A critical role of the soybean evening complex in the control of photoperiod sensitivity and adaptation
A critical role of the soybean evening complex in the control of photoperiod sensitivity and adaptation
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DOI：
10.1073/pnas.2010241118
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发表时间：
2021-02-23
影响因子：
11.1
通讯作者：
Kong, Fanjiang
中科院分区：
文献类型：
--
作者：
Bu, Tiantian;Lu, Sijia;Kong, Fanjiang
光周期敏感性是植物适应性和作物生产的关键因素。在短日照植物大豆中，对低纬度环境的适应是通过J基因座的突变提供的，其赋予延长的开花期，从而提高产量。J作为拟南芥ELF 3的直系同源物的身份，昼夜节律晚上复合体（EC）的一个组成部分，意味着其他EC组件的直系同源物可能具有类似的作用。在这里，我们表明，两个大豆同源LUX ARRYTHMO与J相互作用，形成大豆EC。突变体的表征表明，这些基因在功能上是高度冗余的，但在短日照下一起对开花至关重要，其中lux 1 lux 2双突变体显示出极晚的开花和大规模延长的开花期。这种表型超过了迄今为止报道的任何大豆开花突变体的表型，并且强烈地使人联想到“马里兰州猛犸”烟草突变体，该突变体在Garner和Allard [W. W.加纳，H. A. Allard，J.Agric.Res.18，553-606（1920）]。我们进一步证明，J-LUX复合物抑制转录的关键开花抑制因子E1和它的两个同系物通过LUX结合位点在其启动子。这些结果表明，EC-E1相互作用在大豆光周期敏感性中具有核心作用，这一现象也是Garner和Allard首次描述的。因此，EC和E1家族基因可能构成具有精确开花时间适应性的大豆品种定制育种的关键目标，无论是通过自然变异的渐渗还是通过基因编辑产生新的突变体。
Photoperiod sensitivity is a key factor in plant adaptation and crop production. In the short-day plant soybean, adaptation to low latitude environments is provided by mutations at the J locus, which confer extended flowering phase and thereby improve yield. The identity of J as an ortholog of Arabidopsis ELF3, a component of the circadian evening complex (EC), implies that orthologs of other EC components may have similar roles. Here we show that the two soybean homeologs of LUX ARRYTHMO interact with J to form a soybean EC. Characterization of mutants reveals that these genes are highly redundant in function but together are critical for flowering under short day, where the lux1 lux2 double mutant shows extremely late flowering and a massively extended flowering phase. This phenotype exceeds that of any soybean flowering mutant reported to date, and is strongly reminiscent of the "Maryland Mammoth" tobacco mutant that featured in the seminal 1920 study of plant photoperiodism by Garner and Allard [W. W. Garner, H. A. Allard, J. Agric. Res. 18, 553-606 (1920)]. We further demonstrate that the J-LUX complex suppresses transcription of the key flowering repressor E1 and its two homologs via LUX binding sites in their promoters. These results indicate that the EC-E1 interaction has a central role in soybean photoperiod sensitivity, a phenomenon also first described by Garner and Allard. EC and E1 family genes may therefore constitute key targets for customized breeding of soybean varieties with precise flowering time adaptation, either by introgression of natural variation or generation of new mutants by gene editing.