Abstract: Floral organ formation has been the subject of intensive study for over 20 years, particularly in the model dicot species Arabidopsis thaliana. These studies have led to the establishment of a general model for the development of floral organs in higher plants, the so-called ABCDE model, in which floral whorl-specific combinations of class A, B, C, D, or E genes specify floral organ identity. In Arabidopsis, class A, B, C, D, E genes encode MADS-box transcription factors except for the class A gene APETALA2. Mutation of these genes induces floral organ homeosis. In this review, I focus on the roles of these homeotic genes in bread wheat (Triticum aestivum), particularly with respect to the ABCDE model. Pistillody, the homeotic transformation of stamens into pistil-like structures, occurs in cytoplasmic substitution (alloplasmic) wheat lines that have the cytoplasm of the related wild species Aegilops crassa. This phenomenon is a valuable tool for analysis of the wheat ABCDE model. Using an alloplasmic line, the wheat ortholog of DROOPING LEAF (TaDL), a member of the YABBY gene family, has been shown to regulate pistil specification. Here, I describe the current understanding of the ABCDE model for floral organ formation in wheat.
Keywords: ABCDE model; floral organ; homeotic gene; MADS-box gene; pistillody; wheat
Export to BibTeX
MDPI and ACS Style
Murai, K. Homeotic Genes and the ABCDE Model for Floral Organ Formation in Wheat. Plants 2013, 2, 379-395.
Murai K. Homeotic Genes and the ABCDE Model for Floral Organ Formation in Wheat. Plants. 2013; 2(3):379-395.
Murai, Koji. 2013. "Homeotic Genes and the ABCDE Model for Floral Organ Formation in Wheat." Plants 2, no. 3: 379-395.