Efficient regeneration and transformation of Spathiphyllum cannifolium

Abstract

An efficient and stable transformation system was developed based on embryogenic cell suspension culture by Agrobacterium tumefaciens-mediated method in Spathiphyllum cannifolium. Embryogenic calli induced from leaves on MS medium with 1.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/L thidiazuron were incubated in liquid medium with identical growth regulators for suspension cultivation. The plantlet regeneration rate of embryogenic suspension cell aggregates (ESCAs) incubated on MS medium achieved 100 %. The ESCAs were transformed using A. tumefaciens strain EHA105 harboring a vector pCAMBIA1301 containing the β-glucuronidase (gusA) reporter gene and the hygromycin phosphotransferase II (hpt II) selection marker gene. The optimized transformation conditions were as follows: infiltration of ESCAs with Agrobacterium for 10 min under 60 kPa vacuum pressure, followed by co-cultivation on medium containing 200 μM acetosyringone for 3 days. In total, 858 plants were regenerated from 1200 infected ESCAs. Analyses of randomly selected regenerated plants by GUS assays, PCR and dot blot showed that 91.30 % were transgenic. Southern blot analyses revealed that the copy number of T-DNAs integrated into the genome ranged from one to three. This newly developed transformation system provides a basis for the future development of genetic engineering techniques to improve flower color and enhance the disease resistance of peace lily.