The EPIDERMAL PATTERNING FACTOR (EPF) and EPF-LIKE (EPFL) family of small secreted peptides act to regulate many aspects of plant growth and development; however, their functions are not widely characterized in rice (Oryza sativa). Here, we used clustered regularly interspaced short palindromic repeats (CRISPR/Cas9) technology to individually knockout each of 11 EPF/EPFL genes in the rice cultivar Kasalath. Loss of function of most OsEPF/EPFL genes generated no obvious phenotype alteration, while disruption of OsEPFL2 in Kasalath caused a short or no awn phenotype and reduced grain size. OsEPFL2 is strongly expressed in the young panicle, consistent with a role in regulating awn and grain development. Haplotype analysis indicated that OsEPFL2 can be classified into six major haplotypes. Nucleotide diversity and genetic differentiation analyses suggested that OsEPFL2 was positively selected during the domestication of rice. Our work to systematically investigate the function of EPF/EPFL peptides demonstrates that different members of the same gene family have been independently selected for their ability to regulate a similar biological function and provides perspective on rice domestication.

中文翻译：

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小表皮模式因子样 2 肽调节水稻芒发育。

表皮模式因子 (EPF) 和 EPF-LIKE (EPFL) 家族的小分泌肽可调节植物生长和发育的许多方面；然而，它们的功能在水稻 (Oryza sativa) 中并未得到广泛表征。在这里，我们使用成簇规律间隔的短回文重复序列 (CRISPR/Cas9) 技术分别敲除水稻品种 Kasalath 中的 11 个 EPF/EPFL 基因。大多数 OsEPF/EPFL 基因的功能丧失不会产生明显的表型改变，而 Kasalath 中 OsEPFL2 的破坏会导致短芒或无芒表型并减小晶粒尺寸。OsEPFL2 在幼穗中强烈表达，与调节芒和谷粒发育的作用一致。单倍型分析表明OsEPFL2可分为六大单倍型。核苷酸多样性和遗传分化分析表明，OsEPFL2 在水稻驯化过程中被积极选择。我们系统研究 EPF/EPFL 肽功能的工作表明，同一基因家族的不同成员已被独立选择，因为它们具有调节相似生物学功能的能力，并为水稻驯化提供了视角。