Characterization of a citrus vascular-specific zinc-binding cysteine proteinase inhibitor

Persistent Link:
http://hdl.handle.net/10150/298754
Title:
Characterization of a citrus vascular-specific zinc-binding cysteine proteinase inhibitor
Author:
Ellis, Danielle René
Issue Date:
1998
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:
A 712 bp partial cDNA clone (czbp- 1) of the citrus vascular zinc binding protein (CVZBP) was isolated using reverse transcriptase polymerase chain reaction (RT-PCR). The deduced amino acid sequence of czbp-1 was identical to the N-terminal amino acid sequence for the CVZBP. Czbp- 1 had a 549 bp open reading frame and two putative polyadenylation sites, +20 bp and +103 bp relative to the poly-A tail. The deduced amino acid sequence had identity with members of the Kunitz soybean proteinase inhibitor (KSPI) family. Many members of this family are present in high concentrations in storage organs such as seeds and tubers, increase in response to abiotic stress, and are considered defense or stress response proteins. The CVZBP did not appear to fit in this category. Unlike many members of the KSPI family CVZBP was not detected in citrus seeds and protein levels decreased in response to wounding. Transcript also decreased in response to osmotic stress; a similar result previously was reported for CVZBP protein levels. Accumulation of CVZBP and its transcript increased in Zn deficient citrus seedlings compared to those receiving sufficient levels of Zn, indicating that Zn nutrition can modulate CVZBP expression. Recombinant CVZBP was produced and used to determine the capacity of this protein to inhibit several types of proteinases. The CVZBP inhibited the cysteine proteinase, papain, but not the serine proteinases, trypsin and chymotrypsin. CVZBP protein was immunolocalized primarily to the xylem parenchyma in vascular tissue of citrus midribs. Based on these results it is possible that the CVZBP has a function in vascular differentiation. Cysteine proteinases were identified in developing tracheary elements in Zinnia cell cultures. Addition of inhibitors of cysteine proteinase to these cultures prior to secondary cell wall deposition prevents differentiation of the cells into tracheary elements. Perhaps cysteine proteinase inhibitors, such as the CVZBP, in the xylem, contribute to timing of tracheary element differentiation and determination.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Biology, Molecular.; Biology, Genetics.; Agriculture, Plant Culture.; Biology, Plant Physiology.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Plant Sciences
Degree Grantor:
University of Arizona
Advisor:
Taylor, Kathryn C.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleCharacterization of a citrus vascular-specific zinc-binding cysteine proteinase inhibitoren_US
dc.creatorEllis, Danielle Renéen_US
dc.contributor.authorEllis, Danielle Renéen_US
dc.date.issued1998en_US
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.abstractA 712 bp partial cDNA clone (czbp- 1) of the citrus vascular zinc binding protein (CVZBP) was isolated using reverse transcriptase polymerase chain reaction (RT-PCR). The deduced amino acid sequence of czbp-1 was identical to the N-terminal amino acid sequence for the CVZBP. Czbp- 1 had a 549 bp open reading frame and two putative polyadenylation sites, +20 bp and +103 bp relative to the poly-A tail. The deduced amino acid sequence had identity with members of the Kunitz soybean proteinase inhibitor (KSPI) family. Many members of this family are present in high concentrations in storage organs such as seeds and tubers, increase in response to abiotic stress, and are considered defense or stress response proteins. The CVZBP did not appear to fit in this category. Unlike many members of the KSPI family CVZBP was not detected in citrus seeds and protein levels decreased in response to wounding. Transcript also decreased in response to osmotic stress; a similar result previously was reported for CVZBP protein levels. Accumulation of CVZBP and its transcript increased in Zn deficient citrus seedlings compared to those receiving sufficient levels of Zn, indicating that Zn nutrition can modulate CVZBP expression. Recombinant CVZBP was produced and used to determine the capacity of this protein to inhibit several types of proteinases. The CVZBP inhibited the cysteine proteinase, papain, but not the serine proteinases, trypsin and chymotrypsin. CVZBP protein was immunolocalized primarily to the xylem parenchyma in vascular tissue of citrus midribs. Based on these results it is possible that the CVZBP has a function in vascular differentiation. Cysteine proteinases were identified in developing tracheary elements in Zinnia cell cultures. Addition of inhibitors of cysteine proteinase to these cultures prior to secondary cell wall deposition prevents differentiation of the cells into tracheary elements. Perhaps cysteine proteinase inhibitors, such as the CVZBP, in the xylem, contribute to timing of tracheary element differentiation and determination.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectBiology, Molecular.en_US
dc.subjectBiology, Genetics.en_US
dc.subjectAgriculture, Plant Culture.en_US
dc.subjectBiology, Plant Physiology.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplinePlant Sciencesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorTaylor, Kathryn C.en_US
dc.identifier.proquest9912107en_US
dc.identifier.bibrecord.b39123078en_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.