Endopolyploidy is associated with leaf functional traits and climate variation in Arabidopsis thaliana

Abstract

PremiseEndopolyploidy is widespread throughout the tree of life and is especially prevalent in herbaceous angiosperms. Its prevalence in this clade suggests that endopolyploidy may be adaptive, but its functional roles are poorly understood. To address this gap in knowledge, we explored whether endopolyploidy was associated with climatic factors and correlated with phenotypic traits related to growth.MethodsWe sampled stem and leaf endopolyploidy in 56 geographically separated accessions of Arabidopsis thaliana grown in a common garden to explore species variation and to determine whether this variation was correlated with climatic variables and other plant traits.ResultsStem endopolyploidy was not associated with climate or other traits. However, leaf endopolyploidy was significantly higher in accessions from drier and colder environments. Moreover, leaf endopolyploidy was positively correlated with apparent chlorophyll content and leaf dry mass.ConclusionsEndopolyploidy may have a functional role in the storage of chloroplasts and starch, and it may offer an adaptive avenue of tissue growth in cold and dry environments.

Ploidy and local environment drive intraspecific variation in endoreduplication in Arabidopsis arenosa

“…Contrary to our expectation, our study indeed revealed differences in endoreduplication between our pairs of foothill vs. alpine ecotypes, but the effect was not consistent across all pairs and exhibited rather regional‐ and treatment‐specific patterns. Our results are in line with other studies of A. thaliana where no clear association was found between endoreduplication and major environmental clines such as latitude (Gegas et al, 2014; Pacey et al, 2020a) and point to population‐specific patterns. Hence, despite an effect of single environmental factors on endoreduplication (i.e., UV‐B radiation), constitutive differences driven by environmental clines were generally weak, and the regional‐ or population‐specific patterns observed may also reflect a contribution of the local environment (and may involve different sets of genes) and/or of the lineage‐specific genetic background.…”

“…Our analyses thus informed on the endoreduplication level at a specific time of the elongation phase of the leaf of young A. arenosa plant. Because endoreduplication is correlated with the size of the leaf at the time of sampling (Pacey et al, 2020a), prior to analysis, we approximated the area of the selected leaf by multiplying leaf length by leaf width. Plants were processed generally following the same procedure as described by Kolář et al (2016).…”

“…To date, most of the studies have focused on the effects of a single environmental factor on endoreduplication, but only a few studies investigated variations in endoreduplication across the native range of a species. Common garden studies of A. thaliana showed constitutive variation in endoreduplication level between populations or accessions, but no clear associations with climatic factors, except for mean temperature or UV‐B radiation (Gegas et al, 2014; Scholes et al, 2017; Pacey et al, 2020a). Here, using a similar common garden approach, we investigated intraspecific variation in endoreduplication at a finer scale, along an elevational gradient.…”

Polyploid plants take cytonuclear perturbations in stride

“…In addition, development of vegetative tissues often involves rounds of DNA replications without cell division, resulting in large increases in nuclear ploidy (known as endoreduplication or endopolyploidy). Therefore, even more so than other eukaryotic lineages, plants may have evolved regulatory responses that coordinate mitochondrial and plastid function with changes in nuclear ploidy and cell size (Kawade et al, 2013;Pacey et al, 2020;He et al, 2021).…”