RNAi-Mediated Knockdown of Calreticulin3a Impairs Pollen Tube Growth in <i>Petunia</i>

Pollen tube growth depends on several complex processes, including exo/endocytosis, cell wall biogenesis, intracellular transport, and cell signaling. Our previous results provided evidence that calreticulin (CRT)—a prominent calcium (Ca<sup>2+</sup>)-buffering molecular chaperone in the...

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Main Authors: Piotr Wasąg, Anna Suwińska, Marta Lenartowska, Robert Lenartowski
Format: Article
Language:English
Published: MDPI AG 2022-04-01
Series:International Journal of Molecular Sciences
Subjects:
Online Access:https://www.mdpi.com/1422-0067/23/9/4987
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author Piotr Wasąg
Anna Suwińska
Marta Lenartowska
Robert Lenartowski
author_facet Piotr Wasąg
Anna Suwińska
Marta Lenartowska
Robert Lenartowski
author_sort Piotr Wasąg
collection DOAJ
description Pollen tube growth depends on several complex processes, including exo/endocytosis, cell wall biogenesis, intracellular transport, and cell signaling. Our previous results provided evidence that calreticulin (CRT)—a prominent calcium (Ca<sup>2+</sup>)-buffering molecular chaperone in the endoplasmic reticulum (ER) lumen—is involved in pollen tube formation and function. We previously cloned and characterized the <i>CRT</i> gene belonging to the <i>CRT1/</i>2 subgroup from <i>Petunia hybrida</i> (<i>PhCRT1/2</i>), and found that post-transcriptional silencing of <i>PhCRT1/2</i> expression strongly impaired pollen tube growth in vitro. Here, we report cloning of a new <i>PhCRT3a</i> homolog; we identified the full-length cDNA sequence and described its molecular characteristics and phylogenetic relationships to other plant <i>CRT3</i> genes. Using an RNA interference (RNAi) strategy, we found that knockdown of <i>PhCRT3a</i> gene expression caused numerous defects in the morphology and ultrastructure of cultivated pollen tubes, including disorganization of the actin cytoskeleton and loss of cytoplasmic zonation. Elongation of si<i>PhCRT3a</i> pollen tubes was disrupted, and some of them ruptured. Our present data provide the first evidence that <i>PhCRT3a</i> expression is required for normal pollen tube growth. Thus, we discuss relationships between diverse CRT isoforms in several interdependent processes driving the apical growth of the pollen tube, including actomyosin-dependent cytoplasmic streaming, organelle positioning, vesicle trafficking, and cell wall biogenesis.
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spelling doaj.art-e6e1bcb6ec514db3ba75c9afdd43c2552023-11-23T08:25:18ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672022-04-01239498710.3390/ijms23094987RNAi-Mediated Knockdown of Calreticulin3a Impairs Pollen Tube Growth in <i>Petunia</i>Piotr Wasąg0Anna Suwińska1Marta Lenartowska2Robert Lenartowski3Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, 87-100 Torun, PolandDepartment of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, 87-100 Torun, PolandDepartment of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, 87-100 Torun, PolandDepartment of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Torun, 87-100 Torun, PolandPollen tube growth depends on several complex processes, including exo/endocytosis, cell wall biogenesis, intracellular transport, and cell signaling. Our previous results provided evidence that calreticulin (CRT)—a prominent calcium (Ca<sup>2+</sup>)-buffering molecular chaperone in the endoplasmic reticulum (ER) lumen—is involved in pollen tube formation and function. We previously cloned and characterized the <i>CRT</i> gene belonging to the <i>CRT1/</i>2 subgroup from <i>Petunia hybrida</i> (<i>PhCRT1/2</i>), and found that post-transcriptional silencing of <i>PhCRT1/2</i> expression strongly impaired pollen tube growth in vitro. Here, we report cloning of a new <i>PhCRT3a</i> homolog; we identified the full-length cDNA sequence and described its molecular characteristics and phylogenetic relationships to other plant <i>CRT3</i> genes. Using an RNA interference (RNAi) strategy, we found that knockdown of <i>PhCRT3a</i> gene expression caused numerous defects in the morphology and ultrastructure of cultivated pollen tubes, including disorganization of the actin cytoskeleton and loss of cytoplasmic zonation. Elongation of si<i>PhCRT3a</i> pollen tubes was disrupted, and some of them ruptured. Our present data provide the first evidence that <i>PhCRT3a</i> expression is required for normal pollen tube growth. Thus, we discuss relationships between diverse CRT isoforms in several interdependent processes driving the apical growth of the pollen tube, including actomyosin-dependent cytoplasmic streaming, organelle positioning, vesicle trafficking, and cell wall biogenesis.https://www.mdpi.com/1422-0067/23/9/4987calreticulinmolecular cloningphylogenetic analysissiRNApollen tubeactin cytoskeleton
spellingShingle Piotr Wasąg
Anna Suwińska
Marta Lenartowska
Robert Lenartowski
RNAi-Mediated Knockdown of Calreticulin3a Impairs Pollen Tube Growth in <i>Petunia</i>
International Journal of Molecular Sciences
calreticulin
molecular cloning
phylogenetic analysis
siRNA
pollen tube
actin cytoskeleton
title RNAi-Mediated Knockdown of Calreticulin3a Impairs Pollen Tube Growth in <i>Petunia</i>
title_full RNAi-Mediated Knockdown of Calreticulin3a Impairs Pollen Tube Growth in <i>Petunia</i>
title_fullStr RNAi-Mediated Knockdown of Calreticulin3a Impairs Pollen Tube Growth in <i>Petunia</i>
title_full_unstemmed RNAi-Mediated Knockdown of Calreticulin3a Impairs Pollen Tube Growth in <i>Petunia</i>
title_short RNAi-Mediated Knockdown of Calreticulin3a Impairs Pollen Tube Growth in <i>Petunia</i>
title_sort rnai mediated knockdown of calreticulin3a impairs pollen tube growth in i petunia i
topic calreticulin
molecular cloning
phylogenetic analysis
siRNA
pollen tube
actin cytoskeleton
url https://www.mdpi.com/1422-0067/23/9/4987
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