Differential expression of heat-shock proteins Hsp70 and Hsp90 in vegetative and reproductive tissues of Iris pumila

Tissue-specific variation in Hsp70 and Hsp90 expression was studied in vegetative (leaf) and reproductive organs (floral tube, ovary and stamen) of Iris pumila plants originating from a sun-exposed and a shaded natural population, which experienced similar growth conditions in an experimental garden. Western blot analysis revealed the presence of both the Hsps in all examined tissues, but at different amounts. In addition to Hsp90a and Hsp90b that were previously detected in vegetative tissues, three new immunospecific bands, designated herein as Hsp90c, Hsp90d and Hsp90e, were recognized with the same anti-Hsp90 antibody in the reproductive tissues. Apart from showing tissue-specific differences in the relative amount of Hsp70 and Hsp90, our study provides evidence that the degree of Hsps expression within the same tissue also depended on the habitat type that the I. pumila plants were derived from.