Analysis of expressed sequence tags from Petunia flowers

Petunia cDNA libraries were prepared from whole flower parts (including buds), pollen, and pollen tubes to generate expressed sequence tags (ESTs). A total of 7001 random clones were subjected to unidirectional sequencing, resulting in identification of 611 groups of related sequences and 2410 singletons. Highly conserved 1098 ESTs were functionally assigned. ESTs encoding proteins involved in the calcium-dependent signal pathway and in cell wall metabolism such as pectin degradation and modification were frequently found in the pollen and pollen tube libraries. The 2976 cDNA clones from the bud/flower cDNA libraries were used for the construction of microarrays. The 112 functionally annotated genes were up-regulated in the buds just before opening, including the genes for anthocyanin pigmentation and protein degradation. These ESTs and microarrays will serve the analysis of floral traits of petunias.