Editing Erysimum (section)

== Ecology ==
''Erysimum'' is found in a range of habitats across the northern hemisphere, and has developed diverse morphology and growth habits (herbaceous annual or perennial, and woody perennial). Different ''Erysimum'' species are used as food plants by the [[larva]]e of some [[Lepidoptera]] ([[butterflies]] and [[moth]]s) species including the [[garden carpet]] (''Xanthorhoe fluctuata''). In addition, some species of weevils, like ''[[Ceutorhynchus chlorophanus]]'', live inside the fruits feeding on the developing seeds. Many species of beetles, bugs and grasshoppers eat the leaves and stalks. Some [[mammal]]ian herbivores, for example mule deer (''[[Odocoileus hemionus]]'') in North America, argali (''[[Ovis ammon]]'') in Mongolia, red deer (''[[Cervus elaphus]]'') in Central Europe, or Spanish ibex (''[[Capra pyrenaica]]'') in the Iberian Peninsula, feed on wallflower flowering and fruiting stalks. ''[[Erysimum crepidifolium]]'' (pale wallflower) is toxic to some generalist vertebrate herbivores.<ref name=":2">{{Cite book|title=Giftpflanzen, Pflanzengifte : Giftpflanzen von A-Z : Notfallhilfe : Vorkommen, Wirkung, Therapie : allergische und phototoxische Reaktionen|last=Roth, Lutz.|date=1994|publisher=Ecomed|isbn=3609648104|oclc=891791701}}</ref><ref name="Giftpflanzen.com">[http://www.giftpflanzen.com/erysimum_crepidifolium.html Bleicher Schöterich (''Erysimum crepidifolium''). In: giftpflanzen.com.]</ref>

Most wallflowers are pollinator-generalists, their flowers being visited by many different species of bees, bee flies, hoverflies, butterflies, beetles, and ants. However, there are some specialist species. For example, ''[[Erysimum scoparium]]'' is pollinated almost exclusively by ''[[Anthophora]] alluadii''.

===Defensive compounds===
Like most [[Brassicaceae]], species in the genus ''Erysimum'' produce [[glucosinolates]] as defensive compounds.<ref>{{cite journal |last1=Fahey |first1=Jed W. |last2=Zalcmann |first2=Amy T. |last3=Talalay |first3=Paul |title=The chemical diversity and distribution of glucosinolates and isothiocyanates among plants |journal=Phytochemistry |date=2001 |volume=56 |issue=1 |pages=5–51|doi=10.1016/S0031-9422(00)00316-2 |pmid=11198818 |bibcode=2001PChem..56....5F }}</ref><ref>{{Cite journal|last1=Züst|first1=Tobias|last2=Strickler|first2=Susan R|last3=Powell|first3=Adrian F|last4=Mabry|first4=Makenzie E|last5=An|first5=Hong|last6=Mirzaei|first6=Mahdieh|last7=York|first7=Thomas|last8=Holland|first8=Cynthia K|last9=Kumar|first9=Pavan|last10=Erb|first10=Matthias|last11=Petschenka|first11=Georg|last12=Gómez|first12=José-María|last13=Perfectti|first13=Francsco|last14=Müller|first14=Caroline|last15=Pires|first15=J Chris|last16=Mueller|first16=Lukas|last17=Jander|first17=Georg|date=2020-04-07|title=Independent evolution of ancestral and novel defenses in a genus of toxic plants (Erysimum, Brassicaceae)|journal=eLife|language=en|volume=9|pages=e51712|doi=10.7554/eLife.51712|issn=2050-084X|pmc=7180059|pmid=32252891 |doi-access=free }}</ref> However, unlike almost all other genera in the Brassicaceae, ''Erysimum'' also accumulates [[cardiac glycosides]], another class of [[phytochemicals]] with an ecological importance in insect defense.