A novel durian (Durio zibethinus L.) homeodomain-leucine zipper (DzHD-ZIP) transcription factor 1.8 regulates the production of volatile sulfur compounds during fruit ripening

Abstract

Abstract Durian (Durio zibethinus L.), an important economic fruit crop in Southeast Asia, produces volatile sulfur compounds (VSCs) during fruit ripening. Methionine γ-lyase (MGL) is the key enzyme involved in the production of VSCs like methanethiol and ethanethiol, which coincide with an increased expression level of durian MGL (DzMGL) during fruit ripening. Although VSCs in durian pulps have been widely studied, the regulation of genes involved in VSC production in fruit has never been reported. Yeast one-hybrid (Y1H) screening of durian MGL promoter (pDzMGL) and ca. 1,200 Arabidopsis transcription factors (TFs) together with transcriptomic analysis revealed candidate HD-ZIP TF families in durian. Dual-luciferase assays, in silico promoter analysis, and electrophoresis mobility shift assays were performed to confirm the interaction between the promoter and DzHD-ZIP1.8. The ethylene-responsive DzHD-ZIP1.8 localizes in the nucleus. It acts as an activator and binds to the promoter of DzMGL to control its expression during ripening. Here, a TF that regulates the expression of DzMGL in durian fruit during ripening was first identified. This study elucidates the molecular regulation of an important gene involved in VSC production, which influences consumer preferences.