Phenotypic and molecular analysis of seabuckthorn accessions reveal promising genotypes and candidate genes associated with micronutrients

Seabuckthorn (genus Hippophae L., family Elaeagnaceae), rich in vitamin C, anthocyanin, and minerals including iron (Fe) and zinc (Zn), is a potential candidate to combat micronutrient malnutrition. In this study, high diversity for Fe (39.7-341.5 mg kg^− 1), Zn (0.6–12.7 mg kg^− 1), and vitamin C (40–595 mg 100 g^− 1) was found in 70 accessions across Gilgit region of northern Pakistan (2444–3172 m.a.s.l). Orange/yellow fruit colours abundantly found at lower altitudes showed the highest Fe concentration (250.03 ± 61.5 mg kg^− 1). Despite high phytic acid levels (785–1811 mg kg^− 1), low ratios for PA: Fe < 0.8, PA: Zn < 0.04 suggested high bioavailability. 18 HrAKR genes were identified, with 10 confirmed by PCR in the studied accessions. Three HrAKRs were consistently expressed, while seven were differentially expressed across tissues suggesting role in nutrient metabolism. Accessions of a higher altitude region (Sost) combined higher micronutrient levels, greater bioavailability, and stronger AKR expression. These findings highlight potential of HrAKR-associated traits for improving nutritional value of seabuckthorn through gene pyramiding. Further functional studies are needed to identify the function of each HrAKR gene to enable molecular marker development for seabuckthorn breeding programs.