Vicia faba TEOSINTE BRANCHED1/CYCLOIDEA/PCF Transcription Factors VfTCP19, VfTCP21 and VfTCP23 Contribute to Biotic and Abiotic Stress-Associated Responses

Abstract Faba bean provides food and feed, also improves field soil. However, its sustainable production is severely constrained by adverse environmental conditions. Identification desired genes could provide resources for resistance breeding, thus improve field performance. Here, 24 VfTCP transcription factors were identified and characterized as nucleus-localized, unstable, hydrophilic proteins. VfTCPs were under strong purifying selection, and their promoters contained cis-elements related to growth, development, and stress responses. Transcriptome profiling and RT-qPCR confirmed their stress-responsive expression patterns. Experimental analyses confirmed the nuclear localization and GAL4-based transcriptional activation activity of VfTCP19/21/23. Transient overexpression of VfTCP19/21/23 contributed to pathogen resistance by maintaining ROS homeostasis and attenuating BAX-, NIP-, and INF1-induced. Meanwhile, they enhanced drought and salt tolerance by regulating stomatal aperture, strengthening water retention, improving water status, and scavenging ROS, thereby alleviating leaf wilting. These findings revealed VfTCP19/21/23 as potential candidate genes for future stress-resistance breeding.