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

Abstract

<jats:title>Abstract</jats:title> <jats:p><jats:bold>Background: </jats:bold><jats:italic>Nicotiana benthamiana</jats:italic> is 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 in <jats:italic>N. benthamiana</jats:italic> and their response to plant pathogens are unknown.<jats:bold>Results: </jats:bold>38 <jats:italic>NbFLAs</jats:italic> were identified from a genome-wide study. <jats:italic>NbFLAs</jats:italic> could be divided into four subclasses, and their gene structure and motif composition were conserved in each subclass. <jats:italic>NbFLAs</jats:italic> may be regulated by cis-acting elements such as STRE and MBS, and could possibly be the targets of transcription factors like C2H2. Quantitative real time polymerase chain reaction (RT-qPCR) results showed that selected <jats:italic>NbFLAs</jats:italic> were differentially expressed in different tissues. All of the selected <jats:italic>NbFLAs</jats:italic> were significantly downregulated following infection by turnip mosaic virus (TuMV) and most of them also by <jats:italic>Pseudomonas syringae pv tomato</jats:italic> (<jats:italic>Pst</jats:italic>) strain DC3000 (<jats:italic>Pst</jats:italic> DC3000), suggesting possible roles in response to pathogenic infection.<jats:bold>Conclusions:</jats:bold> This study systematically identified <jats:italic>FLAs</jats:italic> in <jats:italic>N. benthamiana</jats:italic>, and indicates their potential roles in response to biotic stress. The identification of <jats:italic>NbFLAs</jats:italic> will facilitate further studies of their role in plant immunity in <jats:italic>N. benthamiana.</jats:italic></jats:p>