Abstract
BACKGROUND: Fasciclin-like arabinogalactan proteins (FLAs) are a class of plant-specific proteins that contribute to various aspects of plant growth, development, and adaptation. However, these proteins have not yet been identified or characterized in maize. This study conducted bioinformatics and expression analyses of the ZmFLA gene family. RESULTS: Based on the homologous comparison methods, 27 ZmFLAs were identified in maize. They were unevenly distributed across ten maize chromosomes, forming 14 pairs of fragment replication with no tandem duplication, revealing that segmental duplication might be the main driving force of the family expansion. Ka/ks analysis of duplicated genes indicating ZmFLAs may undergoing both positively selected and purification selection in evolutionary history. Homologous evolutionary analysis classified 109 FLAs from maize (27 ZmFLAs), rice (27 OsFLAs), wheat (34 TaFLAs), and Arabidopsis (21 AtFLAs) into three groups. The gene structure and protein domain of the ZmFLAs in the same subfamily were highly conserved. The promoter regions of many ZmFLA family members comprised light-, plant growth/hormone-, and abiotic stress-responsive elements. RNA-seq data revealed that the expression pattern of ZmFLAs exhibited organizational specificity and could be influenced by heat, cold, drought, UV, and salt stresses. RT-qPCR of ten ZmFLAs (ZmFLA1/4/5/9/11/16/19/23/25/27) showed that they were either positively or negatively regulated by drought and salt stresses. These findings suggested that ZmFLAs might be involved in the maize response to drought and salt stresses. CONCLUSION: Taken together, the comprehensive analysis of ZmFLAs in the whole genome provides a novel perspective on the evolutionary relationship among maize FLA genes and lays a foundation for further analysis of the biological functions of ZmFLAs.