University of California

Phloem anatomy of tobacco affected with curly top and mosaic


Katherine Esau

Author Affiliations

Katherine Esau was Assistant Professor of Botany and Assistant Botanist in the Experiment Station.

Publication Information

Hilgardia 13(8):435-490. DOI:10.3733/hilg.v13n08p435. January 1941.

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The phloem of plants affected by the curly-top disease undergoes profound histologic and cytologic changes. Among these, the degeneration and death of certain cells and the hyperplastic increase in the number of sieve-tube elements are the most striking symptoms (Esau, 1933), (1935a), (1935b).3 The inception of phloem degeneration in a developing organ depends on the presence of mature sieve tubes, while the first internal symptoms are localized in areas directly connected by phloem with the inoculated leaf (Esau, 1935a), (1935b).

The interpretation of the nature of phloem degeneration in curly-top plants has been based almost entirely upon studies of a single host, the sugar beet (Esau, 1933), (1935a), (1935b); (Artschwager and Starrett, 1936); a limited consideration of the anatomy of curly-top tobacco showed comparable pathologic changes in this host (Bennett and Esau, 1936).

The present paper is a result of rather comprehensive studies on the phloem of the Turkish variety of Nicotiana Tabacum affected with curly top. It also briefly considers phloem degeneration in tomato affected by the same disease and compares the effects of curly top and of tobacco mosaic upon the phloem of tobacco.

Nicotiana Tabacum was selected for study because this species has served repeatedly in investigations concerning translocation and tissue relations of the curly-top virus (Bennett, 1934), (1937); (Bennett and Esau, 1936). At the same time, the choice of tobacco offered an opportunity to examine the course of phloem degeneration in a plant that differed considerably from the sugar beet in its development, its morphology, and its reaction to the curly-top virus. Tobacco, unlike the beet, produces a stem with secondary vascular tissues during the first year of growth, has internal phloem and no specialized underground storage organ nor anomalous secondary growth. With regard to curly-top infection, tobacco commonly recovers from the disease (Bennett, 1934); (Wallace, 1939), a tendency not characteristic of the sugar beet.

Literature Cited

Artschwager E., Starrett R. C. Histological and cytological changes in sugar-beet seedlings affected with curly top. Jour. Agr. Res. 1936. 53:637-57.

Askenasy E. Ueber eine neue Methode, um die Vertheilung der Wachsthumsintensität in wachsenden Teilen zu bestimmen. Verhandl. Naturhist.-Medicin. Vereins Heidelberg. 1880. 2:70-153.

Bennett C. W. Plant-tissue relations of the sugar-beet curly-top virus. Jour. Agr. Res. 1934. 48:665-701.

Bennett C. W. Correlation between movement of the curly top virus and translocation of food in tobacco and sugar beet. Jour. Agr. Res. 1937. 54:479-502.

Bennett C. W. Relation of food translocation to movement of virus of tobacco mosaic. Jour. Agr. Res. 1940. 60:361-90.

Bennett C. W., Esau K. Further studies on the relation of the curly-top virus to plant tissues. Jour. Agr. Res. 1936. 53:595-620.

Crafts A. S. Movement of viruses, auxins, and chemical indicators in plants. Bot. Rev. 1939. 5:471-504. DOI: 10.1007/BF02878444 [CrossRef]

Esau K. Pathologic changes in the anatomy of leaves of the sugar-beet, Beta vulgaris L., affected by curly top. Phytopathology. 1933. 23:679-712.

Esau K. Ontogeny of the phloem in sugar beets affected by the curly-top disease. Amer. Jour. Bot. 1935a. 22:149-63. DOI: 10.2307/2436006 [CrossRef]

Esau K. Initial localization and subsequent spread of curly-top symptoms in the sugar beet. Hilgardia. 1935b. 9(8):397-436. DOI: 10.3733/hilg.v13n08p435 [CrossRef]

Esau K. Ontogeny and structure of the phloem of tobacco. Hilgardia. 1938a. 11(8):343-424. DOI: 10.3733/hilg.v13n08p435 [CrossRef]

Esau K. The multinucleate condition in fibers of tobacco. Hilgardia. 1938b. 11(8):427-34. DOI: 10.3733/hilg.v13n08p435 [CrossRef]

Esau K. Some anatomical aspects of plant virus disease problems. Bot. Rev. 1938c. 4:548-79. DOI: 10.1007/BF02870116 [CrossRef]

Esau K. Development and structure of the phloem tissue. Bot. Rev. 1939. 5:373-432. DOI: 10.1007/BF02878295 [CrossRef]

Esau K. Developmental anatomy of the fleshy storage organ of Daucus carota. Hilgardia. 1940. 13(5):175-226. DOI: 10.3733/hilg.v13n08p435 [CrossRef]

Goldstein Bessie. A cytological study of the leaves and growing points of healthy and mosaic diseased tobacco plants. Torrey Bot. Club Bul. 1926. 53:499-599. DOI: 10.2307/2480367 [CrossRef]

Priestley J. H., Scott L. I. Phyllotaxis in the dicotyledon from the standpoint of developmental anatomy. Biol. Rev. 1933. 8:241-68. DOI: 10.1111/j.1469-185X.1933.tb01089.x [CrossRef]

Priestley J. H., Scott L. I. An introduction to botany with special reference to the structure of the flowering plant. 1938. London: Longmans, Green and Co. 615p.

Wallace James M. Recovery from and acquired tolerance of curly top in Nicotiana tabacum. Phytopathology. 1939. 29:743-49.

Esau K. 1941. Phloem anatomy of tobacco affected with curly top and mosaic. Hilgardia 13(8):435-490. DOI:10.3733/hilg.v13n08p435
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