Maasr1 Expression And Functional Analysis In Different Stage Banana Postharvest

Banana is a kind of typical respiration climacteric fruit. It contributes to establish a new preservation technology to study the mechanism of fruit ripening by molecular biological research, which has important theoretical and practical meanings to regulate its ripening and to study the mechanism of ripening. ASR(abscisic acid, stress and ripening inducible)genes are recently discovered from plants. ASR genes are continually isolated and characterized from various plant species. Though its physiological role remains unclear, it has been reported that the expression of ASR gene results from several stresses including cold, osmotic pressure, abscisic acid treatment, and in the process of fruit ripening. Maasr1 gene belongs to ASR gene family. Our laboratory had already obtained the full length sequence cDNA of Maasr1 by screening cDNA library of banana fruit. The results of chip analysis and Northern showed that it might be associated with fruit ripening,so it was very necessary to investigate it further.To obtain some useful information for further research on Maasr1 function, we analyzed the physical and chemical characteristics of Maasr1 and predict structure and function by bioinformatical methods. Protparam was used to analyze the physical and chemical characteristics of Maasr1 product protein, such as composition of amino acid sequence, molecular mass,isoelectric point; InterProScan and Scanprosite were used to research domains and motif; Predictprotein was used to predict the secondary structure and relative solvent accessibility; ClustalW was used to align multiple sequence; Psort ,SubLoc and Protfun were used to predict subcellular location and protein function, respectively. The results showed that this protein was instable, Mr 16263.8Da, pI 5.99, with strong hydrophilicity, located to both cytoplasm and nucleus. The deduced amino acid sequence was rich in Glu, Ala, His, Lys, contained various protein kinase phosphorylation site and a N-myristoylation site. The secondary structure was primarily composed of Alpha helix. Maasr1 seemed to function in processes of transcription,transcription regulation and stress response.we treated banana fruits with exogenous ethylene and ethylene absorbed reagent and measured the respiratory rate , ethylene production rate,ABA content of pulp and PG activities of pulp.The results showed that exogenous ethylene raised obviously the respiratory rate , ethylene production rate,ABA content of pulp and PG activities of pulp and promoted the fruits ripening. Treatment with ethylene absorbed reagent lowered...