Selection of suitable lily cultivars by using needle agroinfiltration for blue flower production

Lily is one of the most important flower crops that it lacks blue-purple flowers due to the absence of the flavonoid 3’,5’-hydroxylase gene and deficiency of delphinidin accumulation. In this study, the possibility of transient expression of F3ʹ5’H gene and delphinidin accumulation were examined by agroinfiltration method in petals of six commercial lily cultivars. Three sizes of the flower buds and new blossomed flowers were harvested and measured for anthocyanidin content by the high-performance liquid chromatography to determine the appropriate stage for agroinfiltration. Then, the petals were infiltrated at the best stage with two vectors namely pBI121-35S carrying only F3ʹ5’H and pBIH-35S-Del2 harbouring F3ʹ5’H, DFR and ANS genes. The results indicated that the largest buds and new blossomed flowers showed the highest contents of anthocyanins in all subjected cultivars. Therefore, new blossomed flowers were injected with two different expression vectors. The HPLC analyses showed the highest delphinidin contents were detected in the two cultivars ‘Brindisi’ and ‘Gaucho’ by 77.63 and 43.60 μg g−1 fresh weights, respectively, when they were infiltrated with the pBIH-35S-Del2 construct. Real-Time PCR confirmed the results of anthocyanin measurements properly. Consequently, these two cultivars were selected as the appropriate hosts for lily stable transformation programmes.Abbreviations: ANS: Anthocyanidin synthase; CaMV: Cauliflower mosaic virus; CHS: Chalcone synthase; CTAB: Cetyl trimethyl ammonium bromide; DFR: Dihydroflavonol 4-reductase; DHK: Dihydrokaempferol; DHM: Dihydromyricetin; F3ʹH: Flavonoid 3’-hydroxylase; F3ʹ5’H: Flavonoid 3’, 5’-hydroxylase; FW: Fresh weight; GUS: β-glucuronidase; HPLC: High performance liquid chromatography; OD: Optical density; T-DNA: Transfer deoxyribonucleic acid.