Relationships Between Expression of Heat Shock Protein Genes and Photosynthetic Behavior During Drought Stress in Plants

Simple item page
dc.contributor.authorVasquez-Robinet, Ceciliaen
dc.contributor.committeechairGrene, Ruthen
dc.contributor.committeememberBeers, Eric P.en
dc.contributor.committeememberGillaspy, Glenda E.en
dc.contributor.committeememberHeath, Lenwood S.en
dc.contributor.departmentPlant Pathology, Physiology, and Weed Scienceen
dc.date.accessioned2014-03-14T20:10:05Zen
dc.date.adate2007-04-26en
dc.date.available2014-03-14T20:10:05Zen
dc.date.issued2007-04-10en
dc.date.rdate2010-04-26en
dc.date.sdate2007-04-19en
dc.description.abstractHeat shock proteins (HSPs) are expressed in response to environmental stresses. Compared to other kingdoms, plant HSP families are larger, presumably the result of adaptation to a wide range of stresses. Following on an analysis of drought stress characteristics in loblolly pine (Watkinson et al., 2003), expression patterns of HSP gene expression during photosynthetic acclimation were examined. One cycle of mild (-1Mpa) followed by two cycles of severe stress (-1.7Mpa) were probed for conditioning effects. Photosynthetic acclimation occurred after the first cycle. No acclimation occurred without the first mild cycle. Microarray/RT-PCR analyses showed that a pine homolog to GRP94 (ER-resident HSP90) was up-regulated after rehydration coincident with acclimation. This GRP94 is closely related to GRP94 from the desiccation tolerant plant X. viscosa, supporting the importance of this gene during acclimation to water deficit. HSP genes whose products localized to the mitochondrion showed gradual up-regulation after consecutive cycles of severe drought. The Arabidopsis pine GRP94 homolog, (AtHSP90-7) was then analyzed, using bioinformatics (Pati et al., 2006) and laboratory tools. Genes encoding putative candidate co-chaperones for GRP94 and other HSP90s were discovered, which contained water stress-related cis-elements. Arabidopsis (Col-0) wild type and two T-DNA insertion mutants in HSP90-7 were used to study the importance of this gene for photosynthetic acclimation. Only the mutants were able to acclimate to drought stress, with the level of AtHSP90-7 expression in the mutants being reduced compared to the wild type. AtHSP90-7 may have a different role in Arabidopsis, and its reduced expression activated other protective genes (Klein et al., 2006). Responses to extreme drought in resistant (Sullu) and susceptible (Negra Ojosa) lines of Andean potatoes were also compared in order to identify relationships between HSPs gene expression, and tolerance, defined as the ability to maintain photosynthesis at 50% after 25 days of drought and to recover from the stress. Tolerance was correlated with up-regulation of HSPs (mostly chaperonins) and antioxidant genes all of whose gene products are located in the chloroplast.en
dc.description.degreePh. D.en
dc.identifier.otheretd-04192007-083407en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-04192007-083407/en
dc.identifier.urihttp://hdl.handle.net/10919/27009en
dc.publisherVirginia Techen
dc.relation.haspartDissertationCVR.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectHSP90en
dc.subjectphotosynthesisen
dc.subjectandean potatoen
dc.subjectdrought stressen
dc.subjectLoblolly pineen
dc.subjectArabidopsisen
dc.subjectGRP94en
dc.titleRelationships Between Expression of Heat Shock Protein Genes and Photosynthetic Behavior During Drought Stress in Plantsen
dc.typeDissertationen
thesis.degree.disciplinePlant Pathology, Physiology, and Weed Scienceen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
DissertationCVR.pdf
Size:
2.28 MB
Format:
Adobe Portable Document Format
Download

Collections

Doctoral Dissertations