The in vivo oxidation of the C(4) and C(5) of 5-aminolevulinic acid (ALA) to CO(2) has been studied in etiolated barley (Hordeum vulgare L. var. Larker) leaves in darkness. The rate of (14)CO(2) evolution from leaves fed [4-(14)C]ALA is strongly inhibited by aminooxyacetate, anaerobiosis, and malonate. The rate of (14)CO(2) evolution from leaves fed [5-(14)C]ALA is also inhibited by these treat...

The protoheme content of etiolated, greening, and fully greened bean (Phaseolus vulgaris L. var. Light Red Kidney) leaves has been studied. The protoheme level in etiolated and fully greened leaf tissue stays relatively constant from age 7 to 14 days. In agreement with the studies reported for barley (Castelfranco and Jones 1975 Plant Physiol 55: 485-490), the protoheme content of greening bean...

Levulinic acid (LA), a competitive inhibitor of delta-aminolevulinic acid (ALA) dehydratase (EC 4.2.1.24), has been used extensively in the study of ALA formation during greening. When [1-(14)C]LA is administered to etiolated barley (Hordeum vulgare L. var. Larker) shoots in darkness, (14)CO(2) is evolved. This process is accelerated when such tissues are incubated with 2 millimolar ALA or plac...

16 isolates of fusarium culmorum obtained from washington, north dakota and minnesota were tested for pathogenicity on five cultivars and lines: chevron, ci 9549, excel, karl, larker, morex, robust, m48, m66 and m69 were evaluated for reaction to the mixture of all isolates of the pathogen under field condition. the results of glasshouse test indicated that the isolates 10, 25 and 27 were the m...

Leaves from dark-grown barley (Hordeum vulgare L. var Larker) seedlings grown in the presence and absence of fluridone were used to determine whether or not abscisic acid (ABA) accumulation was necessary for proline to accumulate in wilted tissue. Wilted tissue (polyethylene glycol-treated) leaves from fluridone-grown seedlings did not accumulate ABA but did accumulate proline at a rate that wa...

Application of levulinic acid (LA), a competitive inhibitor of delta-aminolevulinic acid (ALA) dehydratase, to greening plant tissues causes ALA to accumulate at the expense of chlorophyll. 4,6-Dioxoheptanoic acid (DA), which has been reported to be an effective inhibitor of this enzyme in animal systems, has a similar but more powerful effect on ALA and chlorophyll metabolism in greening leave...

Excised barley (Hordeum vulgare var Larker) leaves were treated with salt solutions or wilted. After the treatment period, the leaves were allowed to recover in a 50 millimolar sucrose and 1 millimolar glutamate solution, and proline, Na(+), and K(+) were measured at intervals. Na(+) and K(+) concentrations stayed at a constant high level after the salt treatments, and proline increased to a st...

Proline accumulation in NaCl-treated excised barley (Hordeum vulgare var Larker) leaves was studied. Leaves were treated by placing the cut end in NaCl solutions and allowing the salt to enter the leaf via the transpiration stream. Leaves treated this way maintained turgor while the sodium content increased and the osmotic potential decreased. Proline began accumulating after 12 hours and conti...