Isolation and characterisation of Asparagus officinalis L. cDNA clones encoding two forms of ubiquitin mRNA

摘要

Abstract A cDNA library constructed from the immature, rapidly developing tip region of spears of Asparagus officinalis plants was screened by hybridisation with a cDNA clone for a polyubiquitin mRNA from Antirrhinum majus. Two independent, positively hybridising cDNAs were obtained, and their nucleotide sequence determined. One clone (pTIP22) encodes a partial cDNA for a ubiquitin‐ribosomal fusion mRNA and the other (pTIP24) a partial cDNA for a polyubiquitin mRNA. The abundance of transcripts corresponding to pTIP24 was relatively constant in a range of intact tissues but decreased following spear harvest. Investigations of mRNA abundance during spear development demonstrated that the changes detected were harvest‐induced. Transcripts corresponding to pTIP22 were associated with regions of active cell development, and decreased in abundance following spear harvest.