Transcriptomics-based identification of transcription factors in the halophyte <i>Apocynum venetum</i> L.

The medicinal halophyte plant <i>Apocynum venetum</i> L. can tolerate high salt levels in the soil, which significantly affects its growth and development. To study the molecular mechanisms underlying its environmental adaptations, omics tools were employed. <i>Apocynum venetum</i> L. plants were subjected to varying levels of salt stress. The corresponding RNA of Apocyni Veneti Folium (AVF), the leaf of <i>Apocynum venetum</i> L., was sequenced using a <i>de novo</i> approach. Functional annotation and expression analysis were utilised to identify differentially expressed transcription factors (TFs). The classification of these TFs was further divided into different families, including AP2/ERF, bHLH, WRKY, and HSF. Under conditions of modest saline stress, the majority of TF genes exhibited a predilection for up-regulation, particularly <i>bHLHs</i>, which were discovered to be consistent with the build-up of flavonoid glycosides. In conjunction with previous proteomics and metabolomics findings, we have discovered that the gene bHLH35 is a potential candidate. This gene has shown changes at both the transcript and protein levels, indicating that it may play a crucial role in the biosynthesis of flavonoids under salt-induced environments. These findings provide invaluable information on the identification of key genes involved in elucidating flavonoid biosynthesis mechanisms and serve as a basis for the improvement of the halophyte AVF’s quality.