Analyses of Putative genes involved in the defense mechanism of Gracilaria changii in response to agarase and agarolytic bacteria treatments

Seaweed Gracilaria is the main source of agar worldwide. Information on the induced defense mechanisms of seaweed is scarce, particularly in the aspect of seaweed-microbe interactions. A set of differentially expressed genes from G.changii in response to agarase were generated from a previous study...

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Main Author: Lim, Ee Leen
Format: Thesis
Language:English
Published: 2014
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Online Access:http://psasir.upm.edu.my/id/eprint/52512/1/FBSB%202014%2029RR.pdf
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spelling my-upm-ir.525122017-05-19T04:30:35Z Analyses of Putative genes involved in the defense mechanism of Gracilaria changii in response to agarase and agarolytic bacteria treatments 2014-08 Lim, Ee Leen Seaweed Gracilaria is the main source of agar worldwide. Information on the induced defense mechanisms of seaweed is scarce, particularly in the aspect of seaweed-microbe interactions. A set of differentially expressed genes from G.changii in response to agarase were generated from a previous study through next generation sequencing of the seaweed transcriptomes. In this study, G. changii was treated with both agarase (which generates the microbe-induced molecular patterns) and a marine agarolytic bacteria, ABS1 isolated from degrading seaweed. The result from the previous study (agarase treatment) was verified and temporal gene expression of candidate genes at 1, 6 and 24 hours post-treatment (hpt) in response to both agarase and bacteria treatments was profiled by quantitative reversetranscription real-time PCR (qRT-PCR). A total of 20 out of 22 candidates verified have the same gene expression patterns as the next generation sequencing result,demonstrating a 90.9% positive correlation between the two analyses. Four candidates encoding plasma membrane calcium-transporting ATPase (GcPMCA),vanadium bromoperoxidase type 1 (GcVBPO1), 3-phosphoshikimate 1-carbpxyvinyltransferase (GcEPSP), and 12-oxophytodienoate reductase (GcOPR) showed more than 2-fold up-regulation compared to that of control samples upon agarase treatment, implying their importance in defense response. The gene encoding vanadium bromoperoxidase type 2 (GcVBPO2) showed more than 2-fold up-regulation compared to that of the control sample upon bacteria treatment. GcVBPO1 and GcVBPO2 displayed different expression profiles in response to the two treatments, indicating the existence of more than one signaling pathways in the transcriptional regulation of vanadium bromoperoxidase. The gene expression of 16 and 10 candidates were further profiled in agarase and bacteria treated samples at different time points, respectively. Most candidates were up-regulated at 1 hpt compared to that of the control sample at the same time point, indicating a rapid modulation of transcription in G. changii upon agarase treatment. The gene expression of these candidates displayed different expression profiles in bacteria treated samples. GcEPSP and GcVBPO2, were found to have the highest fold change when treated by agarase and agarolytic bacteria respectively, at 1 hpt. Temporal gene expression profile of candidates upon agarase and bacteria treatments in G. changii. Red algae Marine algae Gene expression - Research - Methodology 2014-08 Thesis http://psasir.upm.edu.my/id/eprint/52512/ http://psasir.upm.edu.my/id/eprint/52512/1/FBSB%202014%2029RR.pdf application/pdf en public masters Universiti Putra Malaysia Red algae Marine algae Gene expression - Research - Methodology
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
topic Red algae
Marine algae
Gene expression - Research - Methodology
spellingShingle Red algae
Marine algae
Gene expression - Research - Methodology
Lim, Ee Leen
Analyses of Putative genes involved in the defense mechanism of Gracilaria changii in response to agarase and agarolytic bacteria treatments
description Seaweed Gracilaria is the main source of agar worldwide. Information on the induced defense mechanisms of seaweed is scarce, particularly in the aspect of seaweed-microbe interactions. A set of differentially expressed genes from G.changii in response to agarase were generated from a previous study through next generation sequencing of the seaweed transcriptomes. In this study, G. changii was treated with both agarase (which generates the microbe-induced molecular patterns) and a marine agarolytic bacteria, ABS1 isolated from degrading seaweed. The result from the previous study (agarase treatment) was verified and temporal gene expression of candidate genes at 1, 6 and 24 hours post-treatment (hpt) in response to both agarase and bacteria treatments was profiled by quantitative reversetranscription real-time PCR (qRT-PCR). A total of 20 out of 22 candidates verified have the same gene expression patterns as the next generation sequencing result,demonstrating a 90.9% positive correlation between the two analyses. Four candidates encoding plasma membrane calcium-transporting ATPase (GcPMCA),vanadium bromoperoxidase type 1 (GcVBPO1), 3-phosphoshikimate 1-carbpxyvinyltransferase (GcEPSP), and 12-oxophytodienoate reductase (GcOPR) showed more than 2-fold up-regulation compared to that of control samples upon agarase treatment, implying their importance in defense response. The gene encoding vanadium bromoperoxidase type 2 (GcVBPO2) showed more than 2-fold up-regulation compared to that of the control sample upon bacteria treatment. GcVBPO1 and GcVBPO2 displayed different expression profiles in response to the two treatments, indicating the existence of more than one signaling pathways in the transcriptional regulation of vanadium bromoperoxidase. The gene expression of 16 and 10 candidates were further profiled in agarase and bacteria treated samples at different time points, respectively. Most candidates were up-regulated at 1 hpt compared to that of the control sample at the same time point, indicating a rapid modulation of transcription in G. changii upon agarase treatment. The gene expression of these candidates displayed different expression profiles in bacteria treated samples. GcEPSP and GcVBPO2, were found to have the highest fold change when treated by agarase and agarolytic bacteria respectively, at 1 hpt. Temporal gene expression profile of candidates upon agarase and bacteria treatments in G. changii.
format Thesis
qualification_level Master's degree
author Lim, Ee Leen
author_facet Lim, Ee Leen
author_sort Lim, Ee Leen
title Analyses of Putative genes involved in the defense mechanism of Gracilaria changii in response to agarase and agarolytic bacteria treatments
title_short Analyses of Putative genes involved in the defense mechanism of Gracilaria changii in response to agarase and agarolytic bacteria treatments
title_full Analyses of Putative genes involved in the defense mechanism of Gracilaria changii in response to agarase and agarolytic bacteria treatments
title_fullStr Analyses of Putative genes involved in the defense mechanism of Gracilaria changii in response to agarase and agarolytic bacteria treatments
title_full_unstemmed Analyses of Putative genes involved in the defense mechanism of Gracilaria changii in response to agarase and agarolytic bacteria treatments
title_sort analyses of putative genes involved in the defense mechanism of gracilaria changii in response to agarase and agarolytic bacteria treatments
granting_institution Universiti Putra Malaysia
publishDate 2014
url http://psasir.upm.edu.my/id/eprint/52512/1/FBSB%202014%2029RR.pdf
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