The endosperm-specific transcription factor TaNAC019 regulates glutenin and starch accumulation and its elite allele improves wheat grain quality.
The endosperm-specific transcription factor TaNAC019 regulates glutenin and starch accumulation and its elite allele improves wheat grain quality.
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DOI：
10.1093/plcell/koaa040
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发表时间：
2021-05-05
期刊：
影响因子：
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通讯作者：
Yao Y
中科院分区：
文献类型：
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作者：
Gao Y;An K;Guo W;Chen Y;Zhang R;Zhang X;Chang S;Rossi V;Jin F;Cao X;Xin M;Peng H;Hu Z;Guo W;Du J;Ni Z;Sun Q;Yao Y
在小麦（Triticum aestivum L.）中，育种工作集中在提高粮食产量和品质上。在品质方面，种子贮藏蛋白的含量和组成决定了小麦面团的弹性和面粉加工品质。此外，种子中的淀粉水平与产量有关。然而，很少有人知道的机制，协调SSP和淀粉积累在小麦。在这项研究中，我们探讨了胚乳特异性NAC转录因子TaNAC 019在协调SSP和淀粉积累中的作用。TaNAC 019与编码高分子量麦谷蛋白（HMW-GS）的TaGlu-1基因座和淀粉代谢基因的启动子结合。所有三个TaNAC 019同源物的三重敲除突变体表现出降低的转录水平的所有SSP类型和基因参与淀粉代谢，导致较低的面筋和淀粉含量，并在面粉加工品质参数。TaNAC 019通过与HMW-GS基因启动子中的特定基序结合并与TaGlu-1调节因子TaGAMyb相互作用，直接激活HMW-GS基因的表达。TaNAC 019还间接调节TaSPA的表达，TaSPA是玉米Opaque 2的直系同源物，其激活SSP积累。因此，TaNAC 019对淀粉和SSP相关基因的调控在小麦籽粒品质中具有关键作用。最后，我们确定了一个精英等位基因（TaNAC 019-BI）与面粉加工品质，提供了一个候选基因，用于育种与改善品质。小麦种子特异性转录因子TaNAC 019与TaGAMyb协同调控贮藏蛋白和淀粉积累，TaNAC 019-BI等位基因在育种上具有较高的加工品质候选基因。
In wheat (Triticum aestivum L.), breeding efforts have focused intensively on improving grain yield and quality. For quality, the content and composition of seed storage proteins (SSPs) determine the elasticity of wheat dough and flour processing quality. Moreover, starch levels in seeds are associated with yield. However, little is known about the mechanisms that coordinate SSP and starch accumulation in wheat. In this study, we explored the role of the endosperm-specific NAC transcription factor TaNAC019 in coordinating SSP and starch accumulation. TaNAC019 binds to the promoters of TaGlu-1 loci, encoding high molecular weight glutenin (HMW-GS), and of starch metabolism genes. Triple knock-out mutants of all three TaNAC019 homoeologs exhibited reduced transcript levels for all SSP types and genes involved in starch metabolism, leading to lower gluten and starch contents, and in flour processing quality parameters. TaNAC019 directly activated the expression of HMW-GS genes by binding to a specific motif in their promoters and interacting with the TaGlu-1 regulator TaGAMyb. TaNAC019 also indirectly regulated the expression of TaSPA, an ortholog of maize Opaque2 that activates SSP accumulation. Therefore, TaNAC019 regulation of starch- and SSP-related genes has key roles in wheat grain quality. Finally, we identified an elite allele (TaNAC019-BI) associated with flour processing quality, providing a candidate gene for breeding wheat with improved quality. The wheat seed-specific transcription factor TaNAC019 regulates storage protein and starch accumulation by cooperating with TaGAMyb, and the TaNAC019-BI allele is candidate for higher processing quality in breeding.