Heat shock protein hsp70 cognate gene expression in vegetative and reproductive organs of Lycopersicon esculentum.

We have detected hsc70 gene expression (heat shock protein hsp70 cognate) during vegetative growth and reproductive development in tomato (Lycopersicon esculentum). Using RNA from a tomato hsc70 cDNA as a probe in in situ hybridizations, we have determined expression patterns of hsc70 in nonstressed tomato roots, stems, leaves, flowers, and developing fruits. We have localized high levels of hsc70 transcript to the vascular system of the ovary, dividing cells of the lateral root tips, and the inner integument of developing seeds. We also see expression in the transmitting tissue, in immature anthers, and in embryos. We cannot detect expression in mature pollen, xylem, or ovules. These data indicate that the expression of at least some tomato hsp70 family members is developmentally regulated.