Cloning And Expression Analysis Of PuRGL2Gene Encoding Della Protein And Dwarf-Related Genes From The Pear Dwarfing Mutants

The pear dwarfing mutant was used in this experiment, different growth regulators were treated to the experiment materials and collect the leaves, The gene which encoding DELLA named PuRGL2was cloned by PCR and rapid-amplification of cDNA end(RACE). Research the mutation type of the pear dwarfing mutant with semi-quantitative PCR, we study on the genetic relationships of8pear cultivars with SRAP markers. The result as follows;The different plant growth regulators have effect on the pear dwarfing mutant. We used the200,250,300mg·L-1GA3,50mg·L-1IAA,1000mg·L-1PP333treat on current growth of the pear dwarfing mutant, the results showed that GA3treatment effect was better than IAA and PP333treatment, and the optimum concentration of GA3was250mg·L-1. But the pear dwarfing mutant was insensitive to IAA. We conjecture the pear dwarfing mutant was GAs-deficient mutant.A whole cDNA sequence of DELLA protein was cloned from the pear dwarfing mutant, which was named PuRGL2. The full-length of PuRGL2was1755bp, encoding584amino acids. Homology analysis results that PuRGL2shared respective homologies with MdRGL2b、RGL2b、 RGL2a、MdRGL2、GAI2as99%、99%、98%、98%、98%, and successfully constructed the plant expression vectors of PuRGL2.The expression intensity of GA20-ox, PuRGLl, PuRGL2show that:GA20-ox gene expression level was lower than that of PuRGL1, PuRGL2. This indicated that the plant height related with GA20-ox gene.SRAP markers was used to analysis genetic relationships of8Pear cultivars. UPMGA method was used to make cluster analysis and the result showed that the pear dwarfing mutant and ’xiehuantian’ has a closed relationship.