Genome-Wide Identification and Functional Characterization of the LbaLHCB Gene Family Reveals Tissue-Specific Expression and Salt Stress Response in Lycium barbarum

The <i>LHCB</i> gene family plays a crucial role in light harvesting and photoprotection in plants by encoding key components of the photosystem II antenna complex. The <i>LHCB</i> genes are also involved in salt stress. In this study, we systematically identified and characterized 16 <i>LbaLHCB</i> genes in the economically important medicinal plant <i>Lycium barbarum</i>. 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 <i>LbaLHCB1</i> subfamily showing significant expansion through gene duplication events. qRT-PCR and transcriptome analyses revealed tissue-specific expression patterns, with <i>LbaLHCB1.6</i> exhibiting preferential expression in developing fruits, suggesting its potential involvement in fruit development and quality formation. Under salt stress conditions, the <i>LbaLHCB</i> genes displayed dynamic temporal responses: <i>LbaLHCB1.5</i> was rapidly induced during early stress (1-3 h), <i>LbaLHCB7</i> reached peak expression at mid-phase (6-12 h), while <i>LbaLHCB1.2</i> showed significant downregulation during late stress response (24 h). Promoter analysis identified multiple stress-responsive <i>cis</i>-elements, providing molecular insights into their regulation under abiotic stress. These findings significantly advance our understanding of the <i>LbaLHCB</i> gene family's structural characteristics and functional diversification in <i>L. barbarum</i>, 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.