(1981). Naturally Occurring Toxic Alkaloids in Foods. CRC Critical Reviews in Toxicology: Vol. 9, No. 1, pp. 21-104.

Naturally occurring toxic alkaloids in foods.

Plant cells contain a unique class of organelles, designated the plastids, which distinguish them from animal cells. According to the largely accepted endosymbiotic theory of evolution, plastids are descendants of prokaryotes. This process requires several adaptative changes which involve the maintenance and the expression of part of the plastid genome, as well as the integration of the plastid activity to the cellular metabolism. This is illustrated by the diversity of plastids encountered in plant cells. For instance, in tissues undergoing color changes, i.e., flowers and fruits, the chromoplasts produce and accumulate excess carotenoids. In this paper we attempt to review the basic aspects of chromoplast development.

Biochemistry and molecular biology of chromoplast development.

The chemical contituents are concerned in the quality of tomato fruit in respect to color, texture, flavor, nutritive value, and wholesomeness. In general, high sugar contents, redness of color, and firm texture are associated with prominence of rich flavor. Biochemical changes as influenced by growth, maturation, and environment of tomato fruit are discussed.

Quality and nutritional composition of tomato fruit as influenced by certain biochemical and physiological changes

The glycoalkaloid composition of eggplants, tomatoes, and potatoes is discussed with specific reference to history, occurrences, factors affecting levels, control of accumulation, analysis, and toxicity.

Glycoalkaloids in solanaceae

There have been few studies on quantifying carotenoid accumulation in carrots, and none have taken the comparative approach. The abundance and distribution of carotenes in carrot roots of three varieties, white, orange, and high carotene mass (HCM) were compared using light and transmission electron microscopy (TEM). Light microscopy has indicated that, in all three varieties, carotenes were most abundant in the secondary phloem and this area was selected for further TEM analysis. While carotenes were extracted during the fixation process for TEM, the high-pressure freezing technique we employed preserved the spaces (CS) left behind by the extracted carotene crystals. Chromoplasts from the HCM variety contained significantly (P < 0.05) more CS than chromoplasts from the orange variety. Chromoplasts from the white variety had few or no CS. There was no significant difference between the HCM and orange varieties in the number of chromoplasts per unit area, but the white variety had significantly (P < 0.05) fewer chromoplasts than the other two varieties. A large number of starch-filled amyloplasts was observed in secondary phloem of the white variety but these were not found in the other two varieties. The results from this comparative approach clearly define the subcellular localization of carotenoids in carrot roots and suggest that while the HCM genotype was selectively bred for increased carotene content, this selection did not lead to increased numbers of carotene-containing chromoplasts but rather greater accumulation of carotene per chromoplast. Furthermore, the results confirm that roots of the white carrot variety retain residual amounts of carotene.

Chromoplasts ultrastructure and estimated carotene content in root secondary phloem of different carrot varieties

Nachweis, dass die Blattbehandlung mit subletaler Konzentration von Simazin, Propazin, Igran und Prometon die Protein-Synthese bei Erbse und Mais vermehrt. Die Blattbehandlung mit Simazin zerstorte die Ultrastruktur des Samenlappens bei der Erbse.

Effects ofs-triazines on protein synthesis in leaves of peas (Pisum sativum L.) and sweet corn (Zea mays L.) and on the ultrastructure of pea cotyledons

Der Wuchs und die Sporenbildung der PilzePenicillium expansum, Rhizopus nigricans, Aspergillus niger, Botrytis alli undAlternaria wurde durch den subatmospharischen Druck gehemmt.

Fungistatic effects of sub-atmospheric pressures

Wenn der Boden vor der Aussaat vonDaucus carota L mit Telon und Nemagon behandelt wurde, konnten Strukturveranderungen in den Chromoplasten der Karottenwurzeln festgestellt werden

Influence of soil fumigation of telone and nemagon on the ultrastructure of chromoplasts in carrot roots (Daucus carota L.)

Die neutrale Fraktion gruner Tomatenfruchte zeigt nach Futterung mit C14O2 im Licht eine hohere Radioaktivitat als nach der Futterung im Dunkeln. Die grune Tomatenfrucht ist zur Photosynthese befahigt.

Ripening tomatoes: C14O2 uptake by green tomato fruit.

Behandlung der Sprossknollen mit Benzyladenin fordert die Glykoalkaloidbildung der Solanaceen. Je nach Extraktionsmethode konnen unidentifizierte Alkaloide nachgewiesen werden.

D. K. Salunkhe

Papers

Effects ofs-triazines on protein synthesis in leaves of peas (Pisum sativum L.) and sweet corn (Zea mays L.) and on the ultrastructure of pea cotyledons

Fungistatic effects of sub-atmospheric pressures

Influence of soil fumigation of telone and nemagon on the ultrastructure of chromoplasts in carrot roots (Daucus carota L.)

Ripening tomatoes: C14O2 uptake by green tomato fruit.

Effects of N6-benzyladenine on glycoalkaloids in potatoes as determined by thin layer chromatography