<ref>{{Cite journal|last1=Züst|first1=Tobias|last2=Mirzaei|first2=Mahdieh|last3=Jander|first3=Georg|date=2018-03-20|title=Erysimum cheiranthoides, an ecological research system with potential as a genetic and genomic model for studying cardiac glycoside biosynthesis|journal=Phytochemistry Reviews|volume=17|issue=6|pages=1239–1251|doi=10.1007/s11101-018-9562-4|bibcode=2018PChRv..17.1239Z |s2cid=53857970|issn=1568-7767|url=https://boris.unibe.ch/114835/ }}</ref><ref name=":0" />  Cardiac glycosides specifically function to prevent insect [[Herbivore|herbivory]]<ref>{{cite journal |last1=Dussourd |first1=DE |last2=Hoyle |first2=AM |title=Poisoned plusiines: toxicity of milkweed latex and cardenolides to some generalist caterpillars |journal=Chemical Ecology |date=2000 |volume=10|issue=1 |page=11 |doi=10.1007/PL00001810 |bibcode=2000Chmec..10...11D }}</ref> and/or [[Ovipositor|oviposition]]<ref>{{cite journal |last1=Renwick |first1=J. A. A. |last2=Radke |first2=C. D. |last3=Sachdev-Gupta |first3=K. |title=Chemical Constituents of ''Erysimum cheiranthoides'' Deterring Oviposition by the Cabbage Butterfly, ''Pieris rapae'' |journal=Journal of Chemical Ecology |date=1989 |volume=15 |issue=8|pages=2161–9 |doi=10.1007/BF01014106 |pmid=24272377 |bibcode=1989JCEco..15.2161R |s2cid=20866270 }}</ref> by blocking [[ion channel]] function in muscle cells.<ref>{{cite journal |last1=Paula |first1=S |last2=Tabet |first2=MR |last3=Ball |first3=WJ |title=Interactions between cardiac glycosides and sodium ⁄ potassium-ATPase: three-dimensional structure)activity relationship models for ligand binding to the E2-Pi form of the enzyme versus activity inhibition |journal=Biochemistry |date=2005 |volume=44|issue=2 |pages=498–510 |doi=10.1021/bi048680w |pmid=15641774 |url=https://figshare.com/articles/journal_contribution/3304402 }}</ref>  These chemicals are toxic enough to deter generalist,<ref>{{cite journal |last1=Karowe |first1=DN |last2=Golston |first2=V |title=Effect of the cardenolide digitoxin on performance of gypsy moth (''Lymantria dispar'') (Lepidoptera: Lymantriidae) caterpillars |journal=The Great Lakes Entomologist |date=2006 |volume=39}}</ref> and even some specialist<ref>{{cite journal |last1=Rassman |first1=s |last2=Johnson |first2=MD |last3=Agrawal |first3=AA |title=Induced responses to herbivory and jasmonate in three milkweed species |journal=Journal of Chemical Ecology |date=2009 |volume=35|issue=11 |page=1326 |doi=10.1007/s10886-009-9719-0 |bibcode=2009JCEco..35.1326R }}</ref> insect herbivores. [[Cardiac glycoside]] production is widespread in ''Erysimum'', with at least 48 species in the genus containing these compounds.<ref name=":0">{{cite journal |last1=Makarevich |first1=FI |last2=Zhernoklev |first2=KV |last3=Slyusarskaya |first3=TB |title=Cardenolide-containing plants of the family Cruciferae |journal=Chemistry of Natural Compounds |date=1994 |volume=30 |issue=3|pages=275–289 |doi=10.1007/BF00629957 |bibcode=1994CNatC..30..275M |s2cid=13763922 }}</ref><ref name=":8">{{Cite journal|last1=Züst|first1=Tobias|last2=Strickler|first2=Susan R.|last3=Powell|first3=Adrian F.|last4=Mabry|first4=Makenzie E.|last5=An|first5=Hong|last6=Mirzaei|first6=Mahdieh|last7=York|first7=Thomas|last8=Holland|first8=Cynthia K.|last9=Kumar|first9=Pavan|date=2019-09-08|title=Rapid and independent evolution of ancestral and novel defenses in a genus of toxic plants (Brassicaceae)|journal=bioRxiv|doi=10.1101/761569|doi-access=free}}</ref> Accumulation of cardiac glycosides in ''[[Erysimum crepidifolium]]'', but not other tested species, is induced by treatment with [[jasmonic acid]] and [[methyl jasmonate]],<ref>{{Cite journal|last1=Munkert|first1=Jennifer|last2=Ernst|first2=Mona|last3=Müller-Uri|first3=Frieder|last4=Kreis|first4=Wolfgang|date=2014|title=Identification and stress-induced expression of three 3β-hydroxysteroid dehydrogenases from Erysimum crepidifolium Rchb. and their putative role in cardenolide biosynthesis|journal=Phytochemistry|volume=100|pages=26–33|doi=10.1016/j.phytochem.2014.01.006|pmid=24512841|bibcode=2014PChem.100...26M |issn=0031-9422}}</ref><ref name=":8" /> endogenous elicitors of chemical defenses in many plant species.