Hostname: page-component-8448b6f56d-c47g7 Total loading time: 0 Render date: 2024-04-18T12:25:05.661Z Has data issue: false hasContentIssue false
  • English
  • Français

Bicellular Trichomes of Johnsongrass (Sorghum halepense) Leaves: Morphology, Histochemistry, and Function

Published online by Cambridge University Press:  12 June 2017

Chester G. McWhorter ,
Rex N. Paul  and
J. Clark Ouzts
Chester G. McWhorter
Affiliation:
Appl. Tech. Res. Unit
Rex N. Paul
Affiliation:
Weed Biol. and Manage. Res. Unit., So. Weed Sci. Lab.
J. Clark Ouzts
Affiliation:
Appl. Tech. Res. Unit, USDA-ARS, Stoneville, MS 38776
Get access Rights & Permissions [Opens in a new window]

Abstract

Studies were conducted of one of the structural factors that influences microroughness on johnsongrass leaves. Bicellular trichomes, 47 ± 5 μm long, represented 4 to 5% of all epidermal cells. They secreted a mucilagenous material that covered 8 ± 4% of the leaf surface. Bicellular trichomes occurred in longitudinal rows, intermixed with intercostal cork-silica cells, between rows of stomata. Numbers of bicellular trichomes present per unit area were inversely related to numbers of intercostal cork-silica cells. The trichomes were the panicoid type that are reported not to secrete salts. Johnsongrass trichomes, however, could be induced to discharge salt in the mucilage-type secretions when plants were grown in a soil mixture that was high in lime. Not all secretory constituents were identified, but carbohydrates and callose were found in addition to possible low concentrations of protein. The apical or cap cell of the trichomes stained positively for lipid, protein, and polysaccharide and negatively for pectin, polyphenols, steroids, and alkaloids. The presence of trichomes increases leaf surface microroughness, but the secretion covers wax crystals, decreasing leaf microroughness and likely providing another barrier to herbicide entry through the cuticle. Bicellular trichomes on grain sorghum were similar to those on johnsongrass and also discharged secretions on the leaf surface.

Keywords

johnsongrass, Sorghum halepense (L.) Pers. #3 SORHAgrain sorghum, Sorghum bicolor (L.) ‘Funks G522.’Leaf surface morphologymicrohairssalt glandssecretory trichomesSORHA
Type
Weed Biology and Ecology
Information
Weed Science , Volume 43 , Issue 2 , June 1995 , pp. 201 - 208
Copyright
Copyright © 1995 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

