AUTHOR=Zeng Xiaoxue , Mishina Kohei , Jia Juqing , Distelfeld Assaf , Maughan Peter Jeff , Kikuchi Shinji , Sassa Hidenori , Komatsuda Takao 

TITLE=The Brittle Rachis Trait in Species Belonging to the Triticeae and Its Controlling Genes Btr1 and Btr2

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.01000

DOI=10.3389/fpls.2020.01000

ISSN=1664-462X

ABSTRACT=<p>In many non-cultivated angiosperm species, seed dispersal is facilitated by the shattering of the seed head at maturity; in the Triticeae tribe, to which several of the world's most important cereals belong, shattering takes the form of a disarticulation of the rachis. The products of the genes <italic>Btr1</italic> and <italic>Btr2</italic> are both required for disarticulation to occur above the rachis nodes within the genera <italic>Hordeum</italic> (barley) and <italic>Triticum/Aegilops</italic> (wheat). Here, it has been shown that both <italic>Btr1</italic> and <italic>Btr2</italic> are specific to the Triticeae tribe, although likely paralogs (<italic>Btr1-like</italic> and <italic>Btr2-like</italic>) are carried by the family Poaceae including Triticeae<italic>. Aegilops tauschii</italic> (the donor of the bread wheat D genome) lacks a copy of <italic>Btr1</italic> and disarticulation in this species occurs below, rather than above the rachis node; thus, the product of <italic>Btr1</italic> appears to be required for disarticulation to occur above the rachis node.</p>