Genetic Control of Seed Shattering in Rice by the APETALA2 Transcription Factor SHATTERING ABORTION1
Genetic Control of Seed Shattering in Rice by the APETALA2 Transcription Factor SHATTERING ABORTION1
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DOI：
10.1105/tpc.111.094383
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发表时间：
2012-03-01
期刊：
影响因子：
11.6
通讯作者：
Han, Bin
中科院分区：
文献类型：
--
作者：
Zhou, Yan;Lu, Danfeng;Han, Bin
碎粒是作物驯化过程中重要的农业性状。在水稻驯化过程中，已鉴定出4号染色体籽粒破碎数量性状位点SH4和1号染色体籽粒破碎数量性状位点qSH1是减少水稻籽粒破碎所必需的基因。然而，水稻落粒的调控途径尚不清楚。在此，我们鉴定了一个野生水稻渐渗系的碎粒流产突变体（shat1）。SHAT1基因编码一个aptala2转录因子，通过指定水稻的脱落区（脱落区）发育，是水稻种子破碎所必需的。遗传分析表明，sht1在AZ中的表达受三螺旋转录因子SH4的正调控。我们还发现了一个SH4的移码突变体，它完全消除了AZs并表现出不碎裂。我们的研究结果表明，在一个遗传模型中，在颖花发育早期，活性的SHAT1和SH4在AZ中持续和集中表达是确定AZ的必要条件。qSH1作用于SHAT1和SH4的下游，通过维持SHAT1和SH4在AZ中的表达，从而促进AZ分化。
Seed shattering is an important agricultural trait in crop domestication. SH4 (for grain shattering quantitative trait locus on chromosome 4) and qSH1 (for quantitative trait locus of seed shattering on chromosome 1) genes have been identified as required for reduced seed shattering during rice (Oryza sativa) domestication. However, the regulatory pathways of seed shattering in rice remain unknown. Here, we identified a seed shattering abortion1 (shat1) mutant in a wild rice introgression line. The SHAT1 gene, which encodes an APETALA2 transcription factor, is required for seed shattering through specifying abscission zone (AZ) development in rice. Genetic analyses revealed that the expression of SHAT1 in AZ was positively regulated by the trihelix transcription factor SH4. We also identified a frameshift mutant of SH4 that completely eliminated AZs and showed nonshattering. Our results suggest a genetic model in which the persistent and concentrated expression of active SHAT1 and SH4 in the AZ during early spikelet developmental stages is required for conferring AZ identification. qSH1 functioned downstream of SHAT1 and SH4, through maintaining SHAT1 and SH4 expression in AZ, thus promoting AZ differentiation.