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

## TL;DR

This study identifies and characterizes 16 LbaLHCB genes in Lycium barbarum, revealing their roles in fruit development and response to salt stress.

## Contribution

The study provides new insights into the functional diversification and stress response mechanisms of the LbaLHCB gene family in Lycium barbarum.

## Key findings

- LbaLHCB genes show tissue-specific expression, with LbaLHCB1.6 preferentially expressed in developing fruits.
- LbaLHCB genes exhibit dynamic temporal responses to salt stress, with distinct expression patterns at different stress stages.
- Promoter analysis identified stress-responsive cis-elements, offering molecular insights into gene regulation under abiotic stress.

## Abstract

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.