Ploidy in Plant Tolerance to Apical Meristem Damage: A Test of Relative Costs and Benefits

Premise of research. Polyploidy is known to affect many organismal attributes, including growth rates, life history, and environmental tolerance. Endopolyploidy, the condition of having an increased genome copy number relative to that inherited, allows many taxa to increase ploidy plastically and thus benefit from its effects in specific times and cell types. Endopolyploidy relates positively with plant damage tolerance, though the role of inherited ploidy in combination with endopolyploidy is unknown.Methodology. I grew three genotypes of Arabidopsis thaliana in diploid and tetraploid forms and applied a stem clipping treatment to half of the plants. Measures of endopolyploidy, growth, and fitness for each genotype × ploidy × clipping group were compared among the three-factor combinations. I also compared the response of a diploid cell cycle mutant with the responses of the diploid and tetraploid forms of its genetic progenitor.Pivotal results. Investment into undamaged growth and reproduction trades of...