Effect of exogenous nitric oxide on cloning and expression of AOX gene and cyanide resistant respiration in Jiashi muskmelon

The effects of exogenous nitric oxide fumigation on the expression of AOX gene and the cyanide resistant respiratory pathway in Jiashi muskmelon during the storage were investigated. Jiashi muskmelon ( Cucumis melo L.) as test materials were fumigated with 60 μL/L NO for 3 hours in sealed boxes, not filled with NO gas as control, and then stored at ( 5 ± 0.5) ℃ for49 days.According to the muskmelon genome database, primers were designed by EST, and the full length sequence of Jiashi muskmelon AOX gene was cloned.The c DNA fragment exhibited high homology to the alternative oxidase of other species and could be referred to as Cm AOX.The full-length c DNA sequence of AOX gene was obtained by splicing.The full length c DNA of Cm AOX was 1300 bp in size with a 1042 bp open reading frame ( ORF) , and 346 amino acids was encoded. The predicted molecular weight of Cm AOX was 39606.6 Da, and the isoelectric point was 9.00.The accession number of Cm AOX in Gen Bank database was KM273124. The cyanide resistant respiration rate of Jiashi muskmelon with the treatment of 60 μL/L NO was found to be significantly higher than that of the control. Real-time PCR showed that the expression of Cm AOX with the NO treatment of Jiashi muskmelon was significantly higher than that of control muskmelons during the whole storage period.The NO treatment could induce the up regulation of AOX gene in Jiashi muskmelon during the storage.It was suggested that the effect of NO treatment on the expression of AOX gene of Jiashi muskmelon may be closely related to cyanide resistant respiration regulation during the storage.