resulted in early flowering and longer hypocotyls than the WT and over-expression transgenic lines suggesting genetic redundancy between AHL26 and other AHL genes. Transcriptome analysis showed that the regulation of flowering time in AHL26 over-expression and dominant-negative mutants results from regulating flowering-related genes and pathways. Conclusion Our study highlights the significant role of AHL26 in hypocotyl growth and flowering time regulation. We further demonstrate that AHL26 regulates hypocotyl length in a light-dependent manner. Through transcriptomic analysis, we also show that the delayed flowering phenotype in our AHL26 over-expression plants is due to the negative regulation of flowering-promoting genes such as FT . Furthermore, transcriptome analysis provides insight into the biological processes and pathways through which AHL26 influences the control of flowering time.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Agriculture / AHL26 / Antibiotics / apical meristems / Arabidopsis / Arabidopsis - genetics / Arabidopsis - growth & development / Arabidopsis - metabolism / Arabidopsis - physiology / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Arabidopsis thaliana / AT-hook / Biological activity / Biomedical and Life Sciences / Botanical research / Cloning / Digitization / Dominant-negative mutation / family / Flowering / Flowers & plants / Flowers - genetics / Flowers - growth & development / Flowers - physiology / Gene expression / Gene Expression Regulation, Plant / Gene mutations / Gene regulation / Genes / Genes, Plant / Genetic aspects / genetically modified organisms / Genotype & phenotype / Hypocotyl - genetics / Hypocotyl - growth & development / Hypocotyls / Life Sciences / Light / Meristems / Mutation / Overexpression / phenotype / Phenotypes / phylogeny / Physiological aspects / Plant Sciences / Plants, Flowering of / Plants, Genetically Modified / Proteins / Redundancy / RNA-Seq / Seedlings / Seeds / Transcriptomes / Transcriptomics / Transgenic plants / Tree Biology