Genome-wide identification and characterization of cytokinin oxidase/dehydrogenase family genes in Medicago truncatula

Cytokinin oxidase/dehydrogenases (CKXs) play a key role in the irreversible degradation of phytohormone cytokinin that is necessary for various plant growth and development processes. However, thus far, detailed investigations CKX gene family model legume Medicago truncatula are limited. In this study, we identified 9 putative homologues with conserved FAD- cytokinin-binding domains M. genome. We analyzed their phylogenetic relationship, structure, domain, expression pattern, protein subcellular locations other properties. The tissue-specific profiles MtCKX genes different among members these MtCKXs also displayed patterns response to synthetic 6-benzylaminopurine (6-BA) indole-3-acetic acid (IAA), suggesting diverse roles development. To further understand biological function MtCKXs, characterized mutants each by taking advantage Tnt1 mutant population truncatula. Results indicated plants harboring insertions single showed no morphological changes aerial parts, functional redundancy shoot disruption Medtr4g126160, which predominantly expressed roots, leads an obvious reduced primary root length increased lateral number, indicating specific regulating architecture. systematically at genome-wide level revealed possible development, shed lights on understanding related plants.