Se. Perry et al., THE MADS DOMAIN PROTEIN AGL15 LOCALIZES TO THE NUCLEUS DURING EARLY STAGES OF SEED DEVELOPMENT, The Plant cell, 8(11), 1996, pp. 1977-1989
Little is known about regulatory factors that act during the earliest
stages of plant embryogenesis. The MADS domain protein AGL15 (for AGAM
OUS-like) is expressed preferentially during embryogenesis and accumul
ates during early seed development in monocotyledonous and dicotyledon
ous flowering plants. AGL15-specific antibodies and immunohistochemist
ry were used to demonstrate that AGL15 accumulates before fertilizatio
n in the cytoplasm in the cells of the egg apparatus and moves into th
e nucleus during early stages of development in the suspensor, embryo,
and endosperm. Relatively high levels of AGL15 are present in the nuc
lei during embryo morphogenesis and until the seeds start to dry in Br
assica, maize, and Arabidopsis. AGL15 is associated with the chromosom
es during mitosis, and gel mobility shift assays were used to demonstr
ate that AGL15 binds DNA in a sequence-specific manner. To assess whet
her AGL15 is likely to play a role in specifying the seed or embryonic
phase of development, AGL15 accumulation was examined in Arabidopsis
mutants that prematurely exit embryogenesis. lec1-2 mutants show an em
bryo-specific loss of AGL15 at the transition stage, suggesting that A
GL15 interacts with regulators in the leafy cotyledons pathway.