Analysis of heat shock transcription factor gene family in cocoa

ABSTRACT The heat shock factor (HSF) is crucial for plant stress regulation. This study aimed to analyze the role and characteristics of the HSF protein in Theobroma cacao L. The assesment was carried out bioinformatically, consisting of HSF identification in the cocoa genome, analysis of physical properties, gene structure, motifs, and subcellular, phylogenetics and chromosomal localization. A total of 26 HSF proteins were identified, presenting a complete structure consisting of exons and introns. The analysis of the TcHSF gene promoter revealed several cis-acting elements that act on stress, such as the responsive elements to anaerobiosis, abscisic acid, and low temperature, as well as the myeloblastosis binding sequence. Almost all TcHSF exhibited a strong degree of subcellular localization in the nucleus. Cocoa phylogenetics showed that Thecc1EG037635t1 is in a clade with At5G54070, with a bootstrap value of 90 %. The three best candidates (TcHSF-14, TcHSF-24, and TcHSF-25) are recommended for further functional analysis, due to their potential for increasing cocoa value.