Isolation, assay, biosynthesis, metabolism, uptake and translocation, and function of proline in plant cells and tissues

Abstract

The amino acid L-proline has been the subject of intensive research during the past ten to fifteen years. This stems from the observations that it incorporates into peptide linkage thereby serving as a precursor to peptidyl-bound L-hydroxyproline, a constituent of “extensin,” and that it accumulates when some plants are exposed to diverse biological and environmental stresses. The contents of selected papers which have been published during the last quarter of a century regarding the isolation, assay, biosynthesis, metabolism, transport and function of L-proline within various plant tissues and their cells are both interpreted and summarized in this review. Occasionally, relevant information from animal and bacterial systems concerning these topics is included. Hydroxyproline-containing proteins are not considered.