Genome-wide identification of bZIP family genes and screening of candidate AarbZIPs involved in terpenoid biosynthesis in Artemisia argyi / 中国中药杂志

Artemisia argyi is an important medicinal and economic plant in China, with the effects of warming channels, dispersing cold, and relieving pain, inflammation, and allergy. The essential oil of this plant is rich in volatile terpenoids and widely used in moxi-bustion and healthcare products, with huge market potential. The bZIP transcription factors compose a large family in plants and are involved in the regulation of plant growth and development, stress response, and biosynthesis of secondary metabolites such as terpenoids. However, little is known about the bZIPs and their roles in A. argyi. In this study, the bZIP transcription factors in the genome of A. argyi were systematically identified, and their physicochemical properties, phylogenetic relationship, conserved motifs, and promoter-binding elements were analyzed. Candidate AarbZIP genes involved in terpenoid biosynthesis were screened out. The results showed that a total of 156 AarbZIP transcription factors were identified at the genomic level, with the lengths of 99-618 aa, the molecular weights of 11.7-67.8 kDa, and the theoretical isoelectric points of 4.56-10.16. According to the classification of bZIPs in Arabidopsis thaliana, the 156 AarbZIPs were classified into 12 subfamilies, and the members in the same subfamily had similar conserved motifs. The cis-acting elements of promoters showed that AarbZIP genes were possibly involved in light and hormonal pathways. Five AarbZIP genes that may be involved in the regulation of terpenoid biosynthesis were screened out by homologous alignment and phylogenetic analysis. The qRT-PCR results showed that the expression levels of the five AarbZIP genes varied significantly in different tissues of A. argyi. Specifically, AarbZIP29 and AarbZIP55 were highly expressed in the leaves and AarbZIP81, AarbZIP130, and AarbZIP150 in the flower buds. This study lays a foundation for the functional study of bZIP genes and their regulatory roles in the terpenoid biosynthesis in A. argyi.

Characterization of bZIP transcription factors from Dimocarpus longanDimocarpus longan Lour. and analysis of their tissue-specific expression patterns and response to heat stress

Members of the bZIP transcription factor family play crucial roles in the regulation of plant development, biosynthesis of secondary metabolites, and response to abiotic and biotic stresses. To date, multiple bZIPs have been identified and investigated in numerous plant species. However, few studies have characterized bZIPs from Dimocarpus longan Lour. In this study, nine bZIPs from D. longan were identified from RNA-Seq data and further verified using the NCBI conserved domain search tool and Pfam database. Bioinformatics tools were used to systematically analyse the physicochemical properties, protein structures, multiple sequence alignment, motif compositions, evolutionary relationships, secondary structures, subcellular localization, phosphorylation sites, signal peptides, GO annotations and protein–protein interactions of the DlbZIPs. The expression patterns of the nine DlbZIPs were evaluated by qRT-PCR in roots and leaves and in response to varying durations of a 38C heat treatment. DlbZIP3, DlbZIP5, DlbZIP6 and DlbZIP7 were differentially expressed between root and leaf tissues. All nine DlbZIPs responded to heat treatment in both roots and leaves, but their specific expression levels differed. DlbZIP4 and DlbZIP8 were highly expressed in roots after heat treatment, whereas DlbZIP1 and DlbZIP5 were highly expressed in leaves after heat treatment. These findings lay a foundation for increasing active secondary metabolite content and improving abiotic stress tolerance in D. longan using transgenic technology