Online ISSN : 1884-4154
Print ISSN : 0918-9726
ISSN-L : 0918-9726
Regular Paper
Genetic interactions between the CUP-SHAPED COTYLEDON and the BELLRINGER genes indicate their overlapping functions in carpel boundary development in Arabidopsis thaliana
Kayo YamamotoMasao TasakaMitsuhiro Aida
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Keywords: BLR, boundary, carpel, CUC, meristem

2021 Volume 33 Issue 1 Pages 95-100


During gynoecium development in Arabidopsis thaliana, two carpel primordia are initiated with their margins fused together, forming a hollow tube. The fused carpel margins, or carpel boundaries, generate ovules, septa, and repla, which are essential structures for successful reproduction and seed dispersal. The boundary-specific CUP-SHAPED COTYLEDON (CUC) genes CUC1, CUC2, and CUC3 serve overlapping and distinct roles in the development of various shoot organ boundaries. The redundant functions of CUC1 and CUC2 are particularly important for carpel margin development. Here we report genetic interactions between the CUC genes and BELL-class homeobox gene BELLRINGER (BLR), which is also required for carpel boundary development. The blr single mutant displayed a mild defect in septum formation, while the CUC gene single mutants exhibited little effect on septum morphology. However, the blr phenotype was enhanced by any of the CUC gene single mutations, indicating overlapping roles for the CUC and BLR genes during carpel boundary development. Furthermore, we found that the blr mutation also caused a mild increase in the number of carpel boundaries, and this phenotype was significantly enhanced by the cuc3 mutation. Together, our analyses indicate overlapping and unique functions of CUC and BLR in regulating at least two aspects of carpel boundary development: septum formation and the patterning of carpel boundaries.

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© 2021 The Japanese Society of Plant Morphology
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