<ref>{{Cite journal|last1=Howe|first1=Gregg A.|last2=Jander|first2=Georg|date=2008|title=Plant Immunity to Insect Herbivores|journal=Annual Review of Plant Biology|volume=59|issue=1|pages=41–66|doi=10.1146/annurev.arplant.59.032607.092825|pmid=18031220|bibcode=2008AnRPB..59...41H |issn=1543-5008}}</ref>   Molecular [[phylogenetic]] analysis indicates that ''Erysimum'' diversification from other [[Brassicaceae]] species that do not produce cardiac glycosides began in the [[Pliocene]] (2.33–5.2 million years ago),<ref>{{cite journal |last1=Huang |first1=Chien-Hsun |last2=Sun |first2=Renran |last3=Hu |first3=Yi |last4=Zeng |first4=Liping |last5=Zhang |first5=Ning |last6=Cai |first6=Liming |last7=Zhang |first7=Qiang |last8=Koch |first8=Marcus A. |last9=Al-Shehbaz |first9=Ihsan |last10=Edger |first10=Patrick P. |last11=Pires |first11=J. Chris |last12=Tan |first12=Dun-Yan |last13=Zhong |first13=Yang |last14=Ma |first14=Hong |title=Resolution of Brassicaceae Phylogeny Using Nuclear Genes Uncovers Nested Radiations and Supports Convergent Morphological Evolution |journal=Molecular Biology and Evolution |date=2015 |volume=33 |issue=2|pages=394–412 |pmc=4866547 |pmid=26516094 |doi=10.1093/molbev/msv226 }}</ref><ref name=":1">{{cite journal |last1=Moazzeni |first1=Hamid |last2=Zarre |first2=Shahin |last3=Pfeil |first3=Bernard E. |last4=Bertrand |first4=Yann J. K. |last5=German |first5=Dmitry A. |last6=Al-Shebaz |first6=Ihsan A. |last7=Mummenhoff |first7=Klaus |last8=Oxelman |first8=Bengt |title=Phylogenetic perspectives on diversification and character evolution in the species-rich genus Erysimum (Erysimeae; Brassicaceae) based on a densely sampled ITS approach |journal=Botanical Journal of the Linnean Society |date=2014 |volume=175 |issue=4 |pages=497–522|doi=10.1111/boj.12184 |s2cid=82972738 |doi-access= }}</ref> suggesting relatively recent evolution of cardiac glycosides as a defensive trait in this genus.

=== Escape from herbivory ===
The evolution of novel chemical defenses in plants, such as [[cardenolide]]s in the genus ''Erysimum'', is predicted to allow escape from herbivory by specialist herbivores and expansion into new ecological niches.<ref>{{Cite journal|last1=Weber|first1=Marjorie G.|last2=Agrawal|first2=Anurag A.|date=2014|title=Defense mutualisms enhance plant diversification|journal=Proceedings of the National Academy of Sciences|volume=111|issue=46|pages=16442–16447|doi=10.1073/pnas.1413253111|pmid=25349406|issn=0027-8424|pmc=4246327|bibcode=2014PNAS..11116442W|doi-access=free}}</ref> The crucifer-feeding specialist ''[[Pieris rapae|Pieries rapae]]'' (white cabbage butterfly) is deterred from feeding and oviposition by cardenolides in ''[[Erysimum cheiranthoides]].''<ref>{{Cite journal|last=Feeny|first=Paul|date=1977|title=Defensive Ecology of the Cruciferae|journal=Annals of the Missouri Botanical Garden|volume=64|issue=2|pages=221–234|doi=10.2307/2395334|jstor=2395334|bibcode=1977AnMBG..64..221F |url=https://www.biodiversitylibrary.org/part/40250}}</ref><ref>{{Cite journal|last1=Renwick|first1=J. A. A.|last2=Radke|first2=Celia D.|date=1987|title=Chemical stimulants and deterrents regulating acceptance or rejection of crucifers by cabbage butterflies|journal=Journal of Chemical Ecology|volume=13|issue=7|pages=1771–1776|doi=10.1007/bf00980217|pmid=24302344|bibcode=1987JCEco..13.1771R |s2cid=24473740|issn=0098-0331}}</ref><ref>{{Cite journal|last1=Renwick|first1=J. A. A.|last2=Radke|first2=Celia D.|date=1985|title=Constituents of host- and non-host plants deterring oviposition by the cabbage butterfly, Pieris rapae|journal=Entomologia Experimentalis et Applicata|volume=39|issue=1|pages=21–26|doi=10.1111/j.1570-7458.1985.tb03538.x|bibcode=1985EEApp..39...21R |s2cid=86713452|issn=0013-8703}}</ref><ref>{{Cite journal|last1=Dimock|first1=M. B.