抄録
Basic helix–loop–helix (bHLH) transcription factors are widely present in plants and play a central role in adaptation to abiotic stresses. However, functional studies of bHLH family members in potato remain limited, which restricts their application in stress-resilient breeding. In this study, the potato StFBH3 gene was selected as the research focus to elucidate its role and molecular regulatory mechanism in stress response. StFBH3 overexpression lines were generated through gene cloning and vector construction, and their expression and functional characteristics were analyzed under osmotic stress, high salinity, and exogenous abscisic acid treatments. Gene expression patterns were assessed by qPCR, while physiological and biochemical traits, including chlorophyll content, root length, relative water content, and superoxide dismutase (SOD) activity, were measured. The results showed that StFBH3 was highly expressed in roots and leaves and significantly induced under multiple stress conditions. Overexpression lines exhibited enhanced tolerance to osmotic and salt stress, as evidenced by higher relative water content, chlorophyll content, and SOD activity compared with controls. At the molecular level, StFBH3 likely exerts positive regulatory effects by modulating downstream genes such as KAT1. These findings demonstrate that StFBH3 plays a positive regulatory role in potato adaptation to abiotic stress and provide new theoretical insights and potential molecular targets for elucidating the mechanisms of bHLH transcription factors and improving stress resistance through genetic breeding.
