AUTHOR=Zeng Xiaoxue , Tagiri Akemi , Kikuchi Shinji , Sassa Hidenori , Komatsuda Takao 

TITLE=The Ectopic Expression of Btr2 in Aegilops tauschii Switches the Disarticulation Layer From Above to Below the Rachis Node

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.582622

DOI=10.3389/fpls.2020.582622

ISSN=1664-462X

ABSTRACT=<p>Seed dispersal among wild species belonging to the tribe Triticeae is typically achieved by the formation of a brittle rachis. The trait relies on the development of a disarticulation layer, most frequently above the rachis node (resulting in wedge type dispersal units), but in some species below the rachis node (resulting in barrel type dispersal units). The genes responsible for the former type are the complementary pair <italic>Btr1</italic> and <italic>Btr2</italic>, while the genetic basis of the latter type has yet to be determined. <italic>Aegilops tauschii</italic> forms barrel type dispersal units and previous study showed this species lacked an intact copy of <italic>Btr1</italic>. Here it has been demonstrated that <italic>Ae. tauschii</italic> carries two of <italic>Btr2</italic>; and that <italic>Btr2</italic> transcript is present in a region below the rachis node where the abscission zone forms. The implication is that in this species, the <italic>Btr2</italic> product is involved in the formation of barrel type dispersal units.</p>