SSH library construction and EST sequence analysis on the development of the calyx of ‘Dangshansu’ pear
The aim of this experiment is to investigate the differentially expressed genes on the development of calyx in the fruitlet period of pear and to provide evidence for the research of molecular mechanisms of its calyx shedding.A subtracted cDNA library about the different expressions between the calyx-setting and the calyx-shedding fruitlet was constructed by using suppression subtractive hybridization(SSH),and the fruitlets of ‘Dangshansu’ pear at the time of calyx shedding were used as materials.A total 200 positive clones were randomly screened out,and 185 expressed sequence tags(ESTs) were identified after PCR and sequencing,in which the EST fragments of more than 100 bp,less than 300 bp and 100-300 bp account for 3%,96% and 1%,respectively.Regulator,protein and related enzyme,which are related to the metabolic process,were found out after BLAST on the NCBI website,accounting for 21%,63% and 16%,respectively.3-isopropylmalate dehydrogenase and N-acyl-L-amino acid amidohydrolase were obtained on the Gene Ontology website and it was presumed that they were important related enzymes in the metabolic process of calyx development in the fruitlet period of ‘Dangshansu’ pear.