An Efficient and Stable Agrobacterium-Mediated Transformation System for Rubber Grass ( Taraxacum Spp. )

Abstract BackgroundRubber grass is excellent alternatives to Hevea and ideal model plants for natural rubber research through genetic transformation. However, the transformation is unstable due to the high heterozygosity of rubber grass and the efficiency of the existing transformation system could not well satisfy the needs of the studies on key gene functions of natural rubber biosynthesis.ResultsHere, we report an efficient and stable Agrobacterium-mediated transformation system of rubber grass species using young leaves as explants. An excellent rubber grass species, named as 12-16, that is suitable for tissue culture was selected from a wild germplasm repository collected from Xinjiang. The total regeneration efficiency of 12-16 which cultivated on shoot regeneration medium (Murashige and Skoog (MS) medium plus 1.5 mg/L 6-benzylaminopurine (6-BA) and 0.1 mg/L naphthaleneacetic acid (NAA)) was 100%, and the excellent regeneration shoots reached in 74.1%. Finally, two genes, rubber elongation factors 138 (REF138) and rubber elongation factors 258 (REF258) driven under an enhanced 35S promoter were transformed into 12-16 by Agrobacterium tumefaciens GV3101 mediated genetic transformation. The final transformation efficiency exceeded 20% and the total transformation cycle from leaf explants to hygromycin-resistant seedling lasted approximately 3–4 months.ConclusionsWe provides a highly efficient transformation system based on rubber grass germplasm 12-16 for the introduction of interest genes into rubber grass and provides important technical support for rubber biosynthesis research.