Cucumber_fruit_growth
Cucumis sativus Transcriptome or Gene expression
Fruit development proceeds from cell division to expansion,  maturation, and ripening. Expansion is critical for size, yield, and  quality; however, this period of development has received little  attention. We used 454- pyrosequencing to develop a cucumber (Cucumis  sativus) fruit transcriptome, identify highly expressed transcripts,  and characterize key functions during exponential fruit growth. The  resulting 187,406 expressed sequence tags (ESTs) were assembled into  13,878 contigs. Quantitative real-time polymerase chain reaction  (qRT-PCR) verification of differentially expressed genes from fruit of  different ages, and high correlation in transcript frequency between  replicates, indicated that number of reads/contig reflects transcript  abundance. Putative homologs were identified in Arabidopsis thaliana  for 89% of the contigs represented by at least 10 ESTs; another 4% had  homologs in other species. The remainder had homologs only in cucurbit  species. The most highly expressed contigs were strongly enriched for  growth (aquaporins, vacuolar ATPase, phloem proteins, tubulins,  actins, cell wall-associated, and hormone-related), lipid, latex, and  defense-related homologs. These results provide a resource for gene  expression analysis in cucumber, profile gene expression in rapidly  growing fruit, and shed insight into an important, but poorly  characterized, developmental stage influencing fruit yield and  quality.