vanishing tassel2 encodes a grass-specific tryptophan aminotransferase required for vegetative and reproductive development in XXXX .

@entity45491 @entity2829 @entity7300 @entity958 @entity72832 @entity72700
Auxin plays a fundamental role in organogenesis in plants. Multiple pathways for auxin biosynthesis have been proposed, but none of the predicted pathways are completely understood. Here, we report the positional cloning and characterization of the vanishing tassel2 (vt2) gene of @entity2829 ( @entity2829 ). Phylogenetic analyses indicate that vt2 is a co-ortholog of TRYPTOPHAN AMINOTRANSFERASE OF @entity958 1 ( @entity72700 ), which converts Trp to @entity45491 in one of four hypothesized Trp-dependent auxin biosynthesis pathways. Unlike single mutations in @entity72700 , which cause subtle morphological phenotypes in @entity958 , vt2 mutants have dramatic effects on vegetative and reproductive development. vt2 mutants share many similarities with sparse inflorescence1 ( @entity72832 ) mutants in @entity2829 . @entity72832 is proposed to encode an enzyme in the @entity7300 pathway for Trp-dependent auxin biosynthesis, although this biochemical activity has recently been questioned. Surprisingly, @entity72832 vt2 double mutants had only a slightly more severe phenotype than vt2 single mutants. Furthermore, both @entity72832 and vt2 single mutants exhibited a reduction in free auxin levels, but the @entity72832 vt2 double mutants did not have a further reduction compared with vt2 single mutants. Therefore, both @entity72832 and vt2 function in auxin biosynthesis in @entity2829 , possibly in the same pathway rather than independently as previously proposed.
