Primordia

Primordium initiation

Primordia initiation is the precursor for the start of a primordium, and typically confers new growth (either flowers or leaves) in plants once fully mature. In pines, the leaf primordia develop into buds, which eventually elongate into shoots, then stems, then branches. Though primordia are typically only found in new flower and leaf growth, root primordia in plants can also be found, but are typically referred to as lateral root primordium or adventitious roots. The process of lateral root primordium initiation has been studied in Arabidopsis thaliana, though the process in other angiosperms is still under analysis. Primordia are initiated by local cell division and enlargement on the shoot apical meristem. At least in wheat plants, leaf primordium initiation rates increase with increasing ambient temperature, and the leaf number of some varieties decrease with increasing daylength.