Detection of Norspermidine and Norspermine in Medicago sativa L. (Alfalfa)

Abstract

Shoot meristem tissues of alfalfa, Medicago sativa L., were found by high performance liquid chromatography analyses to contain the uncommon polyamines, norspermidine and norspermine. The chemical structures of norspermidine and norspermine, purified from alfalfa, were confirmed by comparison of mass spectra with those from authentic standards. The discovery of norspermidine and norspermine in alfalfa implicates the presence of at least two biosynthetic enzymes, a polyamine oxidase and a previously uncharacterized aminopropyltransferase.Much research has implicated the naturally occurring diamine, putrescine,2 and the polyamines, spermidine and spermine, in processes controlling cellular growth in prokaryotes, higher animals, and plants. They are involved in numerous aspects of plant growth, developmental processes, and in the response of plants to specific abiotic stress stimuli especially at the level of the membrane (1,(20)(21)(22). In microbial systems, polyamines have been shown to modulate membrane fusion, exhibit differential preferences for alignment of membrane phospholipids, and mediate preferential attachment or expulsion of membrane surface proteins (15). These and other observations have important implications for protection by polyamines of the structural integrity and function of both prokaryotic and eukaryotic organisms susceptible to osmotic shock (14).Relatively little is known about the occurrence of other structurally related and uncommon polyamines such as norspermidine, norspermine, or the higher mol wt pentamines and hexamine. These uncommon polyamines were initially discovered in some thermophilic (6,16) lichens, certain fungi (10), and eukaryotic algae (9), but not in Pteridophyta or in higher plants (10).The investigation of the distribution of the uncommon polyamines in biological systems is far from complete. Thus, during a study in our laboratory of the changing patterns of polyamine titers among related populations of drought tolerant and drought susceptible alfalfa in response to imposed stress conditions (17, 18), attention was given to the identification of new polyamines apart from the more common putrescine, spermidine and spermine. In this communication, we report analytical and structural evidence for the occurrence of norspermidine and norspermine in alfalfa.

Putrescine Aminopropyltransferase Is Responsible for Biosynthesis of Spermidine, Spermine, and Multiple Uncommon Polyamines in Osmotic Stress-Tolerant Alfalfa

“…However, PAPT does not explain the accumulation of the trimethylenic uncommon polyamines such as norspermidine, norspermine, and caldopentamine (Rodriguez-Garay et al, 1989;Kuehn et al, 1990b). The trimethylenic polyamines are most likely to be biosynthesized from DAP (Fig.…”

“…Reaction products were separated by paper electrophoresis, and radiolabeled conversions from the I'4Clputrescine substrate into the reaction products were quantified by liquid scintillation spectrometry. Mature plant tissue samples were comprised of a composite of immature reproductive and meristematic shoot tip tissues collected from plants grown in a rainout shelter and water-deficit-stressed as described by Rodriguez-Garay et al (1989) and Kuehn et al (1990a) Figure 3. TLC separation of polyamine products of alfalfa PART activity.…”

“…HPLC separations of dansylated polyamines were performed as described by Rodriguez-Garay et al (1989). Enzyme reaction products from alfalfa extracts, which were first separated by paper electrophoresis, were eluted from the paper strips using 6 N HCl and then prepared for HPLC analysis.…”

Polyamines in Eukaryotes, Bacteria, and Archaea

“…Nspd is also present in the green alga phylum Chlorophyta, where it is prevalent in classes Trebouxiophyceae, Chlorophyceae, including Chlamydomonas and Volvox, and Ulvophyceae but absent in Prasinophyceae (43). Mosses and the flowering plant alfalfa were also found to contain Nspd and Nspm (44,45). Little is known about the biosynthesis of Nspd and Nspm in eukaryotes, and there is no equivalent of the Nspd biosynthetic pathway found in the ␥-proteobacterium Vibrio cholerae.…”

Significance of UV-C Hormesis and Its Relation to Some Phytochemicals in Ripening and Senescence Process

“…Putrescine is the precursor for the synthesis of spermidine and spermine (Nambeesan et al, 2008). Apart from the three well known free forms of polyamines, there are some lesser known and studied polyamines such as 1,3-diaminopropane and homospermidine which have been detected in plants (Rodriguez-Garay et al, 1989), algae (Hamana & Matsuzuki, 1982), bacteria (Tait, 1985) and animals (Pandey et al, 2000).…”