Cloning and characterisation of a putative pollen‐specific polygalacturonase gene (CpPG1) differentially regulated during pollen development in zucchini (Cucurbita pepo L.). (23rd July 2013)

• Record Type: Journal Article
• Authors: Carvajal, F.; Garrido, D.; Jamilena, M.; Rosales, R.; Elzenga, T.
• Is Part Of: Plant biology. Volume 16:Number 2(2014:Mar.)
• Page Start: 457
• Page End: 466
• Publication Date: 2013-07-23
• Subjects: Botany -- Periodicals; Plants -- genetics -- Periodicals; Plants -- growth & development -- Periodicals; Plant Proteins -- Periodicals; Gene Expression Regulation, Plant -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1111/plb.12070
• Languages: English
• ISSNs: 1435-8603

Abstract

<abstract abstract-type="main" id="plb12070-abs-0001"> <title>Abstract</title> <p>Studies in zucchini (<italic>Cucurbita pepo</italic> L. spp. <italic>pepo</italic>) pollen have been limited to the viability and morphology of the mature pollen grain. The enzyme polygalacturonase (PG) is involved in pollen development and pollination in many species. In this work, we study anther and pollen development of <italic>C. pepo</italic> and present the cloning and characterisation of a putative PG <italic>CpPG1</italic> (Accession no. <ext-link ext-link-type="gen" xlink:href="http://www.ncbi.nlm.nih.gov/nuccore/HQ232488?report=GenBank" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">HQ232488</ext-link>) from pollen cDNA in <italic>C. pepo</italic>. The predicted protein for <italic>CpPG1</italic> has 416 amino acids, with a high homology to other pollen PGs, such as P22 from <italic>Oenothera organensis</italic> (76%) and PGA3 from <italic>Arabidopsis thaliana</italic> (73%). CpPG1 belongs to clade C, which comprises PGs expressed in pollen, and presents a 34 amino acid signal peptide for secretion towards the cell wall. DNA‐blot analysis revealed that there are at least another two genes that code for PGs in <italic>C. pepo</italic>. The spatial and temporal accumulation of <italic>CpPG1</italic> was studied by semi‐quantitative‐ and qRT‐PCR. In addition, mRNA was detected only in anthers, pollen and the rudimentary anthers of bisexual flowers (only present in some zucchini cultivars under certain environmental conditions that trigger anther development in the third whorl of female flowers). However, no expression was detected in cotyledons, stem or fruit. Furthermore, <italic>CpPG1</italic> mRNA was accumulated throughout anther development, with the highest expression found in mature pollen. Similarly, <italic>exo‐</italic>PG activity increased from immature anther stages to mature anthers and mature pollen. Overall, these data support the pollen specificity of this gene and suggest an involvement of CpPG1 in pollen development in <italic>C. pepo</italic>.</p> </abstract>