Autopolyploidy differentially influences body size in plants, but facilitates enhanced accumulation of secondary metabolites, causing increased cytosine methylation

• Published in: The Plant journal : for cell and molecular biology 2012-08, Vol.71 (4), p.539-549
• Main Authors: Lavania, Umesh C, Srivastava, Sarita, Lavania, Seshu, Basu, Surochita, Misra, Nandeesh Kumar, Mukai, Yasuhiko
• Format: Article
• Language: English
• Subjects: 5-Methylcytosine - metabolism; Aromatics; Autopolyploidy; Autotetraploid; Biological and medical sciences; Biomass; Body size; Cell size; Chemical composition; citral; clones; Cymbopogon; Cymbopogon - anatomy & histology; Cymbopogon - genetics; Cymbopogon - metabolism; Cytosine; Cytosine - metabolism; Diploids; Diploidy; DNA Methylation; DNA, Plant - metabolism; epigenetics; Essential oils; Evolution; Fundamental and applied biological sciences. Psychology; genome; Genome, Plant; Genomes; Geraniol; Grasses; in situ cytosine methylation; Metabolites; Methylation; Monoterpenes; Oils, Volatile - chemistry; Oils, Volatile - metabolism; Plant growth; Plant physiology and development; Plants - anatomy & histology; Plants - genetics; Ploidies; Ploidy; Polyploidy; polyploidy and body size; polyploidy and secondary metabolism; polyploidy breeding; Secondary metabolites; Stem cells; Tetraploidy; vigor
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/j.1365-313X.2012.05006.x

Whole genome duplication leads to autopolyploidy and brings about an increase in cell size, concentration of secondary metabolites and enhanced cytosine methylation. The increased cell size offers a positive advantage to polyploids for cell‐surface‐related activities, but there is a differential response to change in body size across species and taxonomic groups. Although polyploidy has been very extensively studied, having genetic, ecological and evolutionary implications, there is no report that underscores the significance of native secondary metabolites vis‐à‐vis body size with ploidy change. To address this problem we targeted unique diploid–autotetraploid paired sets of eight diverse clones of six species of Cymbopogon– a species complex of aromatic grasses that accumulate qualitatively different monoterpene essential oils (secondary metabolite) in their vegetative biomass. Based on the qualitative composition of essential oils and the plant body size relationship between the diploid versus autotetraploid paired sets, we show that polyploidy brings about enhanced accumulation of secondary metabolites in all cases, but exerts differential effects on body size in various species. It is observed that the accumulation of alcohol‐type metabolites (e.g. geraniol) does not inhibit increase in body size with ploidy change from 2× to 4× (r = 0.854, P