A genome-wide association study reveals a novel regulator of ovule number and fertility in Arabidopsis thaliana
A genome-wide association study reveals a novel regulator of ovule number and fertility in Arabidopsis thaliana
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DOI：
10.1101/356600
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发表时间：
2018-06
期刊：
影响因子：
4.5
通讯作者：
Jing Yuan;S. Kessler
中科院分区：
文献类型：
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作者：
Jing Yuan;S. Kessler
胚珠含有雌配子体，在授粉过程中受精，开始种子发育。因此，在花发育期间产生的胚珠的数量是种子作物产量和植物适合度的重要决定因素。对发育具有多效性效应的突变体通常会改变胚珠的数量，但在传统的突变体筛选中很难确定胚珠数量的特异性调节因子。我们利用拟南芥种质的自然变异来鉴定参与胚珠数量调控的新基因。测定了189份拟南芥材料的每花胚珠数，发现它们具有广泛的表型变异，从每雌蕊39个胚珠到84个胚珠不等。全基因组关联测试揭示了几个与胚珠数量相关的基因组区域。从最显着相关位点的候选基因中的T-DNA插入系进行了筛选胚珠数表型。根矮化新增强子（NERD 1）基因对植物育性具有多效性，包括调节胚珠数量和雌雄配子体发育。NERD 1的过表达以背景依赖的方式增加了每个果实的胚珠数量，并且在所有测试的背景中产生的花的总数增加了一倍以上，这表明NERD 1水平的操纵可用于增加植物生产力。作者摘要胚珠是开花植物种子的前体。每个胚珠含有一个卵细胞和一个中央细胞，在双受精过程中与两个精细胞融合产生含有胚和胚乳的种子。在花发育过程中产生的胚珠数量决定了花可以产生的种子的最大数量。在本文中，我们利用拟南芥种质的自然变异来鉴定与胚珠数量相关的基因组区域。3号染色体上的植物特异性NERD 1基因的多态性与胚珠数显著相关。突变体和过表达分析表明，NERD 1是一个积极的调节胚珠数量，侧分枝，花的数量在拟南芥。操纵NERD 1表达水平可潜在地用于增加作物植物的产量。
Ovules contain the female gametophytes which are fertilized during pollination to initiate seed development. Thus, the number of ovules that are produced during flower development is an important determinant of seed crop yield and plant fitness. Mutants with pleiotropic effects on development often alter the number of ovules, but specific regulators of ovule number have been difficult to identify in traditional mutant screens. We used natural variation in Arabidopsis accessions to identify new genes involved in the regulation of ovule number. The ovule numbers per flower of 189 Arabidopsis accessions were determined and found to have broad phenotypic variation that ranged from 39 ovules to 84 ovules per pistil. Genome-Wide Association tests revealed several genomic regions that are associated with ovule number. T-DNA insertion lines in candidate genes from the most significantly associated loci were screened for ovule number phenotypes. The NEW ENHANCER of ROOT DWARFISM (NERD1) gene was found to have pleiotropic effects on plant fertility that include regulation of ovule number and both male and female gametophyte development. Overexpression of NERD1 increased ovule number per fruit in a background-dependent manner and more than doubled the total number of flowers produced in all backgrounds tested, indicating that manipulation of NERD1 levels can be used to increase plant productivity. Author Summary Ovules are the precursors of seeds in flowering plants. Each ovule contains an egg cell and a central cell that fuse with two sperm cells during double fertilization to generate seeds containing an embryo and endosperm. The number of ovules produced during flower development determines the maximum number of seeds that can be produced by a flower. In this paper, we used natural variation in Arabidopsis thaliana accessions to identify regions of the genome that are associated with ovule number. Polymorphisms in the plant-specific NERD1 gene on chromosome 3 were significantly associated with ovule number. Mutant and overexpression analyses revealed that NERD1 is a positive regulator of ovule number, lateral branching, and flower number in Arabidopsis. Manipulation of NERD1 expression levels could potentially be used to increase yield in crop plants.