Graduate Thesis Or Dissertation
 

Water relations, stomatal conductance, and abscisic acid content of container-grown apple (Malus domestica Borkh.) plants in response to sorbitol-induced osmotic stress

Öffentlich Deposited

Herunterladbarer Inhalt

PDF Herunterladen
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/ng451k771

Descriptions

Attribute NameValues
Creator
Abstract
  • Sorbitol-induced osmotic stress (SIOS) to the root was found to be effective in reducing transpirational water loss in plants during water stress. Mechanisms of SIOS in stomatal control were investigated in containerized apples (Malus domestica Borkh. 'Gala'/M26) when leaf water potential (Ψw), osmotic potential (Ψs), turgor potential (Ψp), stomatal conductance (gs), relative water content (RWC), and abscisic acid (ABA) content of the leaf and xylem sap were determined. Sorbitol (-1.2 MPa) was applied as a soil drench. For ABA determination, crude leaf extract and xylem sap were used for the radioimmunoassay method. Stomatal conductance decreased rapidly within one hr after SIOS treatment, which was closely associated with a decline in leaf water status Ψw, Ψp, and RWC). The SlOS-induced earlier reduction in gs caused plants to resist greater desiccation stress than the untreated controls. Leaf ABA production was stimulated by SIOS treatment, but the effect differed between plants adapted in greenhouse and outdoor conditions. In greenhouse-adapted plants, SIOS caused leaf ABA to increase significantly two hrs after treatment, but had no effect in outdoor-adapted plants. However, gs was similarly reduced in both conditions by about 55%. This difference in leaf ABA production between plants adapted in both conditions could be associated with the concurrent differential decrease in Ψp; baseline Ψp was much higher in the outdoor-adapted plants than in the greenhouse-adapted plants. In the greenhouse-adapted plants, Ψp decreased by 61% (from 1.15 to 0.45 MPa) within two hrs after SIOS treatment, whereas Ψp decreased by 27% (from 2.15 to 1.58 MPa) in the outdoor-adapted plants. Xylem sap ABA, measured two hrs after SIOS treatment from the outdoor-adapted plants, was not affected, whereas gs and leaf Ψw (thus Ψp) significantly decreased. Significant increase in ABA content in the xylem sap and leaf, however, occurred 1 and 3 days after treatment, respectively. ABA level and gs data suggested that the immediate reduction in gs by SIOS treatment may have resulted from hydraulic effects on gs, rather than chemical effects (e.g., root ABA signal), at least for the outdoor-adapted plants.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Urheberrechts-Erklärung
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome, 24-bit Color) using Scamax Scan+ V.1.0.32.10766 on a Scanmax 412CD by InoTec in PDF format. LuraDocument PDF Compressor V.5.8.71.50 used for pdf compression and textual OCR.
Replaces

Beziehungen

Parents:

This work has no parents.

In Collection:

Artikel

Miniaturansicht Titel Hochladedatum Sichtbarkeit Aktionen
file details GUAKSUNGHEE1998.pdf 2017-08-02 Öffentlich Herunterladen