Walnut is a popular nut tree species and usually suffers from drought stress. However, little information is available on the mechanism of walnut responding to drought stress, resulting in lack of basic understanding for its resistance. In order to excavate more functional genes that can respond to stressors, and enrich the theoretical basis for walnut resistance, in this study, 5 MYB genes with complete ORFs were identified from J. regia and the basic bio-information as well as expression patterns in different tissues and response to drought and ABA stresses were confirmed using qRT-PCR assay. The results showed that 2 JrMYB genes belong to R1-MYB subfamily and 3 JrMYBs belong to R2R3-MYB, encoding the proteins from 212 to 362 aa in length. The phylogenetic analysis categorized proteins of 5 JrMYBs and 40 Arabidopsis AtMYBs into 10 subgroups. JrMYBs in the same subgroup exhibited significant similarities in the composition of conserved domains and motifs in amino acid sequences and exon/intron organization in DNA sequences. The results of qRT-PCR analysis revealed that JrMYB genes diversely expressed in various tissues. Moreover, the expression values of JrMYBs were upregulated or downregulated significantly under drought and ABA stresses. Most attractively, in contrast with suffering from drought stress alone, the treatments with drought and additional ABA greatly enhanced the transcript levels of JrMYBs. All these results suggested that JrMYB genes play a vital role in plant biological processes and drought as well as ABA stress response, and possibly perform as ABA-dependent drought response transcription factors in plant.

核桃是一种流行的坚果树种，通常遭受干旱压力。然而，关于核桃对干旱胁迫的响应机制的信息很少，导致对其抗性缺乏基本的了解。为了挖掘更多能够响应应激源的功能基因，丰富核桃抗性的理论基础，本研究从帝王核桃中鉴定出5个具有完整开放阅读框的MYB基因及其基本生物信息和表达模式。使用 qRT-PCR 分析证实了不同的组织以及对干旱和 ABA 胁迫的反应。结果表明2个JrMYB基因属于R1-MYB亚家族，3个JrMYBs属于R2R3-MYB，编码长度为 212 到 362 个氨基酸的蛋白质。系统发育分析将 5 个 JrMYBs 和 40 个拟南芥AtMYBs 的蛋白质分为 10 个亚组。同一亚组中的 JrMYB 在氨基酸序列中的保守结构域和基序的组成以及 DNA 序列中的外显子/内含子组织方面表现出显着的相似性。qRT-PCR 分析结果表明，JrMYB基因在各种组织中不同表达。此外，JrMYBs的表达值在干旱和 ABA 胁迫下显着上调或下调。最吸引人的是，与仅遭受干旱胁迫相比，干旱和额外 ABA 的处理大大提高了JrMYBs的转录水平. 所有这些结果表明，JrMYB基因在植物生物学过程和干旱以及ABA胁迫响应中发挥着至关重要的作用，并可能在植物中作为ABA依赖性干旱响应转录因子发挥作用。