The AnUFGT1 Is Involved in the Anthurium ‘Alabama’ Anthocyanidin Deficiency

Abstract

Anthurium is the second largest tropical flower crop in the world. The international market has urgent demand for anthurium varieties with different spathe colors, which mainly arises from the types and contents of anthocyanin. The flavonoid 3-O-glycosyltransferase (UF3GT) gene is the key enzyme involved in promoting anthocyanin accumulation through glycosylation downstream of the anthocyanin synthesis pathway (ASP). Abnormal functioning of UFGT usually results in a reduction in or loss of anthocyanins. The aim of this study was to reveal the role of one anthurium UFGT gene (AnUFGT1) in ‘Xueyu’ (X), an anthocyanin-deficient mutant of ‘Alabama’. Metabolome analysis was used to analyze the metabolic products in the ASP to determine the possible key link of the anthocyanin deletion mutation. Agrobacterium-mediated transformation of Arabidopsis ufgt and ‘X’ validated the function of AnUFGT1. The results of comparative metabolome analysis of ‘X’ and ‘Alabama’ showed that there was no significant difference in product levels upstream of ASP. The expression levels of AnUFGT1 were significantly greater in ‘Alabama’ than in ‘X’. The overexpression of AnUFGT1 in Arabidopsis ufgt significantly increased its anthocyanin contents. The overexpression of AnUFGT1 in ‘X’, mediated by a new injection method, can only promote the synthesis of trace anthocyanins. These results showed that AnUFGT1 could fully compensate the phenotype of Arabidopsis thaliana ufgt, but only partially compensate the anthocyanidin-deficient phenotype of anthurium mutant X. This difference suggested that anthocyanin-deletion mutations in anthurium ‘X’ are associated with AnUFGT1, but AnUFGT1 is not the only factor. There should be other factors interacting with AnUFGT1 that cause anthocyanin deficiency.