Molecular mechanisms of flavonoid accumulation in germinating common bean (Phaseolus vulgaris) under salt stress

Qi Zhang; Guangyue Zheng; Qi Wang; Jixing Zhu; Zhiheng Zhou; Wenshuo Zhou; Junjie Xu; Haoyue Sun; Jingwen Zhong; Yanhua Gu; Zhengong Yin; Yan-Li Du; Ji-Dao Du

doi:10.3389/fnut.2022.928805

Molecular mechanisms of flavonoid accumulation in germinating common bean (Phaseolus vulgaris) under salt stress

Front Nutr. 2022 Aug 29:9:928805. doi: 10.3389/fnut.2022.928805. eCollection 2022.

Authors

Qi Zhang¹, Guangyue Zheng¹, Qi Wang¹, Jixing Zhu¹, Zhiheng Zhou¹, Wenshuo Zhou¹, Junjie Xu¹, Haoyue Sun², Jingwen Zhong¹, Yanhua Gu¹, Zhengong Yin³, Yan-Li Du¹, Ji-Dao Du^{1

4}

Affiliations

¹ Legume Crop Laboratory, Agricultural College, Heilongjiang Bayi Agricultural University, Daqing, China.
² Qiqihar Branch of Heilongjiang Academy of Agricultural Sciences, Qiqihar, China.
³ Crop Resources Institute of Heilongjiang Academy of Agricultural Sciences, Harbin, China.
⁴ National Cereals Technology Engineering Research Center, Daqing, China.

Abstract

Flavonoids are important secondary metabolites, active biomolecules in germinating beans, and have prominent applications in food and medicine due to their antioxidant effects. Rutin is a plant flavonoid with a wide biological activity range. In this study, flavonoid (rutin) accumulation and its related molecular mechanisms in germinating common bean (Phaseolus vulgaris) were observed at different time points (0-120 h) under salt stress (NaCl). The rutin content increased from germination onset until 96 h, after which a reducing trend was observed. Metabolome analysis showed that salt stress alters flavonoid content by regulating phenylpropanoid (ko00940) and flavonoid (ko00941) biosynthesis pathways, as well as their enzyme activities, including cinnamyl-alcohol dehydrogenase (CAD), peroxidase (POD), chalcone isomerase (CHI), and flavonol synthase (FLS). The RNA-seq and quantitative real-time PCR (qRT-PCR) analyses also showed that these two pathways were linked to changes in flavonoid content following salt treatment. These results reveal that salt stress effectively enhanced rutin content accumulation in germinating beans, hence it could be employed to enhance the functional quality of germinating common beans.

Keywords: common bean; flavonoid biosynthesis; flavonoids (rutin) content; germinating; mechanism; phenylpropanoid biosynthesis; salt stress.