Proline metabolism in plants under environmental stresses. Progress report, April 1, 1982-December 31, 1982

Technical Report · Wed Dec 01 04:00:00 EST 1982

OSTI ID:6856859

Stewart, C R; Elthon, T E

This report summarizes progress toward understanding the basic mechanisms involved in proline accumulation by plants under environmental stresses. This accumulation is thought to be part of the process of osmoregulation - an adaptive phenomenon that occurs in plants and other organisms to aid survival in arid and saline environments. This understanding will aid in developing cultural strategies for producing food and biomass in marginal lands and environments. We have shown that proline transport into the mitochondrial matrix is protonmotive, thus energy dependent but not driven by an electrical gradient. Transport rates exceed oxidation rates under non-phosphorylating conditions. We have been able to study the nature of specific inhibition of proline oxidation using an artificial inhibitor, thiazolidine-4-carboxylate. This compound mimics the effects of stress on proline oxidation. Attempts have been made to obtain cell-free proline synthesis in pursuit of the enzyme, gamma-glutamokinase which is probably the enzyme most affected by stress. We have not been successful using conventional enzyme extraction procedures. We will continue this work using isolated cells and perhaps protoplasts. We have determined the metabolic mechanism which causes proline to accumulate in salt stressed leaves. The results are qualitatively similar to those obtained in drought- and ABA-induced leaves with minor quantitative differences. A preliminary draft of a manuscript is included.

• Research Organization: Iowa State Univ. of Science and Technology, Ames (USA). Dept. of Botany
• DOE Contract Number: AC02-82ER12028
• OSTI ID: 6856859
• Report Number(s): DOE/ER/12028-1; ON: DE83002735
• Country of Publication: United States
• Language: English

Related Subjects

550500* -- Metabolism
59 BASIC BIOLOGICAL SCIENCES
AMINES
AMINO ACIDS
AZOLES
BIOLOGICAL STRESS
BIOSYNTHESIS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
METABOLISM
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDATION
PLANTS
PROLINE
PYRROLES
PYRROLIDINES
SYNTHESIS