Downregulation of a gibberellin 3β-hydroxylase enhances photosynthesis and increases seed yield in soybean
Downregulation of a gibberellin 3β-hydroxylase enhances photosynthesis and increases seed yield in soybean
复制标题
赤霉素 3β-羟化酶的下调增强光合作用并增加大豆种子产量。
DOI：
10.1111/nph.18153
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发表时间：
2022-04-28
期刊：
影响因子：
9.4
通讯作者：
Yu, Deyue
中科院分区：
文献类型：
--
作者：
Hu, Dezhou;Li, Xiao;Yu, Deyue
种子产量是大豆育种的首要目标，种子产量主要由种子数和粒重决定。确定产量相关性状的基因具有重要意义。通过联合连锁定位和百粒重全基因组关联研究，克隆了赤霉素3β羟基酶编码基因GmGA3ox1，该酶是赤霉素合成途径中的关键酶。基因组重测序证实了一个有益的GmGA3ox1单倍型，这一点在大豆转化体中得到了进一步的证实。CRISPR/Cas9产生的gmga3ox1突变体表现出较低的粒重，但通过增加种子数来促进种子产量。Gmga3ox1突变体减少了赤霉素的生物合成，同时增强了光合作用。GmGA3ox1基因的敲除导致了许多光合作用相关基因的上调，特别是编码核酮糖-1，5-二磷酸羧基加氧酶(Rubisco)激活酶的GmRCA家族。碱性亮氨酸拉链转录因子GmBZIP97和GmBZIP159在赤霉素化合成抑制剂烯效唑诱导下均能与GmRCAβ启动子结合并激活其表达。对2700多份大豆种质的基因组序列分析表明，GmGA3ox1正逐步在现代育种中得到利用。我们的结果阐明了GmGA3ox1在大豆产量中的重要作用。这些发现为未来大豆和其他作物的高产育种提供了重要线索。
Seed yield, determined mainly by seed numbers and seed weight, is the primary target of soybean breeding. Identifying the genes underlying yield-related traits is of great significance. Through joint linkage mapping and a genome-wide association study for 100-seed weight, we cloned GmGA3ox1, a gene encoding gibberellin 3β-hydroxylase which is the key enzyme in the gibberellin synthesis pathway. Genome resequencing identified a beneficial GmGA3ox1 haplotype contributing to high seed weight, which was further confirmed by soybean transformants. CRISPR/Cas9-generated gmga3ox1 mutants showed lower seed weight, however promoted seed yield by increasing seed numbers. The gmga3ox1 mutants reduced gibberellin biosynthesis while enhancing photosynthesis. Knockout of GmGA3ox1 resulted in the upregulation of numerous photosynthesis-related genes, particularly the GmRCA family encoding ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) activases. The basic leucine zipper transcription factors GmbZIP97 and GmbZIP159, which were upregulated both in the gmga3ox1 mutants and induced by the gibberellin synthesis inhibitor uniconazole, could bind to the promoter of GmRCAβ and activate its expression. Analysis of genomic sequences with over 2700 soybean accessions suggested that GmGA3ox1 is being gradually utilized in modern breeding. Our results elucidated the important role of GmGA3ox1 in soybean yield. These findings reveal important clues for future high-yield breeding in soybean and other crops.