KNAT2 Background Information The KNOTTED class of plant genes encodes homeodomain proteins that show expression patterns suggestive of an important role in shoot meristem function (1). Members of the KNOTTED gene family include KNAT1 and KNAT2 (for knotted-like from Arabidopsis thaliana) and are expressed early in embryogenesis, providing molecular markers for meristem initiation (2,3). KNAT1 is expressed in the shoot apical meristem and not in determinate organs (2,4). Ectopic expression of KNAT1 causes dramatic alterations in Arabidopsis including lobed leaves and ectopic stipules and meristems in the sinus, the region between lobes (3–5). The KNAT2 homeobox gene is expressed in the vegetative apical meristem (6). KNAT2 is also active during flower development, specifically carpel development, suggesting that KNAT2 funtions in the structuring of flowers (6).
