Keywords: 
• forest tree breeding /
• Salix matsudana /
• Sedum alfredii /
• cDNA library /
• yeast /
• salt tolerance /
• cadmium tolerance /
• grouth curves

Abstract: To provide a basis for studying a new stress－related gene of Salix matsudana and Sedum alfredii，the salt－stress induced full－length cDNA Library of Salix matsudana and the cadmium－stress induced，full－length cDNA Library of Sedum alfredii were constructed using an improved switching mechanism at 5 end of RNA transcript （SMART） method. The full－length cDNA fragment was linked to the yeast vector pYES2.1，and then the linked product was transferred onto the yeast INVSc1. Concentrations of NaCl and cadmium stress were utilized to construct yeast transformants library. Growth performance of yeast recombinants and their control with an empty vector were tested under the control（0），high salinity （1 molL-1 NaCl），or high cadmium（150 molL-1 cadmium） conditions. Also，a bioinformatics analysis and real－time polymerase chain reaction （PCR） were conducted. Results for the yeast transformants library revealed two positive transformants with a tolerance of 1.709 molL-1 NaCl and two positive transformants with a tolerance of 0.123 mmolL-1 cadmium. Growth rates of the recombinants with cDNA protein under the non－stress condition indicated that the expression of cDNA was not deleterious to yeast growth. Compared to the control，yeast cells expressing cDNA showed a shorter lag period when transferred to a medium containing high salinity and high cadmium. The results of a bioinformatics analysis and real－time PCR showed that the No. 6 salt－tolerant transformant gene was a salt－resistant related gene. This study showed that the expression of cDNA could confer salt and cadmium tolerance in yeast and provided an important tool for establishing an efficient system of stress－resistant gene cloning using the yeast INVSc1.［Ch，9 fig. 12 ref.］