Function of Root Border Cells and their Exudates on Plant Defense in Hydroponic Systems

Persistent Link:
http://hdl.handle.net/10150/202535
Title:
Function of Root Border Cells and their Exudates on Plant Defense in Hydroponic Systems
Author:
Curlango-Rivera, Gilberto
Issue Date:
2011
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Controlled environment agriculture offers a solution to challenges including less available land, water deficits, and consumer demand for pesticide free produce. However, control of soil-borne diseases is a major limiting factor. The goal of this dissertation was to examine predictions of the hypothesis that border cells function to protect plant health by controlling microorganisms associated with plants grown in hydroponic culture. Border cells separate from root tips upon immersion in water, and appear to have important roles in the defense mechanisms of plant roots. The general objectives were (1) to study the delivery of border cells in hydroponics; (2) to evaluate interactions between border cells and microorganisms in hydroponics; and (3) to explore approaches to alter border cell production for improved root disease control. In this study it was confirmed that border cells can be released continuously into the solution of hydroponic culture suggesting that plants grown in this system may use extra energy in the production of new border cells. Free border cells interacted with microorganisms present in the hydroponic solution by secreting an extracellular capsule. Previous studies showed that proteins are a key component of this capsule, including lectins. The interaction of pea lectin and Nectria haematococca spores therefore was explored. Results demonstrated that pea lectin agglutinates fungal spores in a hapten-specific manner, and inhibits their germination. Lectin had no negative effect on root development suggesting that it could be used as a potential control for soil-borne diseases in hydroponics. To control the production of border cells, subsequent studies measured the impact of a transient exposure of root tips to different metabolites secreted by root caps and border cells. Exposure to specific metabolites altered the production of border cells without measurable effects on root growth and development. This is in contrast to results obtained with altered gene expression. For example, gene silencing of a border cell specific gene resulted in altered root growth.
Type:
text; Electronic Dissertation
Keywords:
Greenhouses; Hydroponics; Plant Roots; Rhizosphere; Plant Pathology; Border cells; Extracellular molecules
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Plant Pathology
Degree Grantor:
University of Arizona
Advisor:
Hawes, Martha C.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleFunction of Root Border Cells and their Exudates on Plant Defense in Hydroponic Systemsen_US
dc.creatorCurlango-Rivera, Gilbertoen_US
dc.contributor.authorCurlango-Rivera, Gilbertoen_US
dc.date.issued2011-
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractControlled environment agriculture offers a solution to challenges including less available land, water deficits, and consumer demand for pesticide free produce. However, control of soil-borne diseases is a major limiting factor. The goal of this dissertation was to examine predictions of the hypothesis that border cells function to protect plant health by controlling microorganisms associated with plants grown in hydroponic culture. Border cells separate from root tips upon immersion in water, and appear to have important roles in the defense mechanisms of plant roots. The general objectives were (1) to study the delivery of border cells in hydroponics; (2) to evaluate interactions between border cells and microorganisms in hydroponics; and (3) to explore approaches to alter border cell production for improved root disease control. In this study it was confirmed that border cells can be released continuously into the solution of hydroponic culture suggesting that plants grown in this system may use extra energy in the production of new border cells. Free border cells interacted with microorganisms present in the hydroponic solution by secreting an extracellular capsule. Previous studies showed that proteins are a key component of this capsule, including lectins. The interaction of pea lectin and Nectria haematococca spores therefore was explored. Results demonstrated that pea lectin agglutinates fungal spores in a hapten-specific manner, and inhibits their germination. Lectin had no negative effect on root development suggesting that it could be used as a potential control for soil-borne diseases in hydroponics. To control the production of border cells, subsequent studies measured the impact of a transient exposure of root tips to different metabolites secreted by root caps and border cells. Exposure to specific metabolites altered the production of border cells without measurable effects on root growth and development. This is in contrast to results obtained with altered gene expression. For example, gene silencing of a border cell specific gene resulted in altered root growth.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectGreenhousesen_US
dc.subjectHydroponicsen_US
dc.subjectPlant Rootsen_US
dc.subjectRhizosphereen_US
dc.subjectPlant Pathologyen_US
dc.subjectBorder cellsen_US
dc.subjectExtracellular moleculesen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplinePlant Pathologyen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorHawes, Martha C.en_US
dc.contributor.committeememberVanEtten, Hans D.en_US
dc.contributor.committeememberKubota, Chierien_US
dc.contributor.committeememberOlsen, Mary W.en_US
dc.contributor.committeememberHawes, Martha C.en_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.