A developmentally regulated early-embryogenesis protein in pea (Pisum sativum L.) is related to the heat-shock protein (HSP70) gene family.

A cDNA clone, pCD7, was shown to hybrid-select from developing seeds of Pisum sativum L. an mRNA that translated into a polypeptide of apparent Mr 90 000. The translation product was observed only in the earliest stages of embryogenesis and was detected at a developmental stage when virtually all the cotyledon cells are mitotic. Sequence analysis of pCD7 showed it to correspond to a member of the 70 000-Mr heat-shock protein (HSP70) gene family. Transcripts corresponding to pCD7 were detected in different P. sativum organs, with roots apparently showing lower levels of pCD7-homologous RNA than other organs. Hybridizations to P. sativum DNA identified polymorphisms in the genomic DNA corresponding to pCD7 and the segregation of these in selected crosses indicated the existence of at least two genetic loci, one of which mapped to an existing linkage group.