scholarly journals Short communications. The incorporation of (14C4)aspartic acid into nicotinic acid N-glucoside in Nicotiana tabacum

1971 ◽  
Vol 124 (5) ◽  
pp. 949-950 ◽  
Author(s):  
T A Scott ◽  
A L Devonshire
Keyword(s):  
Nicotiana Tabacum ◽  
Nicotinic Acid ◽  
Aspartic Acid

scholarly journals Nicotine Biosynthesis in Nicotiana: A Metabolic Overview

2019 ◽  
Vol 56 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Fernanda Fleig Zenkner ◽  
Márcia Margis-Pinheiro ◽  
Alexandro Cagliari
Keyword(s):  
Nicotiana Tabacum ◽  
Nicotinic Acid ◽  
Wild Species ◽  
Pyridine Ring ◽  
Aerial Part ◽  
Recent Literature ◽  
Alkaloid Production ◽  
Pyrrolidine Ring ◽  
Cortical Cells ◽  
Nicotine Biosynthesis

Alkaloids are important compounds found in Nicotiana plants, essential in plant defense against herbivores. The main alkaloid of Nicotiana tabacum, nicotine, is produced in roots and translocated to the leaves. Nicotine is formed by a pyrrolidine and a pyridine ring in a process involving several enzymes. The pyridine ring of nicotine is derived from nicotinic acid, whereas the pyrrolidine ring originates from polyamine putrescine metabolism. After synthesis in root cortical cells, a set of transporters is known to transport nicotine upward to the aerial part and store it in leaf vacuoles. Moreover, nicotine can be metabolized in leaves, giving rise to nornicotine through the N-demethylation process. Some Nicotiana wild species produce acyltransferase enzymes, which allow the plant to make N-acyl-nornicotine, an alkaloid with more potent insecticidal properties than nicotine. However, although we can find a wealth of information about the alkaloid production in Nicotiana spp., our understanding about nicotine biosynthesis, transport, and metabolism is still incomplete. This review will summarize these pathways on the basis on recent literature, as well as highlighting questions that need further investigation.

Tobacco Mosaic Virus-Infected Tissue

1985 ◽  
Vol 43 ◽  
pp. 510-511
Author(s):  
Egbert W. Henry
Keyword(s):  
Nicotiana Tabacum ◽  
Tobacco Mosaic Virus ◽  
Chlorogenic Acid ◽  
Mosaic Virus ◽  
Host Resistance ◽  
Oxidative Metabolism ◽  
Leaf Tissue ◽  
Vein Clearing ◽  
Basal Septum ◽  
Concentration Levels

Tobacco mosaic virus (TMV) infection has been studied in several investigations of Nicotiana tabacum leaf tissue. Earlier studies have suggested that TMV infection does not have precise infective selectivity vs. specific types of tissues. Also, such tissue conditions as vein banding, vein clearing, liquification and suberization may result from causes other than direct TMV infection. At the present time, it is thought that the plasmodesmata, ectodesmata and perhaps the plasmodesmata of the basal septum may represent the actual or more precise sites of TMV infection.TMV infection has been implicated in elevated levels of oxidative metabolism; also, TMV infection may have a major role in host resistance vs. concentration levels of phenolic-type enzymes. Therefore, enzymes such as polyphenol oxidase, peroxidase and phenylalamine ammonia-lyase may show an increase in activity in response to TMV infection. It has been reported that TMV infection may cause a decrease in o-dihydric phenols (chlorogenic acid) in some tissues.

Changes in polyamine synthesis during anther development and pollen germination in tobacco (Nicotiana tabacum)

1994 ◽  
Vol 92 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Fatiha Chibi ◽  
Angel Jesus Matilla ◽  
Trinidad Angosto ◽  
Dolores Garrido
Keyword(s):  
Nicotiana Tabacum ◽  
Pollen Germination ◽  
Anther Development ◽  
Polyamine Synthesis
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