Tissue and Cell-Type Localization and Partial Characterization of a Xylem Papain-Type Cysteine Protease From Arabidopsis

Cysteine proteases are associated with xylem tracheary element differentiation. XCP1 was recently identified as a xylem-specific cysteine protease in Arabidopsis (Zhao, et al., 2000). For this study a recombinant polyhistidine-tagged XCP1 (XCP1H6) was expressed and purified from an E. coli expression system. A polyclonal anti-XCP1 antibody was produced using purified XCP1H6. Immunoblot analysis of a developmental time course of xylem and bark protein extracted from root-hypocotyl segments demonstrated that XCP1 was expressed in xylem only. Further analysis under optimized immunoblot conditions, however, revealed that anti-XCP1 antibody reacted with protein present in both xylem and bark. The vast majority of immunoreactivity, however, was restricted to xylem. Cell-type localization of GUS expression under the control of a putative XCP1 promoter indicated that the XCP1 promoter specifies expression of XCP1 in tracheary elements in leaves, stems, roots and flowers. XCP1 promoter-driven GUS activity was not associated with senescing tissues.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Horticulture

Department dc:contributor.department

Horticulture

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2000

Author dc:creator

• Kositsup, Boonthida

Chair dc:contributor.committeechair

• Beers, Eric P.

Committee members dc:contributor.committeemember

• Welbaum, Gregory E.
• Hess, John L.

• programmed cell death
• cysteine protease
• Arabidopsis thaliana
• tracheary element
• xylem
• localization

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-04262000-17260046

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/31923