AtMIF1 increases seed oil content by attenuating GL2 inhibition
AtMIF1 increases seed oil content by attenuating GL2 inhibition
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AtMIF1 通过减弱 GL2 抑制来增加种子油含量。
DOI：
10.1111/nph.17016
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发表时间：
2020-11-29
期刊：
影响因子：
9.4
通讯作者：
Sun, Meng-Xiang
中科院分区：
文献类型：
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作者：
Cheng, Tianhe;Zhao, Peng;Sun, Meng-Xiang
植物油是主要的食用油和重要的工业原料。然而，育种者发现提高作物种子的含油量具有挑战性，并且对现代油料作物育种中通过分子工程提高含油量的调节剂知之甚少。我们报道了一种F-box蛋白，拟南芥MYB相互作用因子1（AtMIF 1），它是参与26 S蛋白酶体蛋白降解途径的泛素-蛋白连接酶E3复合物的成员。AtMIF 1与MYB结构域蛋白5（MYB 5）物理相互作用，这导致MYB 5降解，使得MYB/bHLH/WD-重复（MBW）复合物的转录激活不能正常发生，并且编码油含量抑制剂并作为MBW的直接下游基因起作用的GLABRA 2（GL 2）不能正确转录。AtMIF 1作为一个积极的调节剂，通过减弱GL 2抑制增加油含量。我们过量表达AtMIF 1，并获得了转基因植物具有显着更高的种子油含量。重要的是，转基因植物的营养生长和生殖生长都表现正常。总之，这项工作揭示了一种新的调节剂AtMIF 1和一种新的调节途径26 S蛋白酶体-AtMIF 1-MYB 5，用于增加种子的含油量而不影响植物生长，从而促进油料作物育种。
Vegetable oil is a major edible oil and an important industrial raw material. However, breeders have found it challenging to improve the oil content of crop seeds, and little is known about regulators with the potential to increase oil content via molecular engineering in modern oil crop breeding. We reported an F-box protein, Arabidopsis thaliana MYB Interaction Factor 1 (AtMIF1), which is a member of the ubiquitin-protein ligase E3 complex involved in the 26S proteasome protein degradation pathway. AtMIF1 physically interacts with MYB domain protein 5 (MYB5), which results in MYB5 degradation, so that transcriptional activation of the MYB/bHLH/WD-repeat (MBW) complex does not occur normally and GLABRA2 (GL2), encoding an inhibitor of oil content and functioning as a direct downstream gene of MBW, is not properly transcribed. AtMIF1 functioned as a positive regulator that increases oil content by attenuating GL2 inhibition. We overexpressed AtMIF1 and obtained transgenic plants with significantly higher seed oil contents. Importantly, both vegetative and reproductive growth of the transgenic plants appeared normal. In summary, this work reveals a novel regulator, AtMIF1, and a new regulatory pathway, 26S proteasome-AtMIF1-MYB5, for increasing the oil content of seeds without affecting plant growth, thus facilitating oil crop breeding.