Characterizaion of the mechanism underlying auxin-induced seed arrest in Arabidopsis thaliana

In flowering plants, seeds are produced as a result of double fertilization, whereby the haploid egg cell and the diploid central cell fuse with one of the two haploid sperm cells giving rise to a diploid embryo and a triploid endosperm, respectively. The endosperm serves as the major nutrient sourc...

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Main Author: Venkatesan, Sowmiya Devi
Format: H2
Language:Inglés
Published: SLU/Dept. Of Plant Biology 2020
Subjects:
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author Venkatesan, Sowmiya Devi
author_browse Venkatesan, Sowmiya Devi
author_facet Venkatesan, Sowmiya Devi
author_sort Venkatesan, Sowmiya Devi
collection Epsilon Archive for Student Projects
description In flowering plants, seeds are produced as a result of double fertilization, whereby the haploid egg cell and the diploid central cell fuse with one of the two haploid sperm cells giving rise to a diploid embryo and a triploid endosperm, respectively. The endosperm serves as the major nutrient source for the developing embryo yet the molecular mechanisms pertaining to its development are not fully understood. Interploidy hybridizations cause improper endosperm development, establishing a reproductive barrier called the triploid block. Recent studies have linked the phytohormone auxin to the above process. Here, we show that an increase in auxin biosynthesis in the endosperm induced a seed abortion phenotype that resembles the phenotype of paternal-excess triploid seeds. Among the similarities, nrpd1, a mutant in RNA POLYMERASE IV, could impair the seed abortion phenotype induced by both triploid block and auxin over-expression, suggesting a vital role for the RNA silencing pathways in mediating the auxin and paternal genome dosage response. To test this link between RNA silencing and auxin-induced seed abortion, several loss-of-function mutants of the RNA silencing pathway have been assayed for their ability to affect the seed abortion phenotype induced by auxin overexpression. We found dcl3, a member of the RNA-directed DNA methylation (RdDM) pathway to have the same effect as nrpd1. Therefore, we propose that at least a part of the RdDM pathway is involved in the seed abortion phenotype induced by the auxin overexpression.
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institution Swedish University of Agricultural Sciences
language Inglés
publishDate 2020
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publisher SLU/Dept. Of Plant Biology
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spelling RepoSLU155952020-06-23T01:04:07Z Characterizaion of the mechanism underlying auxin-induced seed arrest in Arabidopsis thaliana Karaktärisering av mekanismen bakom auxin-inducerad utsädesarrestering i Arabidopsis thaliana Venkatesan, Sowmiya Devi endosperm hybridization barriers triploid block auxins RNA Polymerase IV RNA silencing In flowering plants, seeds are produced as a result of double fertilization, whereby the haploid egg cell and the diploid central cell fuse with one of the two haploid sperm cells giving rise to a diploid embryo and a triploid endosperm, respectively. The endosperm serves as the major nutrient source for the developing embryo yet the molecular mechanisms pertaining to its development are not fully understood. Interploidy hybridizations cause improper endosperm development, establishing a reproductive barrier called the triploid block. Recent studies have linked the phytohormone auxin to the above process. Here, we show that an increase in auxin biosynthesis in the endosperm induced a seed abortion phenotype that resembles the phenotype of paternal-excess triploid seeds. Among the similarities, nrpd1, a mutant in RNA POLYMERASE IV, could impair the seed abortion phenotype induced by both triploid block and auxin over-expression, suggesting a vital role for the RNA silencing pathways in mediating the auxin and paternal genome dosage response. To test this link between RNA silencing and auxin-induced seed abortion, several loss-of-function mutants of the RNA silencing pathway have been assayed for their ability to affect the seed abortion phenotype induced by auxin overexpression. We found dcl3, a member of the RNA-directed DNA methylation (RdDM) pathway to have the same effect as nrpd1. Therefore, we propose that at least a part of the RdDM pathway is involved in the seed abortion phenotype induced by the auxin overexpression. SLU/Dept. Of Plant Biology 2020 H2 eng https://stud.epsilon.slu.se/15595/
spellingShingle endosperm
hybridization barriers
triploid block
auxins
RNA Polymerase IV
RNA silencing
Venkatesan, Sowmiya Devi
Characterizaion of the mechanism underlying auxin-induced seed arrest in Arabidopsis thaliana
title Characterizaion of the mechanism underlying auxin-induced seed arrest in Arabidopsis thaliana
title_full Characterizaion of the mechanism underlying auxin-induced seed arrest in Arabidopsis thaliana
title_fullStr Characterizaion of the mechanism underlying auxin-induced seed arrest in Arabidopsis thaliana
title_full_unstemmed Characterizaion of the mechanism underlying auxin-induced seed arrest in Arabidopsis thaliana
title_short Characterizaion of the mechanism underlying auxin-induced seed arrest in Arabidopsis thaliana
title_sort characterizaion of the mechanism underlying auxin-induced seed arrest in arabidopsis thaliana
topic endosperm
hybridization barriers
triploid block
auxins
RNA Polymerase IV
RNA silencing