The repression of KNOXI genes by ARP genes in the site of leaf initiation is a pre-requisite for the acquisition of determinacy in the leaf primordium
(reviewed in Hay & Tsiantis, 2010).
Thus colleter secretion products on the abaxial side are secreted into the space between the stipules where there is a leaf primordium
to protect it.
Cytohistological zonation similar to the mature vegetative apex occurs at the time the first leaf primordium
is being initiated.
Comparative leaf developmental studies showed that the two leaf types differed soon after their inception and that accelerated (length) development in the "juvenile" leaf primordium
was probably responsible for its derivation from the "adult" type of leaf (Clearwater & Gould, 1993).
Wheat apical development consists of three distinct phases: leaf primordium, spikelet primordium, and floret primordium initiation.
the duration of leaf primordium initiation was restricted to 126 ATU for MS; to 138 ATU for T0 and T1, which appeared simultaneously; to 180 ATU for T2; and to 225 ATU for T3, T10 and T11, which appeared simultaneously.
As far as is known in mimosoid legumes, at least one bud is formed at every node concomitant with, or slightly after, formation of the leaf primordium.
In some taxa the leaf primordia and inflorescence primordia form at the same time, but development of the leaf primordium is delayed (but not suppressed) relative to the subtended unit inflores cence.
Five Arachis hybrids provided healthy apical meristems (meristem with zero or one leaf primordium
from micropropagated nodal explants.
The uppermost or anodic portion of the bifurcated primordium becomes a stolon complex (similar to that described for Stratio tes), while the other, cathodic portion of the primordium bifurcates again, forming the stolon in the middle and another stolon complex in the position farthest from the next youngest leaf primordium
A more subtle disagreement concerns the nature of the earliest stage of leaf development and the related question of the boundary between foliar and cauline tissues at the base of the leaf primordium
Until to 30 days culture, the seeds initiated to grow light green leaf primordiums
and shoot tips on the apex, while the body began to present greenish or yellowish-white.