The Zinc Finger proteinSlZFP2 is essential for tomato fruit locular tissue morphogenesis

Abstract

ABSTRACTIn tomato (Solanum lycopersicum L.) fruit, the locular tissue (LT) is a unique jelly-like tissue that differentiates from the central axis of the fruit after ovule fertilization. LT is essential for seed development and dispersal by preventing early germination and initiating fruit ripening. In this work, we studied a “gel-less” mutant and identified the underlying mutation in the coding sequence of the C2H2 zinc finger transcription factor (TF)SlZFP2. Histological, cytological and molecular characterization from knockout-CRISPR/Cas9 lines for this gene revealed the strong and early impact ofzfp2mutation on cell cycle and endocycle in LT. Additionally, model-based analysis of cellular data revealed that cell cycle was the main altered process, explaining thezfp2mutant phenotype. Further laser capture microdissection coupled with RNA-Seq analysis of young LT highlighted global expression changes between WT andzfp2mutant and led to a preliminary list of potential direct targets of theSlZFP2 TF. This multifaceted approach not only uncovered a new role forSlZFP2 TF as an essential regulator of LT morphogenesis, but also provides a foundation for future works aimed at deciphering the intricate regulatory networks governing fruit tissue development in tomato.One sentence summaryAlteration of cell division and endoreduplication in agel-lessmutant reveals the role of the transcription factorSlZFP2 in tomato locular tissue morphogenesis