Characterization of KNOX genes in Medicago truncatula.
We isolated three class I and three class II KNOX genes in Medicago truncatula. The predicted amino acid sequences suggested a possible orthology to the Arabidopsis homeodomain proteins STM, KNAT1/BP, KNAT3 and KNAT7 that was confirmed by phylogenetic and conserved structural domain analyses. Moreover, the STM-like MtKNOX1 and MtKNOX6 proteins were shown to retain the capability to interact with the Arabidopsis BELL protein partners of STM and KNAT1/BP. Amino acid residues that characterize the different classes of KNOX proteins were identified. Gene expression studies revealed organ-specificity, possible cytokinin-dependent transcriptional activation of two MtKNOXs and expression of one STM-like and a BP/KNAT1-like MtKNOX in roots. Interestingly, mRNA localization studies carried out on class I MtKNOX genes revealed important differences with previously characterised legume KNOXs. M. truncatula transcripts were not down-regulated in leaf primordia and early stages of leaf development, features shared with the more distant compound-leaved species Solanum lycopersicum.
Di Giacomo
Elisabetta
E
Institute of Biology and Agricultural Biotechnology, Operative Unit of Rome, Consiglio Nazionale delle Ricerche, Via Salaria Km. 29,300, Monterotondo Scalo, Roma, Italy.
Sestili
Francesco
F
Iannelli
Maria Adelaide
MA
Testone
Giulio
G
Mariotti
Domenico
D
Frugis
Giovanna
G
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003583:Cytokinins / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005875:Gibberellins / Q000494:pharmacology; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D046913:Medicago truncatula / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D018519:Meristem / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D016415:Sequence Alignment; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D003583:Cytokinins; D005875:Gibberellins; D018398:Homeodomain Proteins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012333:RNA, Messenger; D014157:Transcription Factors