thaliana simple leaf (A) with small marginal protrusions called serrations (red asterisk) a C. Mapping of RCO and complementation of the rcomutant. If such genes exist, then loss of their function might prevent leaflet formation without perturbing meristem function.įig. To determine whether leaflet-specific factors exist, we conducted a genetic screen in Cardamine hirsuta, a dissected-leaf relative of the simple-leaf reference plant Arabidopsis thaliana ( Fig. This view is also consistent with the evolutionary origin of leaves from branched shoots ( 5). Rather, a key factor in leaflet formation is the reactivation of meristem genes in leaves, which suggests that evolutionary differences in leaf complexity arose through modification of activity of genes that influence meristem function (4). So far, no gene has been identified that expresses specifically at developing leaflets and is sufficient to convert a simple leaf into a more complex one. However, in dissected leaves, elaboration of lateral growth axes after leaf initiation generates leaflets ( 2, 3). Both simple and dissected leaves initiate as entire structures at the flanks of the pluripotent shoot apical meristem ( 1). In this work, we investigate this problem in the case of angiosperm leaves. Understanding how form evolves requires identifying the genetic changes underlying morphological variation between species and elucidating how those changes influence morphogenesis.
0 kommentar(er)
