Variation and Inheritance of Small RNAs in Maize Inbreds and F1 Hybrids
Variation and Inheritance of Small RNAs in Maize Inbreds and F1 Hybrids
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DOI：
10.1104/pp.19.00817
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发表时间：
2020-01-01
期刊：
影响因子：
7.4
通讯作者：
Springer, Nathan M.
中科院分区：
文献类型：
--
作者：
Crisp, Peter A.;Hammond, Reza;Springer, Nathan M.
小RNA(SRNAs)调节基因表达，在表观遗传途径中发挥重要作用，并被认为对植物的杂交活力有贡献。以前的研究已经对sRNA和杂种优势之间的关系提供了有价值的见解，通常使用单一的杂交基因或组织，但我们对sRNAs的作用及其在植物育种中的潜在价值的理解受到不同基因类型和发育阶段之间sRNA变异的不完整图景的限制。在这里，我们对来自8个自交系亲本和12个杂交基因型的108个玉米(Zea Mays)样本的5个组织的sRNA变异和遗传进行了深入的探索，涵盖了各种性状的杂种优势群、遗传变异和杂种优势水平。我们记录了对sRNA表达的实质性的发育和基因类型的影响，21-核苷酸(NT)、22-NT和24-NT的sRNAs的模式不同。我们提供了玉米基因组中sRNAs分布的详细视图，揭示了一种复杂的结构，也显示了发育可塑性，特别是22-nt sRNAs。与观察到的基因表达差异相比，sRNA在自交系之间表现出更多的差异。在杂交种中，我们识别出非加性遗传的特定座位的例子，大多数表现为部分或完全显性，但很少超出亲本范围。然而，21-nt、22-nt和24-nt sRNAs的全球丰度在自交系和杂交种之间差异很小，这表明杂交主要在特定的座位上影响sRNA的表达，而不是在全球范围内。这项研究为理解sRNA在杂种优势中的潜在作用提供了有价值的资源。
Small RNAs (sRNAs) regulate gene expression, play important roles in epigenetic pathways, and are hypothesized to contribute to hybrid vigor in plants. Prior investigations have provided valuable insights into associations between sRNAs and heterosis, often using a single hybrid genotype or tissue, but our understanding of the role of sRNAs and their potential value to plant breeding are limited by an incomplete picture of sRNA variation between diverse genotypes and development stages. Here, we provide a deep exploration of sRNA variation and inheritance among a panel of 108 maize (Zea mays) samples spanning five tissues from eight inbred parents and 12 hybrid genotypes, covering a spectrum of heterotic groups, genetic variation, and levels of heterosis for various traits. We document substantial developmental and genotypic influences on sRNA expression, with varying patterns for 21-nucleotide (nt), 22-nt, and 24-nt sRNAs. We provide a detailed view of the distribution of sRNAs in the maize genome, revealing a complex makeup that also shows developmental plasticity, particularly for 22-nt sRNAs. sRNAs exhibited substantially more variation between inbreds as compared with observed variation for gene expression. In hybrids, we identify locus-specific examples of nonadditive inheritance, mostly characterized as partial or complete dominance, but rarely outside the parental range. However, the global abundance of 21-nt, 22-nt, and 24-nt sRNAs varies very little between inbreds and hybrids, suggesting that hybridization affects sRNA expression principally at specific loci rather than on a global scale. This study provides a valuable resource for understanding the potential role of sRNAs in hybrid vigor.