Biosynthesis, 2H-NMR, Phytoalexin, Pisatin, Pterocarpan 2H-NMR analysis of the 6a-hydroxypterocarpan phytoalexin pisatin derived in CuCl2-treated pea [Pisum sativum) pods from [6,1 la -2H2]maackiain has demonstrated the retention of all 2H labels. This establishes that no pterocarp-6a-ene or pterocarp-6-ene interm ediate is involved, and thus confirms a direct 6a-hydroxylation mechanism for the...

Dose response curves were determined for phytochrome phototransformation and for a phytochrome-controlled decrease in geotropic curvature in epicotyls of dark-grown Pisum sativum L. cv. Alaska. Ten times as much light was required to produce a spectrophotometrically detectable transformation of phytochrome as was required to produce a significant change in the geotropic response. The red light ...

Carbamoyl phosphate synthetase activity was measured in partially purified extracts from cotyledons of developing and germinating seeds of Pisum sativum L. Some properties of the enzyme were established. During cotyledon development, the activity initially increased sharply but decreased during further development. The activity from germinating seeds was only one-tenth of the maximum activity a...

A procedure has been developed for the purification of amine oxidase (E.C. 1.4.3.4) from etiolated pea epicotyls (Pisum sativum cv. Little Marvel). The enzyme is sensitive to copper chelating reagents and carbonyl reagents, but is not inhibited by sulfhydryl reagents. The purified enzyme has a molecular weight of 1.85 x 10(5), as determined by sedimentation equilibrium centrifugation, and has b...

We observed no exchange between deuterated ethylene (C(2)D(4)) and the hydrogen of pea seedlings (Pisum sativum L. cv. Alaska). This suggests that bonding forces in which exchange could readily occur are not important in the physiological action of ethylene. Deuterated ethylene was just as effective as normal ethylene in inhibiting the growth of pea root sections. These results indicate that sp...

Purified pea (Pisum sativum) cotyledon F1-ATPase contains six subunits rather than the five usually reported for F1-ATPases. The additional 26.5 kDa (delta) subunit is shown by immunoblotting and N-terminal amino acid sequencing to be similar to bovine oligomycin-sensitivity-conferring protein (OSCP). It is concluded that the delta subunit of plant mitochondrial F1-ATPase is the plant OSCP. Thi...

Choline acetyltransferase was demonstrated in nettles (Urtica dioica), peas (Pisum sativum), spinach (Spinacia oleracea), sunflower (Helianthus annuus) and blue--green algae by using a Sepharose--CoASH affinity column. The column effected a 1500-fold purification of the enzyme from nettle homogenates and was required for demonstrating activity in the other higher plants. Demonstration of the en...

Protoplasts isolated from young and mature pea leaves (Pisum sativum L.) were broken and their contents fractionated by differential centrifugation or on sucrose-density gradients. Asparaginase was found only in the cytosol of young leaves. Asparagine aminotransferase was found in both young and mature leaves and was localized exclusively in the peroxisome. This corroborates the observation tha...

Levels of asparaginase activity from developing pea leaves (Pisum sativum) were found to change on a daily basis, increasing during the light period and decreasing in the dark. During extended periods of light, high levels of activity were maintained, while prolonged dark reduced activity to a low value. Half-expanded leaves exhibited the greatest change in activity over the photoperiod. Very y...