关键词: 香蕉, 谷胱甘肽过氧化物酶, 序列分析, 非生物胁迫, 生物胁迫, 荧光定量PCR

Abstract: Glutathione peroxidase（GPX）is an important peroxide decomposition enzyme eliminatingreactive oxygen species in plants cells，which is involved in plants response to stress resistance. In thisstudy，a cDNA encoding GPX was isolated from banana root and designated as MaGPX（GenBankaccession No. JX094345）respectively. Sequence analysis indicated that MaGPX was 989 bp in length with an open reading frame of 504 bp predicted to encode 168 amino acids. Amino acid sequence alignment showed that MaGPX shared a typical conserved structure with GPXs from other plant species and showed
high identity with Oryza sativa，Setaria italica，Triticum monococcum，Hordeum vulgare，Zea mays and Citrus sinensis as 85.12%，84.82%，83.93%，83.33%，82.14% and 80.36% respectively. The expression levels of MaGPX in different organs and in banana root under different stresses were analyzed by real-time qPCR. The results showed that MaGPX differentially expressed in different organs examined，with higher level in flowers and roots than that in rhizome，leaves and fruits. In addition，MaGPX expression increased under stresses as salt，waterlogging，drought and in infected by Fusarium oxysporum f. sp. cubense. The results indicate that MaGPX is induced by both biotic and abiotic stress. Lay a foundation for the further research and application of biological function.

Key words: banana, glutathione peroxidase, sequence analysis, abiotic stress, biotic stress, real-timequantitative PCR