The influence of experimentally induced polyploidy on the relationships between endopolyploidy and plant function in Arabidopsis thaliana

Abstract

Whole genome duplication, leading to polyploidy and endopolyploidy, occurs in all domains and kingdoms and is especially prevalent in vascular plants. Both polyploidy and endopolyploidy increase cell size, but it is unclear whether both processes have similar effects on plant morphology and function, or whether polyploidy influences the magnitude of endopolyploidy. To address these gaps in knowledge, fifty-five geographically separated diploid accessions of Arabidopsis thaliana that span a gradient of endopolyploidy were experimentally manipulated to induce polyploidy. Both the diploids and artificially induced tetraploids were grown in a common greenhouse environment and evaluated with respect to nine reproductive and vegetative characteristics. Induced polyploidy decreased leaf endopolyploidy and stem endopolyploidy along with specific leaf area and stem height, but increased days to bolting, leaf size, leaf dry mass, and leaf water content. Phenotypic responses to induced polyploidy varied significantly among accessions but this did not affect the relationship between phenotypic traits and endopolyploidy. Our results provide experimental support for a trade-off between induced polyploidy and endopolyploidy, which caused induced polyploids to have lower endopolyploidy than diploids. Though polyploidy did not influence the relationship between endopolyploidy and plant traits, phenotypic responses to experimental genome duplication could not be easily predicted because of strong cytotype by accession interactions. K E Y W O R D SArabidopsis thaliana, colchicine, endopolyploidy, induced polyploidy, phenotype, polyploidy, trade-off, whole genome duplication | 199 PACEY Et Al.

Do Specialized Cells Play a Major Role in Organic Xenobiotic Detoxification in Higher Plants?

“…In this perspective, endoreduplication in basal salt gland cells could be related with enhanced xenobiotic storage/metabolization potentials (in addition to evolutionary benefits potentially raised by polyploidy), as proposed concerning Arabidopsis trichomes or pavement cells. To date, the relationship between inherited polyploidy and endopolyploidy is still unclear, but Pacey et al. (2020) provided recent evidences that polyploidy reduces endopolyploidy (by comparing Arabidopsis diploid vs. colchicine-treated tetraploid accessions).…”

“…In this perspective, endoreduplication in basal salt gland cells could be related with enhanced xenobiotic storage/metabolization potentials (in addition to evolutionary benefits potentially raised by polyploidy), as proposed concerning Arabidopsis trichomes or pavement cells. To date, the relationship between inherited polyploidy and endopolyploidy is still unclear, but Pacey et al (2020) provided recent evidences that polyploidy reduces endopolyploidy (by comparing Arabidopsis diploid vs. colchicine-treated tetraploid accessions). However, such trade-off was not currently reported between all Arabidopsis genotypes considered by Scholes (2020), depicting that endopolyploidy affected by inherited polyploidy is genotype dependent, and may also increase specifically in tetraploid plants in response to stress damage.…”

Nuclear-cytoplasmic balance: whole genome duplications induce elevated organellar genome copy number

“…It is possible that our data underestimated organellar genome copy numbers per cell if a significant fraction of the leaf cells have experienced endoreduplication. Species with large genomes, including polyploids, have been shown to undergo lower rates of endoreduplication (Barow and Meister, 2003; Pacey et al ., 2020). Therefore, the difference in the actual average amount of nuclear DNA per cell in diploids vs. polyploids may be lower than implied by their nominal ploidy levels, resulting in a form of immediate compensation in the polyploid species.…”

Spatial and Temporal Patterns of Endopolyploidy in Mosses

“…Alternatively, endopolyploidy may simply compensate for low DNA content in gametophytic (haploid) or sporophytic (diploid) tissues and help to promote growth and development through nucleotypic effects. Recent studies of endopolyploidy in diploid and isogenic polyploid angiosperms have revealed that diploids tend to show higher endopolyploidy than autopolyploids [ 41 , 67 ], possibly due to compensation for lower basic inherited organism-specific ploidy. These studies, however, conclude that this pattern is not general but genotype-specific.…”