Publication Date

1990

Document Type

Dissertation/Thesis

First Advisor

Johns, Mitrick A.

Degree Name

M.S. (Master of Science)

Department

Department of Biological Sciences

LCSH

Phosphates||Corn--Physiology

Abstract

Phosphate-stress was determined in the monocot Zea mays. Definition of phosphate-stress was investigated by growing plants with and without phosphate in defined nutrient solution and measuring a number of parameters. These parameters included (1) measurements of shoot and root, (2) weight of shoot and root, (3) phosphatase activity present in the root, and (A) total phosphate levels of shoot and root. Conclusions of this study showed that phosphate-stressed corn had increased root growth, while shoot growth decreased. Not only were phosphate-starved roots longer, but they were less massive and less branching than phosphate-rich roots. Phosphatase secretion increased A-fold in roots starved for phosphate. Threshold for phosphate-stress has been determined to occur between 5uM and 15uM phosphate. The soluble phosphatase secreted from the root surface has been partially purified by ion-exchange chromatography. An acid and an alkaline phosphatase with pH optima 5.5 and 7.5, respectively, were demonstrated.

Comments

Includes bibliographical references (pages [60]-68)

Extent

68 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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