Fasciclin-like arabinogalactan gene family inNicotiana benthamiana: genome-wide identification, classification and expression in response to pathogens

Background Nicotiana benthamianais widely used as a model plant to study plant-pathogen interactions. Fasciclin-like arabinogalactan proteins (FLAs), a subclass of arabinogalactan proteins (AGPs), participate in mediating plant growth, development and response to abiotic stress. However, the members of FLAs inN. benthamianaand their response to plant pathogens are unknown. Results 38NbFLAswere identified from a genome-wide study.NbFLAscould be divided into four subclasses, and their gene structure and motif composition were conserved in each subclass.NbFLAsmay be regulated by cis-acting elements such as STRE and MBS, and may be the targets of transcription factors like C2H2. Quantitative real time polymerase chain reaction (RT-qPCR) results showed that selectedNbFLAswere differentially expressed in different tissues. All of the selectedNbFLAswere significantly downregulated following infection by turnip mosaic virus (TuMV) and most of them also byPseudomonas syringae pv tomatostrain DC3000 (PstDC3000), suggesting possible roles in response to pathogenic infection. Conclusions This study systematically identifiedFLAsinN. benthamiana, and indicates their potential roles in response to biotic stress. The identification ofNbFLAswill facilitate further studies of their role in plant immunity inN. benthamiana.