Abstract:

The basic/helix-loop-helix (bHLH) transcription factor represents the second largest family of transcription factors in the plant kingdom. It is widely distributed across the genomes of various plants and plays crucial regulatory roles in plant growth, development, secondary metabolism, and responses to abiotic stresses. Here, we present a comprehensive review focusing on the structural characteristics, taxonomic rules, and biological functions of the bHLH gene family, with particular emphasis on its involvement in plant growth, development, responses to abiotic stresses (such as drought, low temperature, salt, and heavy metals), and its significant role in the biosynthesis and dynamic accumulation of secondary metabolites. This thorough investigation allows for a deeper understanding of the contributions of bHLH to growth, development, stress resistance, and quality formation in plants. Moreover, it provides valuable insights for future research concerning the molecular regulatory mechanisms of bHLH in plant growth, development, stress resistance, quality formation, and the exploration of germplasm resources. Furthermore, bHLH has emerged as a prominent focus in the realms of molecular biopharmacology and ecological agriculture of Chinese medicine due to its extensive involvement in regulating the synthesis and accumulation of secondary metabolites in plants. We also summarize recent progress on the bHLH gene family and its members within two medicinal plants, namely Salvia Miltiorrhiza and Artemisia annua. This investigation aims to offer valuable references for in-depth studies on the bHLH gene family in medicinal plants and to propose novel ideas for the advancement of molecular breeding and anthropomorphic cultivation of medicinal plants, as well as the development of ecological agriculture for Chinese medicine.

Key words: medicinal plants, bHLH, growth and development, abiotic stress