Desaturation of Oleic and Linoleic Acids by Leaves of Dark- and Light-grown Maize Seedlings 1

AUTOR(ES)

Hawke, John C.

RESUMO

Oleate and linoleate desaturation in leaves of maize seedlings was largely independent of previous light treatment of the seedlings; there was no evidence of light-induced desaturase activities. These results are in sharp contrast to those observed with developing cucumber cotyledons in which pronounced increase in desaturation occurs after exposure of tissue to light. The rates of desaturation of oleate were about four times those of linoleate in both etiolated and 16-hour greened maize leaves. In both etiolated and greened tissues, about two-thirds of the label from oleate was esterified after 4 hours, half of which was in phosphatidylcholine. Phosphatidylcholine and diglyceride contained large proportions of [14C]linoleate formed from [14C]oleate but not [14C]linolenate. In monogalactolipid, about two-thirds of the labeled fatty acids were linolenate. In vivo desaturase activity was present in tissue of widely different levels of differentiation and chlorophyll content obtained from light-grown maize seedlings.

Documentos Relacionados

• Chloroplast Division and DNA Synthesis in Light-grown Wheat Leaves 1
• Development of Photosystem I and Photosystem II Activities in Leaves of Light-grown Maize (Zea mays) 1
• Control of Leaf and Stem Growth in Light-grown Pea Seedlings by Two High Irradiance Responses 1
• Influence of Cell Age on Chlorophyll Formation in Light-grown and Etiolated Wheat Seedlings 1
• Auxin Transport Is Required for Hypocotyl Elongation in Light-Grown but Not Dark-Grown Arabidopsis1