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Cloning and characterisation of a putative pollen‐specific polygalacturonase gene ( Cp PG 1 ) differentially regulated during pollen development in zucchini ( C ucurbita pepo L.)
Author(s) -
Carvajal F.,
Garrido D.,
Jamilena M.,
Rosales R.
Publication year - 2014
Publication title -
plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 1435-8603
DOI - 10.1111/plb.12070
Subject(s) - cucurbita pepo , pollen , biology , stamen , botany , pollination , gene , biochemistry
Studies in zucchini ( C ucurbita pepo L. spp. pepo ) 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 C . pepo and present the cloning and characterisation of a putative PG CpPG1 (Accession no. HQ232488 ) from pollen c DNA in C . pepo . The predicted protein for CpPG1 has 416 amino acids, with a high homology to other pollen PG s, such as P22 from O enothera organensis (76%) and PGA3 from A rabidopsis thaliana (73%). CpPG1 belongs to clade C, which comprises PG s 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 PG s in C . pepo . The spatial and temporal accumulation of CpPG1 was studied by semi‐quantitative‐ and q RT ‐ PCR . In addition, m RNA 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, CpPG1 m RNA was accumulated throughout anther development, with the highest expression found in mature pollen. Similarly, exo‐ 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 C . pepo .