Genome-Wide Analysis of the TCP Gene Family in Switchgrass ( Panicum virgatum L.).

The plant-specific transcription factor TCPs play multiple roles in plant growth, development, and stress responses. However, a genome-wide analysis of TCP proteins and their roles in salt stress has not been declared in switchgrass ( Panicum virgatum L.). In this study, 42 PvTCP genes ( PvTCPs ) were identified from the switchgrass genome and 38 members can be anchored to its chromosomes unevenly. Nine PvTCPs were predicted to be microRNA319 ( miR319 ) targets. Furthermore, PvTCPs can be divided into three clades according to the phylogeny and conserved domains. Members in the same clade have the similar gene structure and motif localization. Although all PvTCPs were expressed in tested tissues, their expression profiles were different under normal condition. The specific expression may indicate their different roles in plant growth and development. In addition, approximately 20 cis -acting elements were detected in the promoters of PvTCPs , and 40% were related to stress response. Moreover, the expression profiles of PvTCPs under salt stress were also analyzed and 29 PvTCPs were regulated after NaCl treatment. Taken together, the PvTCP gene family was analyzed at a genome-wide level and their possible functions in salt stress, which lay the basis for further functional analysis of PvTCPs in switchgrass.