When a Crop Goes Back to the Wild: Feralization

Feral plants have been known since the inception of modern agriculture, but genetic changes during what seemed to be a simple reversion domesticated form are poorly understood. Recent studies, revealing occurring in weedy rice, show an unexpected degree differentiation these feral escapes. Feralization (see Glossary) can considered, under many aspects, opposite domestication. During crop (and animal) domestication, wild forms gradually become adapted – regime artificial selection new environment where humans intervene control their growth and reproduction (e.g., agroecosystem). feralization, this process is reversed. Domesticated races escape human cultivation, return (or, any case, start propagate reproduce without intervention), revert phenotypes more typical forms. For example, invasive habitus some or aggressive behavior Australian dingoes. Thus, species from adapt environment, absence deliberate input, reassuming characteristics ancestral, truly wild, progenitors (atavism) [1.Gering E. et al.Getting back nature: feralization animals plants.Trends Ecol. Evol. 2019; 34: 1137-1151Abstract Full Text PDF PubMed Scopus (34) Google Scholar]. In cases, at certain stages life cycle, organisms may also mimic races, as case weeds resembling plants, so that they evade eradication by farmers [2.Ye C.Y. al.Genomic evidence on Vavilovian mimicry.Nat. 3: 1474-1482Crossref (20) Scholar].Although existence has inevitable nuisance origin agriculture animal husbandry, induced never investigated detail. Only recently few population genomics studies started illustrate animals, see [3.Zhang S.J. regions dingoes.Nat. Commun. 2020; 11: 671Crossref (27) Scholar]) undergo feralization. The emerging picture de-domestication accompanied multiple several loci, affecting morphology, growth, and, behavior, neurodevelopment, thus, presumably, hormone metabolism. Although recent revealed genomic differentiating progenitor accompanying opinion article Wu al. [4.Wu D. al.De-domestication: extension evolution.Trends Plant Sci. 2021; 26 (in press)https://doi.org/10.1016/j.tplants.2021.02.003Abstract (14) Scholar]), it not yet clear if, which extent, involved additional direct indirect plant metabolism its regulation.Invasive are, sometimes, examples populations. So far, only detailed analysis populations rice (Oryza sativa f. spontanea), frequently co-occurs competes paddy fields with cultivated significantly decreases quality grains given inevitably co-harvested together commercial cultivars. Weedy diffused all areas (America, Central South-eastern Asia, Europe) controlling diffusion always problematic: seeds shatter (while does not), remain dormant soil for years, when germinate, herbicides was found cause losses cultivars.Several whole-genome sequencing accessions, alongside phylogenetic proximity other forms, traced varieties cultivars were often grown same [5.Qiu J. al.Diverse mechanisms underlie worldwide convergent feralization.Genome Biol. 21: 70Crossref (28) general, diversity accessions lower than progenitors, exception province Guangdong China Latin America) local showed large hybrid ancestry. study ‘exoferal’ populations, characterized admixture between domestic, gene pools, provided regard possible transgenes herbicide resistance genetically manipulated varieties, although possibility de novo mutations conferring could excluded If we take global look distribution (the situation similar dogs chickens), exoferal coexist instead entirely derived progenitor, almost complete (endoferality).In scans widely used characterize carrying signatures differential weedy, domestic strains. This highlighted characteristic already apparent mammals [6.Johnsson M. al.Feralisation targets different loci domestication chicken.Nat. 2016; 7: 12950Crossref (30) Scholar], generally occur through alleles targeted is, major part, independent process. Most carry, allele sh4 (which determines, background, delayed shattering), effectively disperse maturity. shattering phenotype thus fixed [7.Li L.F. al.Signatures adaptation genome.Nat. Genet. 2017; 49: 811-814Crossref (98) Scholar].Genomic uncovered regions, shared de-domestication. One conserved blocks, japonica indica-type spanning around 0.5 Mbp chromosome 7, contained genes role environmental adaptation. Among Rc (red pericarp, bHLH transcription factor synthesis proanthocyanidins), RAL (a cluster six encoding seed allergenic proteins), LtpL (lipid transfer proteins). All functions protecting against pathogens, constitute adaptive traits maintenance germination capacity dormancy. Another block selected harbored GD1 (germination defective1), carbohydrate gibberellin [8.Guo X. al.The GERMINATION DEFECTIVE 1, B3 domain transcriptional repressor, regulates seedling development integrating GA metabolism.Plant 2013; 75: 403-416Crossref (52) two contrasting phenotypic effects clearly differentiated accessions. overall there suggesting related color, germination, stress underwent parallel evolution escapes domesticates toward weediness.Because genetics focused far weediness, difficult generalize findings apply cases evolved ancestors. appears target directly metabolic genes, mainly associated evolutionary regulatory way observed main syndrome [9.Purugganan M.D. Evolutionary insights into nature domestication.Curr. 29: R705-R714Abstract (107) marks difference respect mammal domestication), carbohydrate, fatty acid, had dingoes carnivorous descending dogs), digestion, (as adaptations diet), neurodevelopment (with probably sexual maturity behavioral changes; Figure 1). These ascribed de-domestication, remained isolated ancestral significant endoferality, Scholar]).These initial stimulate questions future investigations. However, our stand out priorities: (i) Does natural fixation standing variation newly emerged mutations? present pieces both cases. pre-existing shown potential rapidly fixed; indica however, mutations; (ii) processes metabolism? perhaps too early assess, knowledge currently limited rice. From know stress/disease resistance, dormancy color flowering time. represent reversals genes. vein, if involves regulation pathway(s), little common those Many escapes, increased competitive ability counterparts; trait achieved pathways allelopathy. pervasive, direct, undirect [10.Beleggia R. al.Evolutionary metabolomics reveals domestication-associated tetraploid wheat kernels.Mol. 33: 1740-1753Crossref (68) Scholar,11.Zhu G. al.Rewiring Fruit Metabolome Tomato Breeding.Cell. 2018; 172: 249-261.e12Abstract (379) anticipate restructuring will likely accompany plants.Declaration InterestsThere no interests declare. regulation. Invasive Several (endoferality). Genomic weediness. Because Scholar]). plants. Declaration There presence flow previously operated improve specific evolution, starting ancestors, mediated leading appearance agroecosystem. selection. emerges action homologous opposed convergence, indicates taxa). polymorphic sites existent population.