Identification of the 4CL family in cassava and expression pattern analysis of the Me4CL32 gene

Abstract The 4-coumarate coenzyme A ligase (4CL) plays a critical role in the phenylpropane metabolic pathway and is a key enzyme in plant growth metabolism and stress responses. In this study, 50 Me4CLs were identified within the cassava genome utilizing bioinformatics methods, and a comprehensive analysis of the cassava 4CL gene family was conducted. The results showed that the 50 4CL proteins were divided into four subfamilies, and members within the same subfamily share similar or identical gene structures. Co-linearity analysis revealed that cassava and rubber trees have the highest number of homologous genes, indicating a close homologous relationship between them. Analysis of 15 cis-acting elements in the promoter region of Me4CL32 reveals the presence of hormone-responsive elements such as gibberellin, auxin, abscisic acid, and as well as elements related to meristematic tissue regulation. The results of quantitative real-time PCR (qRT-PCR) showed alterations in Me4CL32 gene expression in response to abiotic stressors (drought, salt, cold, heat) as well as GA3 and ABA hormonal stimuli, implying the capacity of Me4CL32 to react to both environmental pressures and hormone stimuli. The RNA-seq transcriptome and single-cell transcriptome were opted to analyze the expression pattern of Me4CLs. Additionally, the subcellular localization of the Me4CL32 demonstrated the confinement of the Me4CL32 protein within cassava leaf chloroplasts. Delving into the functionality of this gene family aids in comprehending the growth, development, and stress resistance mechanisms within plants. Furthermore, it furnishes a theoretical underpinning for future investigations concerning resilient cassava germplasm and the enhancement of cassava's environmental tolerance.