Expression of the quinoa TCP gene family and analysis of CqTCP11 involvement in seed germination stress response

The TCP transcription factor family is a key regulator of plant growth, development and stress adaptation. The TCP gene family in the stress-tolerant cereal Chenopodium quinoa has not been systematically characterized. In this study, 20 non-redundant CqTCP members were identified genome-wide in quinoa and classified into three subfamilies (PCF, CIN and CYC/TB1) based on phylogenetic relationships. CqTCPs possess few introns, and their promoter regions are enriched in various cis-acting elements related to abiotic stress, hormone and light responses. They exhibit tissue-specific expression, and the expression of multiple members is significantly regulated by salt and drought stresses. Functional verification showed that CqTCP11 is localized in the nucleus. Heterologous overexpression of this gene in Arabidopsis thaliana significantly improved seed germination rate under salt and drought stresses, and enhanced the antioxidant capacity and osmotic adjustment ability of seedlings. This study systematically characterized the features of the quinoa TCP family and its functions in stress responses, clarified the key role of CqTCP11 in stress resistance during seed germination, and provided candidate genes and theoretical support for the genetic improvement of stress resistance in quinoa.