关键词: 芦笋, Prx基因家族, 全基因组鉴定, 生物信息学, 表达分析

Abstract:

【Objective】The peroxiredoxin (Prx) gene family in garden asparagus was systematically identified at the genome-wide level. The tissue-specific expression profiles and responses to abiotic stress, dormancy, and dormancy release were comprehensively investigated, providing a critical foundation for further functional characterization and breeding applications of AoPrxs. 【Method】Using the genomic data of asparagus, the members of the Prx family were identified through bioinformatics methods. The physicochemical properties, subcellular localization, gene structures, and conserved motifs of the AoPrxs were predicted using ProtParam, Cell-PLoc 2.0, SWISS-MODEL, and MEME tools, respectively. The tissue-specific expression patterns of AoPrxs and their responses to diverse stresses, dormancy, and dormancy release were systematically analyzed using RNA-Seq data and real-time fluorescent quantitative PCR (qRT-PCR). 【Result】The AoPrx family contains six members, designated AoPrx1-AoPrx6, all of which contain the conserved PXXXTXXC sequence. Their amino acid sequences ranged from 162 to 268 residues, with molecular weights ranging from 17 397.96 to 29 246.45 Da. A total of 220 (38 types) cis-acting elements were identified in AoPrxs, including those involved in plant growth and development, stress response, hormone signaling, and light response. Collinearity analysis revealed that AoPrx has a higher homology with TaPrx and OsPrx. Phylogenetic analysis classified the AoPrxs into five subfamilies, each exhibiting highly conserved gene structures, amino acid sequences, and protein structures. Notably, AoPrx1 and AoPrx2 lack the ‘resolving’ Cys residue but exhibit greater similarity in both amino acid sequence and protein structure to members of the PrxⅡB subfamily than to those of the 1-Cys subfamily. Consequently, they were classified into the PrxⅠB subfamily. Tissue expression analysis showed that AoPrx2 is ubiquitously expressed across all tissues, in contrast to AoPrx5, which showed stamen-specific upregulation in supermale flowers. The expression profile under adverse stress conditions indicated that salt-alkali stress significantly upregulated AoPrx5 expression in the roots of asparagus seedlings. Additionally, salt, drought, and low-light treatments markedly enhanced AoPrx4 expression levels in the stems and leaves of asparagus seedlings, while infection by Phomopsis asparagi exerted an opposite regulatory effect on AoPrx4 expression. Furthermore, AoPrx2, AoPrx4, and AoPrx5 may also be involved in the regulatory processes of dormancy induction and release in asparagus. 【Conclusion】Six Prx family members were identified in the asparagus genome, distributed across five chromosomes. All members contained the conserved PXXXTXXC motif and were phylogenetically classified into five subfamilies. Expression profiling revealed subfunctionalization among Prx paralogs: AoPrx5 was closely associated with stamen development and root salt tolerance. AoPrx4 played a pivotal role in the responses of stem and leaf tissues to salt, drought, low-light conditions, and phomopsis asparagi stress. Moreover, AoPrx2, AoPrx4, and AoPrx5 were also involved in the regulation of asparagus dormancy induction and release.

Key words: Asparagus officinalis L., Prx gene family, genome-wide identification, bioinformatics, expression analysis