SEEDSTICK Controls Arabidopsis Fruit Size by Regulating Cytokinin Levels and FRUITFULL
SEEDSTICK Controls Arabidopsis Fruit Size by Regulating Cytokinin Levels and FRUITFULL
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DOI：
10.1016/j.celrep.2020.01.101
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发表时间：
2020-02-25
期刊：
影响因子：
8.8
通讯作者：
Colombo, Lucia
中科院分区：
文献类型：
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作者：
Di Marzo, Maurizio;Herrera-Ubaldo, Humberto;Colombo, Lucia
受精后，卵巢增大，并经历一个复杂的发育过程成为果实。我们发现，在受精前决定卵巢大小所需的细胞分裂素(CKs)必须被降解以促进果实的生长。CKX7编码胞浆CK降解酶，受精后受MADS-box转录因子STK直接正向调控。与StK相似，2个ck x7突变体的果实比野生型短。CKS的定量分析表明，StK和CK7突变体具有较高的CK水平，这对果实发育过程中的细胞扩张起到了负面的控制作用，从而影响了果实的生长。CKX7的过度表达部分补充了StK果实的表型，证实了CK降解在果实发育中的作用。最后，我们证明STK是FUL表达所必需的，而FUL是瓣膜延长所必需的。总体而言，我们提供了对CKS和控制水果生长的分子途径之间的联系的见解。
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.