Different outcomes for the MYB floral symmetry genes DIVARICATA and RADIALIS during the evolution of derived actinomorphy in Plantago. Issue 2 (27th January 2014)

• Record Type: Journal Article
• Authors: Reardon, Wesley; Gallagher, Pauline; Nolan, Katie M.; Wright, Hayley; Cardeñosa‐Rubio, Maria Cruz; Bragalini, Claudia; Lee, Chui‐Sang; Fitzpatrick, David A.; Corcoran, Killian; Wolff, Kirsten; Nugent, Jacqueline M.
• Is Part Of: New phytologist. Volume 202:Issue 2(2014)
• Page Start: 716
• Page End: 725
• Publication Date: 2014-01-27
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.12682
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph12682-abs-0001"> <title>Summary</title> <p> <list id="nph12682-list-0001" list-type="bullet"> <list-item> <p>The gene network that specifies flower shape in <italic>Antirrhinum majus</italic> (bilateral floral symmetry or zygomorphy) includes two MYB‐class genes – <italic>RADIALIS</italic> (<italic>RAD</italic>) and <italic>DIVARICATA</italic> (<italic>DIV</italic>). <italic>RAD</italic> is involved in establishing the dorsal identity program and its role is to regulate the domain of activity of <italic>DIV</italic> (the ventral identity program) by restricting it to ventral regions of the flower.</p> </list-item> <list-item> <p> <italic>Plantago</italic> is in the same family as <italic>Antirrhinum</italic> but has small, radially symmetrical (actinomorphic) flowers derived from a zygomorphic ancestral state. Here we investigate the MYB‐class floral symmetry genes and the role they have played in the evolution of derived actinomorphy in <italic>Plantago lanceolata</italic>.</p> </list-item> <list-item> <p>A <italic>DIV</italic> ortholog (<italic>PlDIV</italic>) but no <italic>RAD</italic> ortholog was identified in <italic>P. lanceolata</italic>. <italic>PlDIV</italic> is expressed across all petals and stamens later in flower development, which is consistent with the loss of <italic>RAD</italic> gene function. <italic>PlDIV</italic> expression in anther sporogenous tissue also suggests that <italic>PlDIV</italic> was co‐opted to regulate cell proliferation during the early stages of pollen development.</p> </list-item> <list-item> <p>These results indicate that evolution of derived actinomorphy in <italic>Plantago</italic> involved complete loss of dorsal gene function, resulting in expansion of the domain of expression of the ventral class of floral symmetry genes.</p> </list-item> </list> </p> </abstract>