The LHCB gene family plays a crucial role in light harvesting and photoprotection in plants by encoding key components of the photosystem II antenna complex. The LHCB genes are also involved in salt stress. In this study, we systematically identified and characterized 16 LbaLHCB genes in the economically important medicinal plant Lycium barbarum. Comprehensive bioinformatics analyses revealed that these genes are unevenly distributed across seven chromosomes, with notable gene clustering on chromosome 11. Phylogenetic analysis classified them into seven distinct subfamilies, with the LbaLHCB1 subfamily showing significant expansion through gene duplication events. qRT-PCR and transcriptome analyses revealed tissue-specific expression patterns, with LbaLHCB1.6 exhibiting preferential expression in developing fruits, suggesting its potential involvement in fruit development and quality formation. Under salt stress conditions, the LbaLHCB genes displayed dynamic temporal responses: LbaLHCB1.5 was rapidly induced during early stress (1–3 h), LbaLHCB7 reached peak expression at mid-phase (6–12 h), while LbaLHCB1.2 showed significant downregulation during late stress response (24 h). Promoter analysis identified multiple stress-responsive cis-elements, providing molecular insights into their regulation under abiotic stress. These findings significantly advance our understanding of the LbaLHCB gene family’s structural characteristics and functional diversification in L. barbarum, particularly in relation to photosynthesis regulation and stress adaptation. The study provides valuable genetic resources for future molecular breeding aimed at improving stress tolerance and fruit quality in this important medicinal crop.

Salt stress is a major abiotic factor limiting wolfberry (Lycium barbarum) growth. As a high-value medicinal and edible crop, wolfberry relies on its carotenoid content, a critical determinant of fruit quality and nutritional value. To elucidate the expression regulatory mechanisms of key genes in the carotenoid biosynthesis pathway under salt stress, this study systematically identified 17 structural genes within the L. barbarum carotenoid pathway using genomic and transcriptomic approaches. Comprehensive analyses were conducted on gene structure, chromosomal distribution, conserved domains, and cis-acting elements. The results revealed that these genes were clustered on chromosomes Chr08 and Chr10 and exhibit strong collinearity with tomato (18 syntenic pairs). Their promoters were enriched with light-responsive (G-box) and stress-responsive (ABRE, DRE) elements. Tissue-specific expression analysis demonstrated high expression in mid-to-late fruit developmental stages (LbaPSY1, LbaPDS) and in photoprotective genes (LbaZEP, LbaVDE) in leaves. Under 300 mM NaCl stress treatment, the genes exhibited a staged response: Early stage (1–3 h): upstream MEP pathway genes (LbaDXS, LbaGGPS) were rapidly induced to supply precursors. Mid-stage (6–12 h): midstream genes (LbaPSY, LbaPDS, LbaZDS) were continuously upregulated, promoting lycopene synthesis and preferentially activating the β-branch (LbaLCYB). Late stage (12–24 h): downstream xanthophyll cycle genes (LbaBCH, LbaZEP, LbaVDE) were significantly enhanced, facilitating the accumulation of antioxidant compounds like violaxanthin and neoxanthin. This coordinated regulation formed a synergistic “precursor supply–antioxidant product” network. This study revealed the phased and coordinated regulatory network of carotenoid biosynthesis genes under salt stress in L. barbarum. It also provided potential target genes for the new cultivar selection with enhanced salt tolerance and nutritional quality.

Carrot (Daucus carota L.) is an important root vegetable crop in the Apiaceae and is widely cultivated around the world. Expansins play crucial roles in the growth and development of plants. Here, a total of 35 carrot expansins were identified from carrot. Sequence alignment and phylogenetic analysis revealed that carrot expansins could be classified into four subfamilies, each with similar exon/intron structures and motif compositions, indicating that carrot expansins were relatively conserved during evolution. Chromosomal localization and gene duplication analysis indicated that DcEXP genes were unevenly distributed across carrot nine chromosomes and had evolved predominantly under purifying selection. Measurements of key agronomic characters of carrots at different developmental stages (30, 60, and 90 days after sowing) indicated significant positive correlations among root fresh weight, aboveground fresh weight, root–shoot ratio, root length, and root diameter. The period from 30 to 60 days after sowing was identified as the primary phase of taproot enlargement. Analysis of spatiotemporal expression patterns revealed that most DcEXP genes were specifically expressed in the taproots, and only one gene, DcEXP18, was specifically expressed in leaves. During the rapid growth period of carrot taproots (30 and 60 days after sowing), the genes DcEXP2, DcEXP3, DcEXP5, DcEXP8, DcEXP11, DcEXP13, DcEXP17, DcEXP19, DcEXP20, DcEXP22, DcEXP26, DcEXP28, and DcEXP33 exhibited high expression levels, suggesting that they played potential important roles in carrot taproot enlargement. These findings will advance our knowledge of the molecular mechanisms underlying expansin regulation of carrot growth and development.