Background and Objective: Histaminase (diamine oxidase) in mammals, including human, oxidize putrescine, cadaverine, agmatine and histamine. Plant histaminases, especially from Fabaceae family have a better and faster catalytic activity than animal counterparts. Recently, plant histaminases are being used as medicine to treat diseases such as hypotension, vascular headaches, impaired bowel function, respiratory symptoms, allergic infectious swelling, cancer treatment and anaphylactic cardiac shock. The aim of this study was to isolate and clone a chickpea histaminase gene to be expressed in plants, producing the recombinant protein.
Materials and Methods: The RNA of 5 seven-day old etiolated chickpea (Cicer arietinum L var grit) seeds was extracted. A cDNA encoding a histaminase gene was synthesized, using reverse transcriptase enzyme. Next, histaminase gene was amplified by PCR, using specific primers. Finally cDNA was cloned in the pTZ57RT cloning vector and bioinformatics analysis was performed.
 
Results: In this study, the encoding amine oxidase copper-containing cDNA from the pea was isolated and cloned, using molecular techniques. Results of this study showed that the full length of the cDNA was 2013 bp. The histaminases open reading frame (ORF) encoded a protein of 670 amino acids with a molecular mass of 75.7 KDa. Chickpea histaminase protein sequence shared 99% and 85% similarity to Cicer arietinum(CAAO), and Pisumsativum (PSAO), respectively.
Conclusion: In general, chickpea histaminases can be introduced to plants to produce new drugs. Plant recombinant expression may hold great promise to increase the yield as well as quality of plant made histaminase.