The Techniques Of Directive Cultivation For Alkali-resistance And Lignin Decreased Eucalyptus Grandis×E.urophylla

Eucalyptus is belonged to Myrtaceae Eucalyptus and cultivated in south andsouthwest of China. Eucalyptus is one of the main raw materials in pulping andpaper-making, while it contains much of lignin which has important effect on thequality of the pulp.4-coumaric acid coenzyme A ligase (4-coumarate: CoA ligase,4CL) is one of the key enzymes in lignin biosynthesis, and can reduce the content oflignin effectively by inhibiting the expression of4CL genes. In this paper, the plantexpression binary vector contained antisense4-coumarate:CoA ligase (anti-4CL1)gene from Populus tomentosa fused with glycine rich protein (GRP1.8) promoterwas transformed to Eucalyptus grandis×E.uroophylla with leaf disc transformationmediated by Agrobacterium tumefaciens. Nine positive transgenic plants wereobtained by kanamycin resistant selection and PCR amplification identification. Theresults of enzyme activity determination showed that the4CL1enzyme activity oftransgenic plants in tissue culture decreased up to44%compared with wild-typeplants. The content of klason lignin in transgenic seedlings in greenhouse wasdecreased by16%.In China, cold injury is a major factor for limiting the natural distribution of plantsand planting zone. Cultivating new species of Eucalyptus with resistance to lowtemperature benefited to plant Eucalyptus in north area. Cu, Zn-superoxidedismutase1(Cu, Zn-SOD1) is a kind of metal enzyme for scavenging the superoxideanion radical. The overexpression of Cu, Zn-SOD1in plants by gene engineeringcould enhance the resistance to low-temperature. In this paper, the plant binaryexpression vector constructed by activating the Cu, Zn-SOD1from Eucalyptusgrandis×E.uroophylla with the CaMV35S promoter was improted to Eucalyptusgrandis×E.uroophylla. Ten strains of positively transgenic plants were preliminarilyidentified by kanamycin resistant selection and PCR amplification, which suggestedthat the transduction of Cu, Zn-SOD1gene to Eucalyptus grandis×E.uroophylla wassucceed. After hardiness detection, No.40trangenic plant was selected for stronger cold resistance. It can be completely recovered72h later after5h in-13.1℃coldtraining.Eucalyptus is one of the main raw material for paper-making. In order to get thehigh-quality eucalyptus with low-content of lignin and resistance to low-temperature,binary plant expression vector was constructed with Cu, Zn-SOD1gene fromEucalyptus grandis×E.ophylla and pBD-anti-4CL1from Populus tomentosa andconducted into Eucalyptus grandis×E.ophylla with leaf disc transformation mediatedby Agrobacterium tumefaciens. Eight positively transgenic plants were selected outby kanamycin resistant selection and PCR amplification. After hardiness detection,the stronger cold resistance transgenic plants No.52was choosed. It can becompletely recovered72h later after5h in-13.1℃cold training.