Ectopic expression of thePttKN1gene in coleus (Solenostemon scutellarioides)

Abstract

The foreign PttKN1 gene was introduced into the genome of coleus (Solenostemon scutellarioides) using the floral dip method mediated by Agrobacterium tumefaciens. The seeds that generated from the dipped mother plant were screened on MS medium with a kanamycin concentration of 100 mg l–1. Those kanamycin-resistant plantlets displayed various morphological alterations different from the wild type plant. Among those morphological alterations, the most were appeared in the local of the transgenic plant, including (1) the leaf morphological changes: knots formation, accidented leaf surface, lobed leaf, twisted and asymmetric leaf, etc. (2) the floral morphological changes like receptacle and flower color. Moreover, alterations throughout the plant were also observed such as clustered plant, plant with whorled phyllotaxy or faded leaf coloration, etc. Among them, the altered morphologies of whorled phyllotaxy and faded leaf coloration were scarcely appeared in other PttKN1 gene transformants. The results of PCR and PCR-Southern showed that the foreign PttKN1 gene had integrated into the genome of coleus, and was responsible for the above morphological alterations. Further comparison of the anthocyanin content in transgenic and wild type coleus showed that the biosynthesis of anthocyanin was inhibited in the faded-anthocyanin coleus.