Abstract: A gene coding for Pin m III, which is associated with overwintering and frost hardiness in western white pine, has been cloned and characterized. The gene contains an open reading frame of 486 base pairs, encoding a protein of 161 amino acid residues, with a calculated molecular weight of 18002.30 daltons. The predicted isoelectricl point is 5.534. The gene is transcriptionally regulated with the highest expression in fall and winter months. The protein Pin m III is high in infected tissue such as canker. Accordingly, the gene can be used to determine frost hardiness and blister resist fungus susceptibility in conifers.

Abstract: A method of determining frost hardiness of a conifer seedling, which comprises detecting an amount of a cold protein in tissue of said conifer, the cold protein being a protein of approximately 19 kD that increase significantly in amount in the conifer during fall season (autumnal) months and that imparts frost hardiness to the seedling, and then assessing frost hardiness based on said detected amount. In the case of Pinus lambertiana, the cold protein includes the N-terminal sequence: Val--Ser--Gly--Thr--Ser--Ser--Thr--Glu--Glu--Val--Val--Gln--Asn--Glu--Ala- -Arg--Arg--Leu--Trp--Asn ?SEQ ID NO:1!; and in the case of Pinus monticola, the cold protein includes the N-terminal sequence: Val--Ser--Gly--Thr--Ser--Ser--Thr--Glu--Glu--Val--Val--Gln--Val--Glu--Ala- -Arg--Arg--Leu--Trp--Asn--Ala--Thr--Thr--Lys--Asp ?SEQ ID NO:3!. The invention also relates to conjugates and antibodies used in the method.

Abstract: White pine blister rust, which infects five-needle pines such as eastern white pine, western white pine and sugar pine, is caused by the fungus Cronartium ribicola. This invention provides monoclonal antibodies which recognize antigens of basidiospores of the fungus. The antifungal antibodies can be genetiacally incorporated into white pines to generate blister resistant trees.