Tetraketide α-pyrone reductases in sporopollenin synthesis pathway in Gerbera hybrida: diversification of the minor function
Open Access
- 1 October 2021
- journal article
- research article
- Published by Oxford University Press (OUP) in Horticulture Research
- Vol. 8 (1), 1-12
- https://doi.org/10.1038/s41438-021-00642-8
Abstract
The structurally robust biopolymer sporopollenin is the major constituent of the exine layer of pollen wall and plays a vital role in plant reproductive success. The sporopollenin precursors are synthesized through an ancient polyketide biosynthetic pathway consisting of a series of anther-specific enzymes that are widely present in all land plant lineages. Tetraketide α-pyrone reductase 1 (TKPR1) and TKPR2 are two reductases catalyzing the final reduction of the carbonyl group of the polyketide synthase-synthesized tetraketide intermediates to hydroxylated α-pyrone compounds, important precursors of sporopollenin. In contrast to the functional conservation of many sporopollenin biosynthesis associated genes confirmed in diverse plant species, TKPR2’s role has been addressed only in Arabidopsis, where it plays a minor role in sporopollenin biosynthesis. We identified in gerbera two non-anther-specific orthologues of AtTKPR2, Gerbera reductase 1 (GRED1) and GRED2. Their dramatically expanded expression pattern implies involvement in pathways outside of the sporopollenin pathway. In this study, we show that GRED1 and GRED2 are still involved in sporopollenin biosynthesis with a similar secondary role as AtTKPR2 in Arabidopsis. We further show that this secondary role does not relate to the promoter of the gene, AtTKPR2 cannot rescue pollen development in Arabidopsis even when controlled by the AtTKPR1 promoter. We also identified the gerbera orthologue of AtTKPR1, GTKPR1, and characterized its crucial role in gerbera pollen development. GTKPR1 is the predominant TKPR in gerbera pollen wall formation, in contrast to the minor roles GRED1 and GRED2. GTKPR1 is in fact an excellent target for engineering male-sterile gerbera cultivars in horticultural plant breeding.Keywords
Funding Information
- China Scholarship Council
- China Scholarship Council
This publication has 42 references indexed in Scilit:
- Evolutionary development of the plant spore and pollen wallAoB Plants, 2011
- Analysis of TETRAKETIDE α-PYRONE REDUCTASE Function in Arabidopsis thaliana Reveals a Previously Unknown, but Conserved, Biochemical Pathway in Sporopollenin Monomer BiosynthesisTHE PLANT CELL ONLINE, 2010
- LAP6/POLYKETIDE SYNTHASE AandLAP5/POLYKETIDE SYNTHASE BEncode Hydroxyalkyl α-Pyrone Synthases Required for Pollen Development and Sporopollenin Biosynthesis inArabidopsis thalianaTHE PLANT CELL ONLINE, 2010
- Characterization of SQUAMOSA-like genes in Gerbera hybrida, including one involved in reproductive transitionBMC Plant Biology, 2010
- Identification of genes differentially expressed during interaction of resistant and susceptible apple cultivars (Malus × domestica) with Erwinia amylovoraBMC Plant Biology, 2010
- CYP704B1 Is a Long-Chain Fatty Acidω-Hydroxylase Essential for Sporopollenin Synthesis in Pollen of ArabidopsisPlant Physiology, 2009
- A Novel Fatty Acyl-CoA Synthetase Is Required for Pollen Development and Sporopollenin Biosynthesis inArabidopsisTHE PLANT CELL ONLINE, 2009
- CYP703 Is an Ancient Cytochrome P450 in Land Plants Catalyzing in-Chain Hydroxylation of Lauric Acid to Provide Building Blocks for Sporopollenin Synthesis in PollenTHE PLANT CELL ONLINE, 2007
- Agrobacterium-mediated transformation of Arabidopsis thaliana using the floral dip methodNature Protocols, 2006
- A new mathematical model for relative quantification in real-time RT-PCRNucleic Acids Research, 2001