STEM ABSCISSION IN THE TUMBLEWEED, PSORALEA'

A B S T R A C T Abscission was studied in Psoralea argophylla Ptursh, a prairie tumbleweed. This process is responsible for the detachment of the stem from its perennial base. In a single plant abscission may proceed through one or more intercalary meristems located at or near ground level. During senescence a separation layer differentiates within each of these meristems. Chemical changes occur within the compound middle lamellae which result in the conversionl of insoluble pectic compounds into soluble forms. Cell separation takes place only after removal of the pectic compounds, meristematic activity, and attenuation of cell walls. Unlike reports of other angiosperms the protective layer is not formed adjacent to the separation layer, btut forms some distance undergrouind at the stem-root junction.

[1]  A. Spurr,et al.  ABSCISIN, AUXIN, AND GIBBERELLIN EFFECTS ON THE DEVELOPMENTAL ASPECTS OF ABSCISSION IN COTTON (GOSSYPIUM HIRSUTUM) , 1967 .

[2]  A. Leopold,et al.  The Nature of Leaf Abscission , 1964, The Quarterly Review of Biology.

[3]  W. Jacobs.  Longevity of Plant Organs: Internal Factors Controlling Abscission , 1962 .

[4]  P. Albersheim,et al.  STAINED PECTIN AS SEEN IN THE ELECTRON MICROSCOPE , 1960, The Journal of Biophysical and Biochemical Cytology.

[5]  E. F. Jansen,et al.  Pectic Metabolism of Growing Cell Walls. , 1960, Plant physiology.

[6]  C. Leinweber,et al.  Foliar Abscission in Cotton. III. Macroscopic and Microscopic Changes Associated with Natural and Chemically Induced Leaf-Fall , 1959, Botanical Gazette.

[7]  R. Reeve.  HISTOLOGICAL AND HISTOCHEMICAL CHANGES IN DEVELOPING AND RIPENING PEACHES. II. THE CELL WALLS AND PECTINS , 1959 .

[8]  R. Reeve,et al.  Measurement of Plant Pectic Substances, Reaction of Hydroxylamine with Pectinic Acids. Chemical Studies and Histochemical Estimation of the Degree of Esterification of Pectic Substances in Fruit , 1959 .

[9]  P. A. Roelofsen.  The plant cell-wall , 1959 .

[10]  S. Bayley,et al.  Chemical Constitution of the Primary Cell Walls of Avena Coleoptiles. , 1958, Plant physiology.

[11]  S. Siegel.  On the Biosynthesis of Lignins , 1953 .

[12]  V. Facey.  ABSCISSION OF LEAVES IN FRAXINUS AMERICANA L. , 1950 .

[13]  G. S. Avery,,et al.  Leaf abscission and the so-called " abscission layer ". , 1950 .

[14]  Monroe McCown.  Anatomical and Chemical Aspects of Abscission of Fruits of the Apple , 1943, Botanical Gazette.

[15]  R. Myers.  Effect of Growth Substances on the Absciss Layer in Leaves of Coleus , 1940, Botanical Gazette.

[16]  H. Hornich,et al.  Automorphic functions , 1935 .

[17]  C. P. Dutt.  Abscission in Cotton Flowers , 1928, Botanical Gazette.

[18]  H. Pfeiffer.  Die pflanzlichen Trennungsgewebe , 1928 .

[19]  L. H. Macdaniels,et al.  An introduction to plant anatomy , 1925 .

[20]  H. C. Sampson.  Chemical Changes Accompanying Abscission in Coleus Blumei , 1918, Botanical Gazette.

[21]  E. Lee.  The Morphology of Leaf-fall , 1911 .