William V. Dashek

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

AbstractThe 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.L-proline was reported to be a constituent of leaves as early as the 1950’s. Since then, it and its analogues have been extracted from the organs of a variety of plants. The analogues include: methyl-hydroxylproline; 4-methylene-DL-proline; L-azetidine-2-carboxylic acid; 2,3,cis-3,4-trans-dihydroxy-L-proline; L-pipecolic acid and 4-trans-hydroxypro-line. L-proline can be both detected and quantified by colorimetric, combined fluorometric-amino acid analyzer and gas Chromatographic procedures. L-proline may be synthesized from L-glutamic acid via the following biosynthetic pathway: L-glutamic acid

Aflatoxin B1 influence on excised soya-bean root growth, 14C-leucine uptake and incorporation

\underrightarrow {\gamma - glutamic acid kinase}

Aflatoxin formation on whole and ground cumin and anise seeds

γ-glutamyl phosphate

Thin layer chromatographic analysis of possible aflatoxins within grain dusts

\underrightarrow {\gamma - glutamyl phosphate reductase}

Methods for the Ultrastructural Analysis of Plant Cells and Tissues

γ-glutamyl semialdehyde