Research progress and prospect of β-carotene hydroxylase gene mediating plant carotenoid metabolism in response to abiotic stress.

Carotenoid metabolism plays a significant role in plants response to abiotic stress. The β-carotene hydroxylase gene (BCH) is an important gene located downstream of the carotenoid metabolic pathway. Its main function is to hydroxylate β-carotene to form zeaxanthin, which is the direct valve regulating the carotenoid xanthophyll cycle and also an important controller in the upstream of ABA synthesis. Most carotene components contain a molecular structure with conjugated double bonds, which determines that they have a powerful antioxidant function. When the BCH gene is overexpressed, Reactive oxygen species (ROS) can be quenched, Non-photochemical quenching (NPQ) is elevated, the excess oxidation energy is released in the form of heat, thereby playing a role in protecting plant tissues and cells. At the transcriptional regulation level, a large number of positive and reverse regulatory transcription factors have been screened out to regulate the BCH gene. In addition, miRNA directly or indirectly regulates the BCH gene through transcription factors. However, there are few reports on the research of the BCH gene at the level of protein translation modification. In summary, this article reviews the functional research, transcriptional regulation and miRNA regulation progress of the BCH gene, and at the same time makes prospects at the protein translation modification level (ubiquitination and phosphorylation), with the aim of laying a foundation for in-depth exploration of the BCH gene's function at the epigenetic level.