An endoplasmic reticulum-associated degradation-related E2-E3 enzyme pair controls grain size and weight through the brassinosteroid signaling pathway in rice
An endoplasmic reticulum-associated degradation-related E2-E3 enzyme pair controls grain size and weight through the brassinosteroid signaling pathway in rice
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DOI：
10.1093/plcell/koac364
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发表时间：
2022-12-15
期刊：
影响因子：
11.6
通讯作者：
Li, Yunhai
中科院分区：
文献类型：
--
作者：
Li, Jing;Zhang, Baolan;Li, Yunhai
籽粒大小是一项重要的农艺性状，但我们对作物籽粒大小测定的认识还很有限。内质网相关降解(ERAD)是一种特殊的泛素蛋白酶体系统，参与降解内质网中错误折叠或不完全折叠的蛋白质。在这里，我们报道了与ERAD相关的E2-E3酶对小颗粒3(SMG3)和减小颗粒大小1(DGS1)通过油菜素类固醇(BR)信号通路调节水稻籽粒大小和重量。SMG3编码拟南芥泛素结合酶32的同源物，该酶是一种与ERAD相关的保守的E2泛素结合酶。SMG3与另一种颗粒大小调节因子DGS1相互作用。SMG3或DGS1功能丧失导致小颗粒，而SMG3或DGS1过表达导致长颗粒。进一步分析表明，DGS1是一种活性较强的E3泛素连接酶，与SMG3共定位于内质网。SMG3和DGS1参与BR信号转导。DGS1泛素化BR受体油菜素类固醇不敏感1(BRI1)并影响其蓄积。遗传分析表明，SMG3、DGS1和BRI1共同作用于调节籽粒大小和重量。综上所述，我们的发现发现了一个调节籽粒大小和重量的ERAD相关的E2-E3对，这使得我们深入了解了ERAD在籽粒大小控制和BR信号转导中的功能。内质网相关的降解相关的E2-E3对通过油菜素类固醇信号通路影响水稻的籽粒大小。
Grain size is an important agronomic trait, but our knowledge about grain size determination in crops is still limited. Endoplasmic reticulum (ER)-associated degradation (ERAD) is a special ubiquitin proteasome system that is involved in degrading misfolded or incompletely folded proteins in the ER. Here, we report that SMALL GRAIN 3 (SMG3) and DECREASED GRAIN SIZE 1 (DGS1), an ERAD-related E2-E3 enzyme pair, regulate grain size and weight through the brassinosteroid (BR) signaling pathway in rice (Oryza sativa). SMG3 encodes a homolog of Arabidopsis (Arabidopsis thaliana) UBIQUITIN CONJUGATING ENZYME 32, which is a conserved ERAD-associated E2 ubiquitin conjugating enzyme. SMG3 interacts with another grain size regulator, DGS1. Loss of function of SMG3 or DGS1 results in small grains, while overexpression of SMG3 or DGS1 leads to long grains. Further analyses showed that DGS1 is an active E3 ubiquitin ligase and colocates with SMG3 in the ER. SMG3 and DGS1 are involved in BR signaling. DGS1 ubiquitinates the BR receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1) and affects its accumulation. Genetic analysis suggests that SMG3, DGS1, and BRI1 act together to regulate grain size and weight. In summary, our findings identify an ERAD-related E2-E3 pair that regulates grain size and weight, which gives insight into the function of ERAD in grain size control and BR signaling.An endoplasmic reticulum-associated degradation-related E2-E3 pair affects grain size in rice through the brassinosteroid signaling pathway.