Establishment Of PeDWF4-Sainfoin And PeDWF4-Perilla Transgenic Lines And Analysis Of PeCPD-potato Transgenic Lines

Brassinosteroids (BRs) is a new type of steroid phytohormone, playing important roles not only in the regulation of normal growth and development of the whole plant, but also in improvement of the ability of plant resistance to environmental stress, and crop growth and yield. Both DWF4 and CPD genes encode the key enzymes involved in BRs biosynthesis, and PeDWF4 and PeCPD are cloned from P.euphratica and are homologous to Arabidopsis DWF4(AtDWF4) and CPD (AtCPD). Sainfoin is a kind of perennial high-quality forage. Perilla is a medicinal and edible plant, and potato is the world’s fourth largest food crops. In this study, PeDWF4 gene was transformed into genomies of sainfoin and perilla by Agrobacterium tumefaciens-mediated genetic transformation method, and PeDWF4-sainfoin and PeDWF4-perilla transgenic lines were preliminarily established. In addition, the genetic stability of PeCPD-potato transgenic lines that were previously established by our group was analyzed. Aims to: 1) better understand the functions of PeDWF4 and PeCPD through physiology and biochemistry, genetics and molecular biology analysis of transgenic lines; 2) explore the possibility to obtain resistant or quality improved sainfoin and perilla through transformation. We found that 1) the optimum medium for direct adventitious shoot regeneration from hypocotyl was MS+4.0mg/L 6-BA+0.1 mg/L NAA for sainfoin and MS+1.Omg/L 6-BA+1.Omg/L IAA for perilla, using which the regeneration rate of sainfoin and perilla are up to 97% and 75.6%, respectively. Compared with the previous study, the regeneration rate of sainfoin was increased by 15% and the regeneration cycle of perilla was shortened by 10 days; 2) best rooting medium for sainfoin was 1/2 MS+1.0 mg/L IBA+0.3 mg/L NAA+0.1 mg/L 6-BA,with a rooting rate up to 60%; 3) 8 PeDFFF4-Sainfoin and 7 PeDWF4-Perilla transformants were confirmed by PCR. The suitable conditions for sainfoin and perilla transformation are infection 12min+Hyg 15 mg/L+Cef 400 mg/L, and infection 20 min+Hyg 7.5 mg/L+200 mg/L Cef, respectively. However, due to the difficulty of rooting and limited time, complete transgenic plants have not been obtained; 4) analysis of the phenotypes, photosynthesis, tube yield and the contents of tube starch and VC of the T3 and T4 generation PeCPD-potato transgenic lines revealed that compared with wild type, some line (P9) of them showed an increase in tube yield as well as starch and VC (content of starch is up to 193.09 mg/g and VC 27.84mg/100g). The results indicate that to transform other crops with PeCPD possibly has certain potential application value.