Clone of G6PDH Gene(GND)from Nostoc flagelliforme and Differential Expression under Drought Stress
LIU Yang;YAN Fengkun;DING Miaomiao;LI Xiaoxu;WANG Lingxia;YUE Sijun;LIANG Wenyu;School of Life Sciences,Ningxia University;School of Agriculture,Ningxia University;Key Lab of Ministry of Education for Protection and Utilization of Special Biological Resources in Western China;
GNDcoded glucose 6-phosphate dehydrogenase(G6PDH)is a key enzyme in the pentose phosphate pathway.In order to understand molecular information of GND and mechanism in response to drought stress,we cloned GNDby designed specific primers based on sequences of homologous cyanobacteria species.The sequence was analysed by bioinformatics methods,and the differential expression of GNDand G6 PDH activities of N.flagelliforme under drought stress were also discussed.The results indicated that:(1)the full length of GNDis 1 431bp(GenBank access number:KX553955).Nucleotide sequence and deduced amino acid sequences of GNDfromN.flagelliforme were similar to that of N.punc-tiforme PCC 73102 with similarities above 96%and 98%,respectively.Ile is the most hydrophobic in site26 and 27,but Arg is the most hydrophilic in site 302.Thr,Ser and Tys have 19,18 and 5phosphorylation sites,respectively.Secondary and tertiary predicted structures of G6 PDH were made up ofαhelix,βsheet,βturn and random coil.(2)GND was expressed in E.coil then a 47.23 kD heterologous protein was observed and tested by MALDI-TOF-TOF/MS.(3)GND expression at the transcription level and G6 PDH activity were all gradually increased under drought stress.The results provided a foundation for further research in GNDexpression and regulation of N.flagelliformein response to drought stress.