When tested for ornithine and arginine decarboxylases, pyrrolizidine alkaloid-bearing Senecio riddellii, S. longilobus (Compositae), and Crotalaria retusa (Leguminosae) plants exhibited only ornithine decarboxylase activity. This contrasts with previous studies of four species of pyrrolizidine alkaloid-bearing Heliotropium (Boraginaceae) in which arginine decarboxylase activity was very high re...

Resveratrol has been identified as a wine component related to moderate wine consumption and a reduction in serum cholesterol levels. Processes such as wine fining that result in loss of resveratrol during winemaking are therefore of interest, and led to these present studies. A number of agents were compared and were found to lower resveratrol levels in all wines to some extent. Results from t...

Antimicrobial peptides are an abundant group of proteinaceous compounds widely produced in the plant kingdom. Here, we report the purification and partial characterization of a novel antimicrobial peptide compound from horseradish tissue culture (Armoracia rusticana), named Ar-AMP, with bactericidal activity against both Gram-positive and Gram-negative bacteria. The production of antimicrobial ...

Evidence is presented for the operation in nodules of at least four systems for restoring functional ferrous leghemoglobin (Lb2+) from its inactive, ferric form. (i) Reduction offerric leghemoglobin (Lb3+) by a reductase. The enzyme is a flavoprotein of 100 kDa with two equally sized subunits and exhibits a K. of 9 ,uM for soybean Lb3+ component a and a K. of 51 ,IM for NADH. NADPH is only 30% ...

Most vascular plants harbour mutualistic fungi in their roots, forming associations called mycorrhizas (Brundrett & Tedersoo, 2018; Van Der Heijden et al., 2015). Mycorrhizas are chimeric organs, composed of both plant tissues and fungal hyphae, where nutrient exchanges can occur directions (Smith Read, 2008). While provide photosynthetic acquired carbon to partners, the latter improve hydro-mi...

Pawpaw (Asimina triloba) fruit stored longer than 4 weeks at 4 8C fail to ripen normally and may develop internal discoloration, indicative of chilling injury (CI). To determine if loss of antioxidant protection in the fruit tissue during cold storage could be the cause of these problems, the levels of total, reduced, and oxidized glutathione and ascorbate and the key enzymes glutathione reduct...

Resveratrol is one of the wine components related to moderate wine consumption and reduction of serum cholesterol levels. The standard addition method was used with a high pressure liquid chromatography procedure to calculate resveratrol levels. Grape variety, UV light exposure, enzyme addition, skin contact time, and the fining agents, carbon and PVPP, affected the resveratrol levels of wines ...

words 250; characters 1777) Sucrose synthase (SUS) cleaves sucrose to form UDP-glucose and fructose, and exists in soluble (s-SUS) and membrane-associated (m-SUS) forms, with the latter proposed to channel UDP-glucose to the cellulose synthase complex on the plasma membrane of plant cells during synthesis of cellulose. However, the structural features responsible for membrane localization and t...