Understanding Transcription Factors and How They Affect Processes in Cucumber Sex Determination

Abstract

Plant reproduction is a fundamental process on Earth from the perspective of biodiversity, biomass gain, and crop productivity. It is therefore important to understand the sex determination process, and many researchers are investigating the molecular basis of this phenomenon. However, information on the influence of transcription factors (TFs), genes that encode DNA-binding proteins, on this process is limited, although cucumber is a model plant in this regard. In the present study, based on RNA-seq data for differentially expressed genes (DEGs), we aimed to investigate the regulatory TFs that may influence the metabolic processes in the shoot apex containing the forming flower buds. Therefore, the annotation of the genome of the B10 cucumber line was supplemented with the assigned families of transcription factors. By performing ontology analyses of the DEGs, the processes they participate in were identified, and TFs were located among the results. In addition, TFs that have significantly overrepresented targets among DEGs were detected, and sex-specific interactome network maps were generated, indicating the regulatory TFs based on their effects on DEGs and furthermore, on the processes leading to the formation of different-sex flowers. Among the most overrepresented TF families in the sex comparisons were the NAC, bHLH, MYB, and bZIP families. An interaction network analysis indicated the most abundant families among DEGs’ regulatory TFs were MYB, AP2/ERF, NAC, and bZIP, and those with the most significant impact on developmental processes were identified, namely the AP/ERF family, followed by DOF, MYB, MADS, and others. Thus, the networks’ central nodes and key regulators were identified with respect to male, female, and hermaphrodite forms. Here, we proposed the first model of the regulatory network of TFs that influences the metabolism of sex development in cucumber. These findings may help us to understand the molecular genetics and functional mechanisms underlying sex determination processes.

Impact of Climate Change on Regulation of Genes Involved in Sex Determination and Fruit Production in Cucumber

“…They can upregulate or downregulate gene expression, and possess various motifs, including DNA-binding and activation motifs. There are several families of transcription factors with different motifs in their protein structure, such as bZIP, HD-ZIP III, NAC, AP2/EREBP, WRKY, bHLH, TCP, MADS Box, ARF and MYB families [ 109 ]. For example, the HD-ZIP IV family transcription factor GL2-LIKE interacts with CsJAZ1 to form a complex that regulates male flower development, seed viability and pollen intensity by regulating the expression of the FT gene expression [ 110 ].…”