Sub-Genome Polyploidization Effects on Metabolomic Signatures in Triploid Hybrids of Populus

Shiping Cheng,Xuewen Wang,Yuxia Zong

doi:10.3390/f10121091

Shiping Cheng, Xuewen Wang + Show 1 more

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https://doi.org/10.3390/f10121091

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Journal: Forests	Publication Date: Dec 1, 2019
Citations: 5	License type: CC BY 4.0

Affiliation: University of Georgia, Pingdingshan University

Abstract

Allopolyploids are known to have superior advantages such as high growth speed. Triploids have even greater heterozygosity, explaining more phenotypic variance than 2n hybrid F1 and have therefore become new resources in breeding. To date, the metabolomic basis underlying polyploidization vigor remains unclear. Here, we identified and compared 235 metabolites in the shoot apical buds between multiple allo-triploid populations and parental 2n hybrid F1 in Populus via metabolome profiling using liquid chromatography–mass spectrometry (LC–MS) assays. Associations with growth vigor in three types of allo-triploid populations, namely first division restitution (FDR), second division restitution (SDR) and postmeiotic restitution (PMR) generated from doubled 2n female gametes and male gametes of 2n hybrid, were also investigated. Each allo-triploid population has different sub-genome duplicated. Major metabolomes were amino acids, secondary metabolism associated, and carbohydrates. We mapped 181 metabolites into known metabolism pathways in the Kyoto Encyclopedia of Genes and Genomes (KEGG). Ten compounds, i.e., fructose 1,6-diphosphate and xylulose, were more abundant in all allo-triploids than the 2n hybrid. Principal component analysis revealed the abundance of metabolites fell into distinct clusters corresponding to ploidy composition. Heterozygosity in triploids mainly effected the contents of carbohydrates and secondary metabolites rather than lipids. Comparisons between subgroups with different growth rates revealed some carbohydrates and secondary metabolites of flavonoids were positively associated with gene expression and the high growth vigor. The results provided an informative metabolomic basis for factors conferring growth vigor in polyploid Populus.

Highlights

Polyploid organisms have more than two sets of chromosomes; 30–80% of plant kingdom are polyploid
Gene ontology (GO) terms expressed and Differentially expressed genes (DEGs) expressional regulation of genes on these flavonoids and gene ontology of thethe differentially were enriched in the biosynthesis and positive regulatory pathways of flavonoids, consistent with genes (DEGs) identified in previous RNA-Seq data [13]
Gene ontology (GO) was enriched for these DEGs involved in metabolisms of RNA-Seq analysis

Summary

Introduction

Polyploid organisms have more than two sets of chromosomes; 30–80% of plant kingdom are polyploid. Many plant lineages show evidence of palaeopolyploidization in their genomes. Polyploid plants usually have larger cell size and faster growth, which are both agronomically preferred traits [1]. Polyploid breeding in plants, including synthesized polyploidization, has increased the rate of breeding in many crops and in trees, such as Populus [2,3,4,5]. A reduction in genome size occurs after polyploidization, followed by neo-functionalization, sub-functionalization and gene product dosage balance, gene rearrangement, and epigenetic modification, which all drive the evolution and speciation [6]. Cell size is usually increased in polyploid plants likely due to a delayed cell division [5]

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