Marshall Keyster

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The response of two maize (Zea mays L.) genotypes, named GR (salt-tolerant) and SK (salt-sensitive), to salt stress (150 mM NaCl) was investigated under controlled environmental growth conditions. Genotype SK experienced more oxidative damage than the GR genotype when subjected to salt stress, which corresponded to higher O2 − production rate and H2O2(More)
Ascorbate peroxidase is one of the major enzymes regulating the levels of H2O2 in plants and plays a crucial role in maintaining root nodule redox status. We used fully developed and mature nitrogen fixing root nodules from soybean plants to analyze the effect of exogenously applied nitric oxide, generated from the nitric oxide donor(More)
Salinity stress causes ionic stress (mainly from high Na⁺ and Cl⁻ levels) and osmotic stress (as a result of inhibition of water uptake by roots and amplified water loss from plant tissue), resulting in cell death and inhibition of growth and ultimately adversely reducing crop productivity. In this report, changes in root nitric oxide content, shoot and(More)
It was assumed that salt-induced redox changes affect amino acid metabolism in maize (Zea mays L.), and this influence may be modified by NO. The applied NaCl treatment reduced the fresh weight of shoots and roots. This decrease was smaller after the combined application of NaCl and an NO-donor(More)
Nitric oxide is a small gaseous signaling molecule which functions in the regulation of plant development and responses to biotic and abiotic stresses. Recently, we have shown that nitric oxide is required for development of functional nodules. Here, we show that inhibition of nitric oxide synthase enzymatic activity (using N(ω)-nitro-L-arginine) reduces(More)
Caffeic acid (3,4-dihydroxycinnamic acid; CA) is a cinnamic acid occurring naturally in a variety of plant species. In this study, the effects of caffeic acid (100 μM caffeic acid) on soybean root nodule superoxide content, cell viability and superoxide dismutase (SOD; EC 1.15.1.1) activity were evaluated in the presence and absence of salinity stress(More)
Brassica napus L. (cv. AV Garnet) seeds were pre-treated with 15μM 3,3'-diindolylmethane (DIM) to investigate whether DIM could enhance seed germination. Further treatment of seedlings with 15μM DIM for 14days explored the effects on seedling shoot growth. Exogenous DIM led to improved germination percentage, increased seedling shoot lengths, and increased(More)
The effects of a nitric oxide synthase inhibitor (N(ω)-nitro-L-arginine) on soybean growth parameters and nodule functioning were investigated, along with soybean nodule cell viability and cysteine endopeptidase activity. N(ω)-nitro-L-arginine reduced soybean growth parameters, inhibited nodule nitrogenase activity, and caused a decrease in nodule cell(More)
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