|last2=Renwick|first2=J. A. A.|last3=Radke|first3=C. D.|last4=Sachdev-gupta|first4=K.|date=1991|title=Chemical constituents of an unacceptable crucifer,Erysimum cheiranthoides, deter feeding byPieris rapae|journal=Journal of Chemical Ecology|volume=17|issue=3|pages=525–533|doi=10.1007/bf00982123|pmid=24258803|bibcode=1991JCEco..17..525D |s2cid=32639023|issn=0098-0331}}</ref><ref>{{Cite journal|last1=Sachdev-Gupta|first1=K.|last2=Radke|first2=Cd.|last3=Renwick|first3=J. A. A.|last4=Dimock|first4=M. B.|date=1993|title=Cardenolides from Erysimum cheiranthoides: Feeding deterrents toPieris rapae larvae|journal=Journal of Chemical Ecology|volume=19|issue=7|pages=1355–1369|doi=10.1007/bf00984881|pmid=24249167|bibcode=1993JCEco..19.1355S |s2cid=258932|issn=0098-0331}}</ref> Similarly, ''Anthocharis cardamines'' (orange tip butterfly), which oviposits on almost all crucifer species, avoids ''[[Erysimum cheiranthoides|E. cheiranthoides]].''<ref>{{Cite journal|last1=Wiklund|first1=Christer|last2=Åhrberg|first2=Carl|last3=Ahrberg|first3=Carl|date=1978|title=Host Plants, Nectar Source Plants, and Habitat Selection of Males and Females of Anthocharis cardamines (Lepidoptera)|journal=Oikos|volume=31|issue=2|pages=169|doi=10.2307/3543560|issn=0030-1299|jstor=3543560|bibcode=1978Oikos..31..169W }}</ref> ''Erysimum asperum'' (western wallflower) is resistant to feeding and oviposition of ''Pieris napi macdunnoughii'' (synonym ''[[Pieris marginalis]]'', margined white butterfly).<ref>{{Cite journal|last=Chew|first=Frances S.|date=1975|title=Coevolution of pierid butterflies and their cruciferous foodplants|journal=Oecologia|volume=20|issue=2|pages=117–127|doi=10.1007/bf00369024|pmid=28308818|issn=0029-8549|bibcode=1975Oecol..20..117C|s2cid=29074343}}</ref><ref>{{Cite journal|last=Chew|first=Frances S.|date=1977|title=Coevolution of Pierid Butterflies and Their Cruciferous Foodplants. II. The Distribution of Eggs on Potential Foodplants|journal=Evolution|volume=31|issue=3|pages=568–579|doi=10.2307/2407522|issn=0014-3820|jstor=2407522|pmid=28563490}}</ref> Two crucifer-feeding beetles, ''Phaedon'' sp. and ''[[Phyllotreta]]'' sp., were deterred from feeding by [[cardenolide]]s that were applied to their preferred food plants.<ref>{{Cite journal|last=NIELSEN|first=JENS KVIST|date=1978|journal=Entomologia Experimentalis et Applicata|volume=24|issue=1|pages=41–54|doi=10.1111/j.1570-7458.1978.tb02755.x|issn=0013-8703|title=Host Plant Discrimination within Cruciferae: Feeding Responses of Four Leaf Beetles (Coleoptera: Chrysomelidae) to Glucosinolates, Cucurbitacins and Cardenolides|bibcode=1978EEApp..24...41N |s2cid=84602063}}</ref><ref>{{Cite journal|last=NIELSEN|first=J. K.|date=1978|journal=Entomologia Experimentalis et Applicata|volume=24|issue=3|pages=562–569|doi=10.1111/j.1570-7458.1978.tb02817.x|issn=0013-8703|title=Host Plant Selection of Monophagous and Oligophagous Flea Beetles Feeding on Crucifers|bibcode=1978EEApp..24..562N |s2cid=85648914}}</ref> Consistent with the hypothesis of enhanced speciation after escape from herbivory, phylogenetic studies involving 128 ''Erysimum'' species indicate diversification in Eurasia between 0.5 and 2 million years ago, and in North America between 0.7 and 1.65 million years ago.)<ref name=":1" /> This evolutionarily rapid expansion of the ''Erysimum'' genus has resulted in several hundred known species distributed throughout the northern hemisphere.<ref name=":1" /><ref name=":3" /><ref name=":4" /><ref name=":5" /><ref name=":6" /><ref name=":7" />