Characterization of an NDR1/HIN1-like gene from mango (Mangifera indica L.) and its expression under postharvest and stress treatment

The NDR1/HIN1-like (NHL) gene family plays important roles in response to pathogen infection, growth and stress response of plants. In this study, a full-length NHL1 genes, named as MiNHL1, were isolated from Mangifera indica L. based on modified rapid amplification of cDNA ends (RACE) technique. The expression level of MiNHL1 gene in different tissues of Mangifera indica L. was studied by semi-quantitative RT-PCR and quantitative RT-PCR methods. Sequence analysis showed that the length of MiNHL1 gene was 1019 bp, contained an open reading frame (ORF) of 666 bp, encoding 222 amino acids, the molecular weight of protein was 25.16 kDa, the isoelectric point was about 9.62, and have a late embryogenesis abundant protein LEA-2 superfamily. Phylogenetic studies suggested that MiNHL1 is related to Arabidopsis NHL21 protein. Expression analysis showed that MiNHL1 gene expressed in various tissues, including vegetative and reproductive tissues, but MiNHL1 gene higher expressed in mature stems and mature fruits. qRT-PCR results demonstrated that MiNHL1 gene was significant repressed by oxalic acid, heat water and 1-MCP + heat water treatment during postharvest storage period. However MiNHL1 gene was upregulated by salt, PEG and heavy metal treatment, and downregulated by low temperature treatment. Our results reveal that the MiNHL1 gene may play an important role on fruit postharvestregulation and stress response in mango.