Objective This study aims to clone the LbbHLH94-like gene from Gouqi (Lycium barbarum), analyze its spatiotemporal expression, stress and hormone response patterns, and clarify its regulatory function in carotenoid biosynthesis, so as to provide a theoretical basis for revealing the molecular mechanism of goji berry fruit quality formation. Methods Using Lycium barbarum cv. ‘Ningqi 1’ as material, we employed techniques such as PCR and qRT-PCR to clone and analyze the expression patterns of LbbHLH94-like in different tissues, fruit developmental stages, abiotic stresses and exogenous hormone treatments. The overexpression vector was constructed and transformed into goji plants, and the expression of key genes, enzyme activities and total carotenoid content in carotenoid metabolism were determined. Results The LbbHLH94-like gene was successfully cloned, with an 888 bp open reading frame encoding 296 amino acids, and the sequence was identical to the genome reference sequence. This gene showed obvious spatiotemporal specificity, with the highest expression level at fruit ripening stage. It responded to high and low temperature, salt, drought stresses as well as 6-BA, IBA and GA₃ induction, showing a general pattern of promotion at low concentration and inhibition at high concentration. Overexpression of LbbHLH94-like significantly up-regulated the expression of PDS, enhanced the enzyme activities of PSY and PDS, inhibited the expression and enzyme activity of CCD4, and remarkably increased total carotenoid content in fruits. Conclusion LbbHLH94-like is a key positive regulator of carotenoid biosynthesis in goji berry, and also participates in abiotic stress response and hormone signaling. The results provide important gene resources and theoretical support for quality improvement and precise molecular breeding of Lycium barbarum.

Lycium barbarum L.  /  LbbHLH94-like gene  /  expression analysis  /  abiotic stress  /  carotenoid biosynthesis  /  molecular regulation