LITERATURE CITED

1. Amarasinghe, V. 1990. Polysaccharides and protein secretion by plant microhairs. A cytochemical study at light and electron microscopic levels. Protoplasma 156:45–56.Google Scholar
2. Amarasinghe, V. and Watson, L. 1988. Comparative ultrastructure of microhairs in grasses. Bot. J. Linnean Soc. 98:303–319.Google Scholar
3. Amarasinghe, V. and Watson, L. 1989. Variation in salt secretory activities of microhairs in grasses. Aust. J. Plant Physiol. 16:219–229.Google Scholar
4. Boize, L., Gudin, C., and Purdue, C. 1976. The influence of leaf surface roughness on the spreading of oil spray drops. Ann. Appl. Biol. 84:205–211.Google Scholar
5. Cain, A. J. 1947. The use of Nile blue in the examination of lipoids. Q. J. Microsc. Sci. 88:383–392.Google Scholar
6. Cawood, A. H., Potter, V., and Dickinson, H. C. 1978. An evaluation of Coomassie brilliant blue as a stain for quantitative microdensitometry of protein in sections. J. Histochem. Cytochem. 26:64–650.Google Scholar
7. Chayen, J., Bitensky, L., and Butcher, R. G. 1973. Practical Histochemistry. New York, Wiley. 171 pp.Google Scholar
8. Cutter, E. G. 1978. Plant Anatomy. Addison-Wesley Pub. Co., London. 315 pp.Google Scholar
9. Egley, G. H., Paul, R. N, and Lax, A. R. 1986. Seed coat imposed dormancy. Histochemistry of the region controlling onset of water entry into Sida spinosa seeds. Physiol. Plant. 67:320–327.Google Scholar
10. Ellis, R. P. 1979. A procedure for standardizing comparative leaf anatomy in the Poaceae. II. The epidermis as seen in surface view. Bothalia 12:641–671.Google Scholar
11. Esau, K. 1953. Phloem. Page 275–303 in Plant Anatomy. John Wiley and Sons, Inc., New York.Google Scholar
12. Fahn, A. 1974. Plant Anatomy, 2nd ed. Pergamon Press, Oxford, U.K. 294 pp.Google Scholar
13. Fahn, A. 1988. Secretory tissues in vascular plants. New Phytol. 108:229–257.Google Scholar
14. Hardman, R. and Sofowora, E. A. 1972. Antimony trichloride as a test reagent for steroids, especially diosgenin and yamogenin, in plant tissue. Stain Tech. 47:205–208.Google Scholar
15. Holloway, P. J. 1970. Surface factors affecting the wetting of leaves. Pestic. Sci. 1:156–163.Google Scholar
16. Jensen, W. A. 1962. Botanical Histochemistry: Principles and Practice. W. H. Freeman and Co., San Francisco. 408 pp.Google Scholar
17. Johnston, C. R. and Watson, L. 1976. Microhairs: a universal characteristic of nonfestucoid grass genera? Phytomorphology 26:297–301.Google Scholar
18. Levering, C. A. and Thompson, W. W. 1971. The ultrastructure of the salt gland of Spartina foliosa . Planta 97:183–196.Google Scholar
19. Levering, C. A. and Thompson, W. W. 1972. Studies on the ultrastructure and mechanism of secretion of the salt gland of the grass Spartina . Proc. Elec. Micro. Soc. Am. 30:222–223.Google Scholar
20. Mazia, D., Brewer, P. A., and Alfert, M. 1953. The cytochemical staining and measurement of protein with mercuric bromphenol blue. Biol. Bull. 104:57–67.CrossRefGoogle Scholar
21. Metcalfe, C. R. 1960. Anatomy of monocotyledons, Vol. I. Gramineae. Clarendon Press, Oxford. 731 pp.Google Scholar
22. McManus, J. F. A. 1948. Histological and histochemical use of periodic acid. Stain Technol. 23:99–108.Google Scholar
23. McWhorter, C. G. 1971. Anatomy of johnsongrass. Weed Sci. 19:385–393.Google Scholar
24. McWhorter, C. G. and Paul, R. N. 1989. The involvement of cork-silica cell pairs in the production of wax filament in johnsongrass (Sorghum halepense). Weed Sci. 37:458–470.Google Scholar
25. McWhorter, C. G., Ouzts, C., and Paul, R. N. 1993. Micromorphology of johnsongrass (Sorghum halepense) leaves. Weed Sci. 41:583–58.Google Scholar
26. Mowry, R. W. 1956. Alcian blue technics for the histochemical study of acidic carbohydrates. J. Histochem. 4:407.Google Scholar
27. Mowry, R. W. 1960. Revised method producing improved coloration of acidic polysaccharides with Alcian Blue 8GX supplied currently. J. Histochem. Cytochem. 8:323.Google Scholar
28. Oross, J. W. and Thompson, W. W. 1982. The ultrastructure of salt glands of Cynodon and Distichlis (Poaceae). Am. J. Bot. 69:939–949.Google Scholar
29. Paul, R. N., McWhorter, C. G., and Ouzts, J. C. 1990. An investigation into the ultrastructural histochemistry of glandular trichomes of johnsongrass [Sorghum halepense (L.) Pers.] leaves. Proc. Elect. Micro. Soc. Am. 50:842–843.Google Scholar
30. Reeve, R. M. 1951. Histochemical tests for polyphenols in plant tissue. Stain Technol. 26:91–96.Google Scholar
31. Sterling, T. M., Houtz, R. L., and Putnam, A. R. 1987. Phytotoxic exudates from velvetleaf (Abutilon theophrasti) glandular trichomes. Am. J. Bot. 74:543–550.Google Scholar
32. Tateoka, T., Inoue, S., and Kawano, S. 1959. Notes on some grasses IX: systematic significance of bicellular microhairs of leaf epidermis. Bot. Gaz. 121:80–91.Google Scholar
33. Wagner, G. J. 1991. Secreting glandular trichomes: more than just hairs. Plant Physiol. 96:675–679.Google Scholar
34. Werker, E. and Fahn, A. 1981. Secretory hairs of Inula viscosa (L.) AIT—Development, ultrastructure, and secretion. Bot. Gaz. 142:461–476.Google Scholar