A gene for pectate lyase expressed in elongating and differentiating tissues of a Japanese willow (Salix gilgiana)

A cDNA clone (pSgPEL1) for pectate lyase (PEL) was isolated from a cDNA library of the dioecious willow Salix gilgiana Seemen. The predicted amino acid sequence of the encoded protein, SgPEL1, resembled those of nonpollen PELs more than those of pollen-specific PELs. Constitutive expression of the SgPEL1 gene was detected in all organs examined, although the transcript was most abundant in stems and male catkins. The expression of SgPEL1 was developmentally regulated in leaves and stems, with the highest levels of expression in young leaves and stems. Analysis by in situ hybridization of reproductive organs revealed that expression of SgPEL1 was restricted to the elongating filaments of stamens, the secretory tissues of pistils and the xylem parenchyma cells of catkins. These results suggest that SgPEL1 encodes a PEL that is localized in nonpollen tissues and that SgPEL1 functions in elongating and differentiating tissues.