Figure 1

The development of ovule integuments in Arabidopsis. (A) Two inner and one outer integument grow out from the chalaza (c) during early ovule development. (B) Ovule at stage of fertilization: Integuments have grown around nucellus (n), i.i.1: inner (adaxial) layer of inner integument, i.i.2: outer (abaxial) layer of inner integument, o.i.1: inner (adaxial) layer of outer integument, o.i.2: outer (abaxial) layer of outer integument.