Complementary DNA amplified fragment length polymorphism (cDNA-AFLP) analysis was conducted to analyze differential expression of Ht2-related genes between maize (Zea mays) near-isogenic lines (NILs), Huangzaosi (HZS) and HuangzaosiHt2 (HZSHt2), following treatment with a crude extract of the HT-toxin. Twenty-one transcript-derived fragments (TDFs), designated H1 to H21, were specifically expressed or upregulated in HZSHt2 following exposure to the HT-toxin. Among them, 4, 7, 4, 2, 2 and 2 TDFs were detected at 3, 6, 12, 24, 48 and 72 h after treatment, respectively. BLAST analysis showed that H1, H11, H13 and H15 are related to regulation of the defence response to environmental stresses. H3, H6 and H10 are associated with energy metabolism. H5, H17 and H18 are involved in photosynthesis. H9 is similar to ubiquitin-like domain containing CTD phosphatase. H8, H9, H16 and H20 are probably transcription factors. The genes associated with basal energy metabolism and signal of stress tolerance were mainly expressed at 3 h after treatment. Transcription factor and most genes for stress tolerance were expressed at 6 h after treatment. RT-PCR analysis demonstrated that H8 was upregulated in HZSHt2 only at 6 h after exposure to the HT-toxin and H13 was upregulated at 6 and 12 h. The full length cDNAs of H8 (GenBank accession number FJ600319) and H13 (FJ600320) were cloned. The deduced protein encoded by H8 cDNA showed 77% homology to the Plus-3 domain containing protein, which is found in yeast gene Rtf1. H13 cDNA encodes a QM-like protein, which is an important protein in plant tolerance to environmental stress. The mechanism regulating the resistance of Ht2 to the HT-toxin might involve a translation elongation factor or an upregulated QM-like protein.
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Document Type: Research Article
The National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI)/Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
Publication date: 01 January 2010