Genome-wide identification of the laccase gene family in wheat (Triticum aestivum L.) during Fusarium pseudograminearum infection
Liyu Chen, Yi Diao, Juhong Ma, Xiangxue Zhang, Rui Li, Yan Liu, Hongtao Tang, Zhi Wang, Sha Gao, Ruihuan Xu, Zhensheng Kang, Dejun Han, Qingdong Zeng
Plant Science
DOI: https://doi.org/10.1016/j.plantsci.2025.112894
Abstract
Laccases (EC 1.10.3.2, LAC) are ubiquitous enzymes involved in lignification and stress adaptation in plants. Although defense-induced lignification is a conserved mechanism of immunity, the role of wheat LAC in responding to Fusarium pseudograminearum (Fpg) infection remains underexplored. In this study, 98 LAC genes were identified in wheat (Triticum aestivum L.), unevenly distributed across all 21 chromosomes. Based on amino acid sequence similarity and following the AtLAC classification method, they were classified into six groups. TaLACs in the same cluster share similar gene structures and conserved protein motifs. Synteny analysis indicated that WGD and segmental duplication mainly drove TaLACs expansion. Cis-acting element analysis showed that TaLACs are involved in light response, plant hormone response, abiotic/biotic stress response, and growth. Expression patterns of TaLACs vary significantly in different tissues and developmental stages, echoing their abundant cis-acting elements. Moreover, multiple TaLACs were up-regulated during infection by Fpg. Transcriptomic analysis revealed that TaLAC72 was a candidate gene for Fusarium crown rot (FCR) resistance. TaLAC72 encodes a 599-aa protein with a secretion-signal peptide, is primarily localized to the plasma membrane, and shows granular aggregation in the cytoplasm. Silencing of TaLAC72 by BSMV-VIGS led to reduced lignin content from 102 mg/g DW to 60–40 mg/g DW, corresponding to a 41–61 % decrease and significant decline in FCR resistance. This study comprehensively analyzed TaLACs and found that TaLAC72 is a wheat FCR resistance gene, highlighting its key role in resisting infection by Fpg. Overall, our findings enhance understanding of the LAC family in wheat and provide a valuable resource for further investigation of these genes in FCR response.