ISOLATION AND CHARACTERIZATION OF POLLEN-SPECIFIC MAIZE GENES WITH SEQUENCE HOMOLOGY TO RAGWEED ALLERGENS AND PECTATE LYASES

A cDNA clone (Zm58.1) was isolated by differential screening from a cD NA library made to mature Zea mays pollen, and shown to be pollen-spec ific by RNA blot analysis. When this partial-length clone was used to probe a genomic library, a similar but distinct pollen-specific genomi c clone (68% sequence identity) was isolated (Zm58.2). The putative pr oteins coded for by these two clones show sequence homology to several flower-expressed gene products from various plant species, including known pollen allergens from short ragweed (Ambrosia artemisiifolia), a nd to pectate lyases from the plant pathogenic bacteria Erwinia spp. T he two genes map to different chromosomes.