Tree identification by fruit seeds.
Fruit seeds are an important trait that make substantial contributions to yield of many crops and may play a critical role in fruit marketability. In this study, we sequenced the complete transcriptome of pear fruit using the Roche/454 technology and found that the pear has 26,363 unigenes. Of these, 2882 unigenes were annotated based on non-redundant database and 2104 were found to encode for fruit-specific proteins. Furthermore, 234 unigenes encode for major cell wall structural proteins. Based on GO classification, we identified a total of 9722 unigenes corresponding to 1608 GO terms that were then classified into three major categories: biological process, cellular component, and molecular function. Of these, 441 unigenes were related to biotic and abiotic stress response in the pear. Finally, 1193 differentially expressed genes were identified by using quantitative real-time PCR (qRT-PCR). Correlation analysis revealed that the qRT-PCR results were in good agreement with the 454-transcriptome data. The pear transcriptome dataset can provide important resources for genetic studies in pears, and could be used as a reference for other fruit species. In addition, this dataset provides insights into the regulatory mechanism of fruit yield-related traits during pear fruit development.