TDF1(transcription-drived fragment) was homologous to the predicted S. lycopersicum nonspecific lipid-transfer protein,nsLTP 2-like(91%), and it was significantly upregulated in response to C. fulvum(cladosporium fulvum) infection in tomato plants.In this experiment, the full-length cDNA of nsLTP 2-like was cloned using RACE technology based on the sequence of TDF1(GenBank: JZ717725). A full-length, 625 bp(GenBank: KU366289), cDNA sequence, which with 98% similarity to nsLTP 2-like gene(GenBank: XM015233692) was obtained. This cDNA contains an ORF(open reading frame) with full-length of 345 bp, coding of 114 amino acids, including 12.3% Ala and Gly. Protein molecular weight was 11.51 ku, the isoelectric point(pI) was 8.99, and average overall hydrophilicity was 0.412, with one phosphorylation sites, belonging to volatile acidic nuclear protein. Secondary structure prediction showed that α-Helix accounts for 30.7%, extension chain for 12.28%, β-corner for 9.65%, and random coil for 47.37%. Through comparative analysis of the homology among species, it was found that the amino acid sequence of tomato nsLTP 2-like protein had a high similarity with other plants, and with a specific conserved sequence which might related features in nsLTP 2-like protein. It also be analyzed the gene expression pattern of tomato in different parts and under different stress conditions.The results showed that nsLTP 2-like gene was up-regulated in varying degrees, under the condition of cold stress, exogenous hormone spraying and cladosporium fulvum infection. Therefore, it was speculated that the gene played a role in response to abiotic and biotic stress in tomato.
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