Correlation of HrANR genes and flavonoid accumulation with drought resistance in sea buckthorn (Hippophaerhamnoides subsp. sinensis)

Abstract

Anthocyanidin reductase is one of the key enzyme involved in the synthesis of flavonoids. In order to explore the structure of ANR gene, ANR enzyme expression pattern and flavonoid content under drought stress and their correlation, a HrANR gene identified from RNA-seq data of sea buckthorn was screened and analyzed by bioinformatics soft, the expression patterns of HrANR gene in different tissues and of flavonoid contents in leaves were performed. The results were as follows: (1) The ORF of HrANR gene was 1 017 bp, which encoded 338 amino acids. It was a stable hydrophilic protein, and the homologous protein had significant family and genus characteristics. (2) HrANR gene was expressed in roots, stems and leaves of sea buckthorn under drought stress, but the expression trends were different, with an increase followed by a decrease and then an increase in roots, a continuous decrease in stems, and an increase followed by a continuous decrease in leaves. (3) The flavonoid contents in leaves of sea buckthorn under different levels of stress showed a trend that first increased continuously and then decreased slightly, increased to the highest point after rehydration. The above results indicated that the expression of HrANR gene and the changes of flavonoid content were closely related to the drought resistance of sea buckthorn. The flavonoid content in leaves was positively correlated with drought stress at the beginning of drought stress and negatively correlated with drought stress under severe stress. (4) Leaf expression, stem expression and flavonoid content of HrANR gene were negatively correlated (Pleaf= -0.751, Pstem= -0.934) and root expression was positively correlated with flavonoid content (Proot= 0.444). The above results indicate that the expression of HrANR genes and changes of flavonoid content in sea buckthorn are closely related to drought resistance, and it provides a reference for elucidating the drought resistance mechanism of sea buckthorn.

Keywords

• hippophae rhamnoides subsp. sinensis
• anthocyanidin reductase
• drought stress
• expression pattern
• flavonoid