Disease relevance of KNAT1

• Transgenic Arabidopsis plants carrying the KNAT1 cDNA and the kn1 cDNA fused to the cauliflower mosaic virus 35S promoter were generated [1].

High impact information on KNAT1

• The knotted1-like homeobox gene BREVIPEDICELLUS regulates cell differentiation by modulating metabolic pathways [2].
• The Putative RNA-dependent RNA polymerase RDR6 acts synergistically with ASYMMETRIC LEAVES1 and 2 to repress BREVIPEDICELLUS and MicroRNA165/166 in Arabidopsis leaf development [3].
• The abnormal leaf morphology of the double mutants was accompanied by an extended ectopic expression of a class I KNOX gene BREVIPEDICELLUS (BP) and high levels of microRNA165/166 that may lead to mRNA degradation of genes in the class III HD-ZIP family [3].
• PNY is expressed in inflorescence and floral meristems and overlaps with BP in a discrete domain of the inflorescence meristem where we propose the internode is patterned [4].
• Map-based cloning and complementation studies revealed that a null mutation in the KNAT1 homeobox gene is responsible for these pleiotropic phenotypes [5].

Biological context of KNAT1

• In the shoot apex, KNAT1 transcript is localized primarily to the shoot apical meristem; down-regulation of expression occurs as leaf primordia are initiated [1].
• The expression pattern of KNAT1 in the shoot meristem combined with the results of transgenic overexpression experiments supports the hypothesis that class 1 kn1-like genes play a role in morphogenesis [1].
• Misexpression of the knox genes, KNAT1 or KNAT2, in Arabidopsis produces a variety of phenotypes, including lobed leaves and ectopic stipules and meristems in the sinus, the region between lobes [6].
• The steady state transcript levels of the histidine kinase CKI1 gene and the KNAT1 and STM homeobox genes were increased in tsd mutants, while mRNA levels of cell cycle genes were not altered [7].
• In addition, bp plants displayed defects in cell differentiation and radial growth of the style [8].

Anatomical context of KNAT1

• We have used a second-site suppressor screen to isolate mutations in KNAT1 and we show that KNAT1 is partially redundant with STM in regulating stem cell function [9].

Associations of KNAT1 with chemical compounds

• Intron positions are also fairly well conserved among KNAT1, KNAT2, and kn1 [1].
• DEX-induced plants were similar to plants overexpressing the closely related KNAT1 gene, indicating overlapping functions, although we observed differences as well [10].
• Increased steady state mRNA levels of the STM and KNAT1 homeobox genes in cytokinin overproducing Arabidopsis thaliana indicate a role for cytokinins in the shoot apical meristem [11].
• ASYMMETRIC LEAVES1 and auxin activities converge to repress BREVIPEDICELLUS expression and promote leaf development in Arabidopsis [12].
• Cyanobacterial non-mevalonate pathway: (E)-4-hydroxy-3-methylbut-2-enyl diphosphate synthase interacts with ferredoxin in Thermosynechococcus elongatus BP-1 [13].

Regulatory relationships of KNAT1

• Here, we show that auxin and AS1 pathways converge to repress expression of the KNOX gene BREVIPEDICELLUS (BP) and thus promote leaf fate [12].

Other interactions of KNAT1

• The physical association of the PNY and BP proteins suggests that they participate in a complex that regulates early patterning events in the inflorescence meristem [4].
• Analysis by the reverse transcription-polymerase chain reaction showed that transcripts of the KNAT1, KNAT2 and KNAT6 (a recently identified member of the class 1 knox family) genes accumulated in the leaves of both as2 and as1 plants but not of wild type [14].
• Interaction is mediated by BEL1 sequences N terminal to the homeodomain and KNAT sequences including the MEINOX domain [15].
• Domain exchanges between KNAT3 and KNAT1 suggest specificity of the kn1-like homeodomains requires sequences outside of the third helix and N-terminal arm of the homeodomain [16].
• KNAT1 and ERECTA regulate inflorescence architecture in Arabidopsis [5].

Analytical, diagnostic and therapeutic context of KNAT1

• Based on in situ hybridization analysis, the expression pattern of KNAT1 during vegetative development is similar to that of class 1 maize genes [1].

References