Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.554324
Title: Inhibition of Arabidopsis root growth by jasmonate
Author: Kunpratum, Narisa
Awarding Body: University of East Anglia
Current Institution: University of East Anglia
Date of Award: 2011
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Abstract:
Jasmonates (JAs) are plant hormones produced in plants during normal development and during exposure to stresses. JAs are required for plant development and defense. Stresses such as wounding the leaves increase the endogenous JA level and stunt plant growth. Exogenous JA reduces size of leaves and roots. The present study reports that the mechanism of JA-induced root growth inhibition was by reducing mitosis in the RAM and reducing cell elongation in the root elongation zone. Moreover, this study indicates a novel role for auxin in the JA-induced inhibition of root growth: JA reduced exogenous auxin-induced DR5::GUS expression and suppressed acropetal and basipetal auxin transport. Furthermore, under stresses such as wounding and salinity, the JA biosynthesis mutant aos had less inhibition of root growth than wild type, indicating a role for endogenous JA in response to these stresses. The root growth inhibition by JA involves other hormone signaling pathways, including GA, ABA, and auxin. For example, JA and GA had antagonistic effects in the regulation of root growth and COIl was partially required for root growth response to GA. COIl or endogenous JA signaling suppressed the inhibition of germination by ABA. MeJA induced flavonoid acted as an auxin inhibitor by causing an inhibition of auxin transport in roots. JA was found to interact with light in the regulation of plant defence and development. This study presents evidence that JA partially mimiced photomorphogenesis in dark-grown seedlings. A previous report showed that far red (FR) reduces plant sensitivity to JA. In the present study however FR did not suppress JA-induced growth response, gene expression, and defence against a pathogen.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.554324  DOI: Not available
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