Proteins immunologically related to a 310-kD stress protein in four grass species

A search for proteins immunologically related to the 310-kD cold-shock prot ein from winter rye was undertaken in several grass species differing in to lerance to low temperatures: maize (Zea mays L.), winter wheat (Triticum ae stivum L.), winter rye (Secale cereale L.), and a highly resistant wild spe cies lyme-grass (Elymus sibiricus L.). Western-blot analysis of proteins se parated by native PAGE demonstrated that all tested plants, when grown at 2 6 degrees C, contained common proteins with mol wts of 230 and about 140 kD that were immunologically related to 310-kD protein. Considerable amounts of proteins with mol wts of 310 and 480 kD were present only in winter rye plants. Lyme-grass contained several specific proteins with mol wts of 320- 380 kD immunologically related to 310-kD protein. SDS-PAGE showed that all these proteins cross-reacting with antibodies against 310-kD protein consis ted of different combinations of the two types of subunits.