Cloning and Function Analysis of 6-Phosphogluconolactonase Gene MdPGL4 in Apple Fruits
6-Phosphogluconolactase(PGL)is a key enzyme in the pentose phosphate pathway,which plays important roles in sugar metabolism and plant immunity.Based on the previous transcriptome results,MD01G1226300,which had strong response to apple ring rot,was selected and cloned,and its function was analyzed.The results showed that the spot extension area of'Luli'apple was significanty smaller than that of its parents'Royal Gala'and'Mato'after inoculated with Botryospheria dothidea for 6 days.qRT-PCR analy-sis showed that MD01G1226300 was strongly induced,and the expression level in'Luli'was significantly lower than that in'Royal Gala'and'Mato'.Results of bioinformatics analysis showed that the full length of MD01G1226300 cDNA was 762 bp,and it encoded 253 amino acids.MD01G1226300 was a stable hydrophil-ic protein with the molecular weight of 28.04 kDa and the theoretical isoelectric point of 5.85,which belonged to SugarP_isomerase superfamily with 6 possible active sites and no transmembrane domain and was located in the extracellular region;its tertiary structure was mainly composed of α helix and β folding.Through homol-ogous sequence analysis,MD01G1226300 was named MdPGL4,which had the closest evolutionary relation-ship with PbPGL4 of pear with the homology of amino acid sequence as 70.13％.The resistance to B.dothidea and the expression level of resistance-related genes were significantly decreased in the MdPGL4-overexpression transgenic apple compared with the control,which indicated that MdPGL4 negatively regulated the apple re-sistance to B.dothidea.These results enriched the theoretical system of PGL family genes response to biotic stress in apple,and provided reference genes for molecular mechanism analysis of apple disease resistance and creating new germplasms resistant to disease by improving genetic characters.
AppleMdPGL4Apple ring rotGene cloneFunction identification
万方数据
维普
