With the development of planta genetic engineering, more emphases have been laid on convenient and high efficient genetic transformation methods. And transformation without tissue culture is a prospective direction of it. In this paper, traditional transformation methods and the methods of non-tissue culture were summarized. With the exploration and application of Arabidopsis transformation mechanism, with the use of ion beam-mediated transfor- mation invented by Chinese scientists and the development of other transformation methods, transformation methods without tissue culture and planta genetic engineering could be improved rapidly.
We have developed a large number of exocrine glands on liquorice leaves and facilitated polysaccharide secretion. Liquorice polysaccharide possesses stronger bound water affinity to gaseous water compared with sucrose and glucose. Our results show that the bound water affinity of liquorice polysaccharide to gaseous water is 49.75% higher than glucose （p〈0.01）. With N^＋ implantation （total dosage of 4.68×10^16 ions/cm^2 and energy of 20 keV） into dry liquorice seeds, both the bound water affinity to gaseous water and the bound water content of dry liquorice leaf can be significantly increased 30.24% （p 〈 0.01） and 36.51% （p 〈 0.01） respectively compared with the sham-irradiated seeds. Meanwhile, with these parameters chosen for N^＋ implantation into dry liquorice seeds, the leaf polysaccharide content under water stress （ψw=-1.5 MPa） can increase significantly （p 〈 0.05） and the plant growth can also improve significantly （p 〈 0.05）.
