The basic leucine zipper (bZIP) is a transcription factor broadly found in higher plants and is involved in numerous crucial physiological processes: growth and development, stress responses, etc. The pecan (Carya illinoinensis) is a highly ornamental and economical woody plant that is popular in landscape and economic forestry. However, the identification and analysis of the bZIP TF system in pecan have not been reported. To acquire information on the bZIP gene family in pecan, we appraised 77 members of the bZIP gene family from the pecan genome and categorized them into 12 subfamilies (S, B, A, D, F, E, G, I, J, H, K, and C) using bioinformatics methods. Analysis in terms of gene structure and conserved motif composition revealed that each subtribe shares a comparable number of introns-exons and functions. Ka/Ks results suggested that bZIP evolution was influenced by purifying selection. The promoter cis-acting element analysis revealed a huge number of abscisic acid–responsive elements, light-responsive elements, and jasmonic acid–responsive elements in pecan bZIPs. Furthermore, the protein interaction network predicted a possible role for S1-bZIPs in abiotic stress, and the qRT-PCR results further demonstrated that this subpopulation responds to abiotic stress. Meanwhile, the results of subcellular localization and transcriptional activity indicated that CibZIP38, CibZIP55, and CibZIP43 are all nuclear-localized transcriptional activators. The report of the pecan bZIP gene family in this work can further improve our understanding of CibZIPs as a genetic resource for the genetic engineering breeding of pecan.

碱性亮氨酸拉链（bZIP）是高等植物中广泛存在的转录因子，参与许多重要的生理过程：生长发育、应激反应等。山核桃（Carya illinoinensis）是一种高度观赏性和经济性的木本植物，流行于景观和经济林业。然而，对山核桃bZIP TF系统的鉴定和分析尚未见报道。为了获取山核桃bZIP基因家族的信息，我们评估了山核桃基因组中bZIP基因家族的77个成员，并将它们分为12个亚家族（S、B、A、D、F、E、G、I、J、H） 、K 和 C) 使用生物信息学方法。基因结构和保守基序组成的分析表明，每个亚族具有相当数量的内含子-外显子和功能。Ka/Ks 结果表明bZIP进化受到纯化选择的影响。启动子顺式作用元件分析显示山核桃bZIPs中存在大量脱落酸响应元件、光响应元件和茉莉酸响应元件。此外，蛋白质相互作用网络预测了 S1-bZIPs 在非生物胁迫中可能发挥的作用，qRT-PCR 结果进一步证明该亚群对非生物胁迫有反应。同时，亚细胞定位和转录活性结果表明CibZIP38、CibZIP55和CibZIP43都是核定位的转录激活因子。本工作对山核桃bZIP基因家族的报道可以进一步提高我们对CibZIPs作为山核桃基因工程育种遗传资源的认识。