Populus tremula (European aspen) shows no evidence of sexual dimorphism

Abstract

BackgroundEvolutionary theory suggests that males and females may evolve sexually dimorphic phenotypic and biochemical traits concordant with each sex having different optimal strategies of resource investment to maximise reproductive success and fitness. Such sexual dimorphism would result in sex biased gene expression patterns in non-floral organs for autosomal genes associated with the control and development of such phenotypic traits.ResultsWe examined morphological, biochemical and herbivory traits to test for sexually dimorphic resource allocation strategies within collections of sexually mature and immature Populus tremula (European aspen) trees. In addition we profiled gene expression in mature leaves of sexually mature wild trees using whole-genome oligonucleotide microarrays and RNA-Sequencing.ConclusionsWe found no evidence of sexual dimorphism or differential resource investment strategies between males and females in either sexually immature or mature trees. Similarly, single-gene differential expression and machine learning approaches revealed no evidence of large-scale sex biased gene expression. However, two significantly differentially expressed genes were identified from the RNA-Seq data, one of which is a robust diagnostic marker of sex in P. tremula.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-014-0276-5) contains supplementary material, which is available to authorized users.

Slow evolution of sex‐biased genes in the reproductive tissue of the dioecious plant Salix viminalis

“…Equivalent to studies on somatic and reproductive tissues in animal systems (Mank, ; Pointer et al., ; Yang et al, ), we found that the reproductive tissue was far more transcriptionally dimorphic than the vegetative tissue (Figures and ). Additionally, in plant species in particular, very few studies have been able to identify any significant sex‐biased genes in nonreproductive tissues (Robinson et al., ; Zemp, Minder, & Widmer, ; Zluvova et al., ). We also found that, in catkin, male‐biased genes were expressed at significantly higher levels and had a higher magnitude of sex‐bias than female‐biased genes (Figure ).…”

“…In contrast to animals, where sexual dimorphism is more frequent, only a small percentage (~5%) of flowering plants are dioecious (Renner, ; Robinson et al., ), where individuals have exclusively male or female reproductive organs. The majority (~90%) of angiosperms are hermaphroditic (Ainsworth, ; Barrett & Hough, ), where flowers are bisexual, while another small fraction are monoecious, where separate flowers within the same plant carry different reproductive organs (Renner, ).…”

“…Extensive studies in plants and animals have shown that genes with sex‐biased expression vary in abundance across different developmental stages and tissues (Grath & Parsch, ; Perry, Harrison, & Mank, ; Robinson et al., ; Zemp et al., ; Zluvova, Zak, Janousek, & Vyskot, ). Evolutionary dynamics analyses also indicate that different evolutionary pressures impact the rate of sequence evolution of sex‐biased genes; for example, sex‐biased genes in reproductive tissues tend to have different rates of protein evolution compared to unbiased genes (Dean et al., ; Lipinska et al., ; Mank, Nam, Brunström, & Ellegren, ; Perry et al., ; Sharma et al., ).…”

Araucaria Clonal Forestry: Types of Cuttings and Mother Tree Sex in Field Survival and Growth

“…A consequence of these adaptations could be the appearance of a phenotypic, biochemical, and ecological dimorphism, resulted from the resource allocation specifi ed for each sex, creating a state of great application depending on the specifi c needs of each sex (ROBINSON et al, 2014). Height and diameter have been the phenotypic characteristics most used as indicators to analyze these changes related to sex, considering that the vegetative vigor is the result of a larger adaptive capacity (DUDLEY, 2006;PETZOLD et al, 2012).…”

INDIRECT AND EXPEDITE ASSESSMENT OF Ilex paraguariensis COMMERCIAL YIELD

“…However, it is possible to perceive that the estimates of commercial biomass for male plants tended to be similar to the measured commercial biomass when compared to those of the female sex. This difference between sexes has been common in dioecious forestry species, and has been explained by the biological, biochemistry and phenotypic variation between sexes, resulting from the allocation of specific resources to supply each sex demands (ROBINSON et al, 2014;RAKOCEVIC et al, 2007;2009).…”