| Tomato belongs to solanaceae Lycopersicon plants and is a kind of Self-pollinating crop. It is the nutrient-rich fruits which contains much carotene, lycopene, vitamin C and citric acid and inorganic salts. In addition, because of easy conversion,large fruit,more seeds , it is a very important model plant in plant tissue culture,genetic engineering and other studies.In the production, tomato are mainly of hybrid species, which have obvious heterosis, hybrid tidy high, strong resistance. But so far, we get the hybrid species often by artificial emasculation, thus the selection of male sterility line is particularly urgent and important. T431 is a functional style male sterility line of long-stigma tomato by the selection through many generations. It can reach 95% of the infertility rate in the field of more than 20℃temperature, but at low temperature conditions (day/night as 18℃/10℃) the style recessed or flush with the anthers from sterile material into the fertile material. The lab has previously constructed T431 positive and negative temperature sensitivity to the subtraction library, in this study, we take the transcriptional coactivator MBF1 (Multiprotein Bridging Factor 1, multiprotein bridge factor) for the objection, cloning full-length and preliminary expression analysis of its role in T431 style development, for illuminating regulatory mechanism of the phenomenon of T431 long-stigma temperature sensitive to provide reference ultimately.1. In this study, 725 subtractive clones were screened by PCR method from positive and negative library of tomato T431. We found that 429 clones have different expression, the sequencing analysis of differentially expressed genes obtained 374 ESTs available sequence, which availability to 87.2%.2. The results of a comparative analysis of the obtained sequences to Genebank showed that 374 ESTs sequences available, and of 324 with the protein coding function, and the remaining 50 ESTs with homology with known proteins or can not find any homologous sequence. Among the 324 ESTs with protein sequences, there are 228 known functional sequences, and other 96 sequences are speculation, assumptions, or proteins of unknown function with high homology.3. By BLASTx and BLASTn, we categorizate the sequences of all ESTs in functional classification. It was found involved in primary metabolism (16%), energy metabolism (9%), disease resistance and defense (12%), signal transduction (of 11%) genes than other processes more than a small number of genes involved in protein synthesis and processing plants, material transport, transcription regulation, cell structure and growth and development process.4. We choose the ESTs which are related to transcription regulation of eukaryotic translation initiation factor (eIF-5A),pectin methyl-esterase (Pme),transcriptional coactivator MBF1, and with semi-quantitative RT-PCR for expression analysis showed that at room temperature and low temperature conditions, we found that the two genes are not related to the T431's stigma development under low temperature stress. The MBF1 gene at room temperature in the T431 roots, stem apexes, and leaves were expressed, but expression of the stem apexes is low; the flower bud differentiation of the T431 after the low temperature 3d, 6d, 9d, the expression in the root keep consistent; The expression in leaves at a slightly increase in the initial low temperature, and then decreased; while the stem apexes of low temperature treatment in 3d, its expression was significantly increased, with the low temperature treatment was gradually reduced, which manifested that MBF1 may be involved in floral organ morphogenesis, and inhibit the T431 stigma elongation.5. Obtained a transcription coactivator gene encoding the full length cDNA sequence MBF1, which named LeMBF1. This gene contains a 420bp open reading frame encoding 140 amino acids. With The NCBI's BLASTx and DNAMAN software, after amino acids of LeMBF1 and MBF1 protein of other plants were compared, we found that its amino acid sequence similarity with the potato StMBF1 the highest, reaching 97%.6. From T431 genome, we got the full-length DNA sequence of MBF1. With the DNA sequences of LeMBF1 were compared with the mRNA sequences are completely similar, we considered that the gene does not contain introns.
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