Cup-shaped Cotyledon1 (CUC1) and CU2 regulate cytokinin homeostasis to determine ovule number in arabidopsis Journal Article


Author(s): Cucinotta, Mara; Manrique, Silvia; Cuesta, Candela; Benková, Eva; Novák, Ondřej; Colombo, Lucia
Article Title: Cup-shaped Cotyledon1 (CUC1) and CU2 regulate cytokinin homeostasis to determine ovule number in arabidopsis
Affiliation IST Austria
Abstract: Seeds derive from ovules upon fertilization and therefore the total number of ovules determines the final seed yield, a fundamental trait in crop plants. Among the factors that co-ordinate the process of ovule formation, the transcription factors CUP-SHAPED COTYLEDON 1 (CUC1) and CUC2 and the hormone cytokinin (CK) have a particularly prominent role. Indeed, the absence of both CUC1 and CUC2 causes a severe reduction in ovule number, a phenotype that can be rescued by CK treatment. In this study, we combined CK quantification with an integrative genome-wide target identification approach to select Arabidopsis genes regulated by CUCs that are also involved in CK metabolism. We focused our attention on the functional characterization of UDP-GLUCOSYL TRANSFERASE 85A3 (UGT85A3) and UGT73C1, which are up-regulated in the absence of CUC1 and CUC2 and encode enzymes able to catalyse CK inactivation by O-glucosylation. Our results demonstrate a role for these UGTs as a link between CUCs and CK homeostasis, and highlight the importance of CUCs and CKs in the determination of seed yield.
Journal Title: Journal of Experimental Botany
Volume: 69
Issue 21
ISSN: 1460-2431
Publisher: Oxford University Press  
Date Published: 2018-07-26
Start Page: 5169
End Page: 5176
Copyright Statement: CC BY 4.0
Sponsor: This work was funded by the Ministry of Education, Youth and Sports of the Czech Republic through the National Program of Sustainability (grant no. LO1204).
DOI: 10.1093/jxb/ery281
Open access: yes (OA journal)