PROTEIN CHANGES IN ENDODORMANT SHOOTS, SPURS, AND FLORAL BUDS OF VARIOUS FRUIT CROPS DURING WINTER

Abstract

We have previously demonstrated that a protein of ∼62 kD decreases in response to temperature during the final stages of chilling unit accumulation in dormant peach flower buds (Lang and Tao, 1991, HortSci. 26:733). To further examine proteins that potentially may be associated with endodormancy, floral buds, spurs, and/or shoots were collected during winter from `Anna' apple, various blueberry cultivars, `MidSouth' grape, `20th Century' pear, `Hawthorne' peach, and `Santa Rosa' plum. Soluble proteins were extracted and analyzed by one-dimensional SDS-PAGE. A major protein of ∼62 kD was present in plum, and lesser amounts of one or two similar proteins were found in blueberry, but not in apple or grape. The 62 kD peach protein originally found in buds was also present, in lesser proportions, in peach shoot xylem and phloem tissues, but not in petioles or seeds. Apple exhibited a major protein band at ca. 31 kD that may be a storage protein. The similarities and disparities in protein profiles between fruit crops, as well as changes that occur during winter, will be discussed with respect to dormancy, cold hardiness, and storage compounds.