The APETALA2-Like Transcription Factor SUPERNUMERARY BRACT Controls Rice Seed Shattering and Seed Size
The APETALA2-Like Transcription Factor SUPERNUMERARY BRACT Controls Rice Seed Shattering and Seed Size
复制标题
APETALA2样转录因子SUPERNUMERARY BRACT控制水稻种子的落粒和种子大小
DOI：
10.1105/tpc.18.00304
复制
发表时间：
2019-01-01
期刊：
影响因子：
11.6
通讯作者：
Tan, Lubin
中科院分区：
文献类型：
--
作者：
Jiang, Liyun;Ma, Xin;Tan, Lubin
消除种子碎裂是作物驯化过程中的一个关键事件。改进和微调这一过程的调控将进一步提高粮食产量，避免作物生产过程中的种子损失。在这项工作中，我们通过筛选具有天然高碎裂性的诱变野生稻（Oryza rufipogon）渗入系，鉴定了碎裂丧失突变体抑制碎裂1 （ssh1）。利用MutMap方法和转化实验，我们分离到了一个影响种子碎裂的遗传因子SSH1，它是SUPERNUMERARY BRACT （SNB）基因的一个等位基因，SNB基因编码一个植物特异性的apetala2样转录因子。SNB第9个内含子的C-to-A点突变改变了其信使RNA的剪接，通过改变种子和花梗交界处的脱落层和维管束的发育，导致ssh1突变体的碎裂减少。我们的数据表明，SNB正调控两个水稻replmless同源基因qSH1和SH5的表达。此外，突变体ssh1的种子更大，粒重更高，这是由于其颖片纵向细胞的伸长增加所致。进一步鉴定SNB有利等位基因，将为利用分子育种策略提高水稻籽粒结实性和籽粒产量提供参考。
The elimination of seed shattering was a crucial event during crop domestication. Improving and fine-tuning the regulation of this process will further enhance grain yield by avoiding seed losses during crop production. In this work, we identified the loss-of-shattering mutant suppression of shattering1 (ssh1) through a screen of mutagenized wild rice (Oryza rufipogon) introgression lines with naturally high shattering. Using the MutMap approach and transformation experiments, we isolated a genetic factor for seed shattering, SSH1, which is an allele of SUPERNUMERARY BRACT (SNB), a gene encoding a plantspecific APETALA2-like transcription factor. A C-to-A point mutation in the ninth intron of SNB altered the splicing of its messenger RNA, causing the reduced shattering of the ssh1 mutant by altering the development of the abscission layer and vascular bundle at the junction between the seed and the pedicel. Our data suggest that SNB positively regulates the expression of two rice REPLUMLESS orthologs, qSH1 and SH5. In addition, the ssh1 mutant had larger seeds and a higher grain weight, resulting from its increased elongation of the glume longitudinal cells. The further identification of favorable SNB alleles will be valuable for improving rice seed shattering and grain yield using molecular breeding strategies.