들잔디의 효율적인 형질전환 조건 검토 및 환경스트레스 내성유전자를 도입한 GM들잔디의 제조

Abstract

Zoysiagrass (Zoysia japonica Steud.) is one of the most popular turfgrass species in many countries. According to the use of this turfgrass increases, there is an increase in the demand for genetic improvement of the species. An efficient transformation protocol, using mature seed-derived callus cultures and Agrobacterium-mediated transformation, has been developed for the production of transgenic zoysiagrass. In order to optimize transformation conditions, several factors such as cultivars for selecting of embryogenic callus as explant, infection time, concentration of Agrobacterium suspension, co-cultivation period, concentration of phosphinothricin when selection, influencing on transformation efficiency of zoysiagrass were evaluated. Embryogenic callus from 'Ducchang' is more suitable than that of from 'Misung' for efficient transformation. An appropriate concentration (O.D600= 0.1-0.2) of Agrobacterium and 24 hour of infection time showed a higher level of infection. Continuous selection by combination of high and low concentrations of selection agent produced transgenic plants with low escapes. Using this transformation system, abiotic stress-related genes, Annexin1, ATHG1, ATPG7, and ATPG8 were introduced into zoysiagrass. Transgenic plants were confirmed by genomic PCR and Southern blot analysis. The transformation efficiencies for Annexin1, ATHG1, ATPG7, or ATPG8 ranged from 0.24 to 3%. The transgenic plants overexpressing Annexin1 gene showed enhanced oxidative, salt, and drought tolerance compared to wild type zoysiagrass. The established transformation system will promote the development of genetic improvement of the zoysiagrass.