SEEDSTICK Controls Arabidopsis Fruit Size by Regulating Cytokinin Levels and FRUITFULL

0524174 - ÚEB 2021 RIV US eng J - Journal Article
Di Marzo, M. - Herrera-Ubaldo, H. - Caporali, E. - Novák, Ondřej - Strnad, Miroslav - Balanzà, V. - Ezquer, I. - Mendes, M.A. - de Folter, S. - Colombo, L.
SEEDSTICK Controls Arabidopsis Fruit Size by Regulating Cytokinin Levels and FRUITFULL.
Cell Reports. Roč. 30, č. 8 (2020), s. 2846-2857. ISSN 2211-1247. E-ISSN 2211-1247
R&D Projects: GA ČR(CZ) GA18-07563S
Institutional support: RVO:61389030
Keywords : Arabidopsis * cell elongation * ckx7 * cytokinins * fruit size * fruitfull * MADS-box * seedstick
OECD category: Biochemistry and molecular biology
Impact factor: 9.423, year: 2020
Method of publishing: Open access
http://doi.org/10.1016/j.celrep.2020.01.101

Upon fertilization, the ovary increases in size and undergoes a complex developmental process to become a fruit. We show that cytokinins (CKs), which are required to determine ovary size before fertilization, have to be degraded to facilitate fruit growth. The expression of CKX7, which encodes a cytosolic CK-degrading enzyme, is directly positively regulated post-fertilization by the MADS-box transcription factor STK. Similar to stk, two ckx7 mutants possess shorter fruits than wild type. Quantification of CKs reveals that stk and ckx7 mutants have high CK levels, which negatively control cell expansion during fruit development, compromising fruit growth. Overexpression of CKX7 partially complements the stk fruit phenotype, confirming a role for CK degradation in fruit development. Finally, we show that STK is required for the expression of FUL, which is essential for valve elongation. Overall, we provide insights into the link between CKs and molecular pathways that control fruit growth.
Permanent Link: http://hdl.handle.net/11104/0308537