This study is a thorough characterization of pigeonpea dirigent gene () family, an important component of the lignin biosynthesis pathway. Genome-wide analysis identified 25 genes followed by a range of analytical approaches employed to unravel their structural and functional characteristics. Structural examination revealed a classic single exon and no intron arrangement in DIRs contributing to our understanding on evolutionary dynamics. Phylogenetic analysis elucidated evolutionary relationships among genes with six DIR sub-families, while motif distribution analysis displayed and highlighted ten conserved protein motifs in DIRs. Promoter analyses of all the dirigent genes detected 18 stress responsive -acting elements offering insights into transcriptional regulation. While spatial expression analyses across six plant tissues showed preferential expression of genes, exposure to salt (DIR2 and DIR9) and herbivory (DIR1, DIR2, DIR3 and DIR11), demonstrated potential roles of specific DIRs in plant defense. Interestingly, increased gene expression during herbivory, also correlated with increased lignin content authenticating the specific response. Furthermore, exogenous application of stress hormones, SA and MeJA on leaves significantly induced the expression of DIRs that responded to herbivory. Taken together, these findings contribute to a comprehensive understanding of DIR genes impacting development and stress response in the important legume pigeonpea.

中文翻译：

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木豆 (Cajanus cajan L.) 中 DIRIGENT 基因家族 (CcDIR) 的全基因组鉴定和表征提供了对其空间表达模式及其与应激反应相关性的见解

本研究对木豆 dirigent 基因 () 家族进行了全面的表征，该基因是木质素生物合成途径的重要组成部分。全基因组分析确定了 25 个基因，随后采用一系列分析方法来揭示其结构和功能特征。结构检查揭示了 DIR 中的经典单外显子且无内含子排列，有助于我们对进化动力学的理解。系统发育分析阐明了具有六个 DIR 亚家族的基因之间的进化关系，而基序分布分析显示并突出了 DIR 中的 10 个保守蛋白基序。对所有定向基因的启动子分析检测到 18 个应激反应作用元件，为转录调控提供了见解。虽然六种植物组织的空间表达分析显示基因的优先表达，但暴露于盐（DIR2和DIR9）和草食（DIR1、DIR2、DIR3和DIR11），证明了特定DIR在植物防御中的潜在作用。有趣的是，食草过程中基因表达的增加也与木质素含量的增加相关，从而验证了特定的反应。此外，在叶片上外源施加应激激素SA和MeJA显着诱导响应草食的DIR的表达。总而言之，这些发现有助于全面了解 DIR 基因影响重要豆科木豆的发育和应激反应。