Melatonin strongly enhances the Agrobacterium- mediated transformation of carnation in nitrogen-depleted media

Abstract

With the rising demand for new cultivars of carnation, efficient transformation protocols are needed to enable the bioengineering of new traits. Here, we established a novel and efficient Agrobacterium-mediated transformation system using callus as the target explant for four commercial carnation cultivars. Leaf-derived calli of all cultivars were inoculated with Agrobacterium tumefaciens strain LBA4404 containing the plasmid pCAMBIA 2301 harboring genes for β-glucuronidase (uidA) and neomycin phosphotransferase (nptII). Polymerase chain reaction (PCR) and histochemical assays confirmed the presence of uidA and β-glucuronidase (GUS), respectively in transgenic shoots. The effect on transformation efficiency of medium composition and the presence of antioxidants during inoculation and co-cultivation was investigated. The transformation efficiency was increased in Murashige and Skoog (MS) medium lacking KNO3 and NH4NO3, and also in MS medium lacking macro and micro elements and Fe to 5% and 3.1% respectively, compared to 0.6% in full-strength medium. Transformation efficiency was increased dramatically to 24.4% across all carnation cultivars by the addition of 2 mg/l melatonin to nitrogen-depleted MS medium. Shoot regeneration was also doubled in this treatment. The establishment of this efficient and reliable transformation protocol can advance the development of novel carnation cultivars through molecular breeding approaches.

Oliviculture and Viticulture Crop Byproducts Use for Peat Partial Substitution for Carnation Production

“…Nowadays, floriculture is a dynamic, global and fast-growing industry [24], and at the wholesale market, carnation (Dianthus caryophyllus L.) is one of the most popular cut flowers, with a rich flower color and form, ranking next only to rose [25]. A large breeding research implemented to date, as indicated by the increased number of carnation cultivars worldwide, has demonstrated the carnation's appealing and unique qualities, including different flower colors, sizes and shapes; enhanced fragrance; resistance to susceptibility; increased yield; and extended vase life [26]. The increased needs for carnation production mirrored the high research interest for the evaluation of different growing media for carnation production [27][28][29].…”