Reference "Expression of CDC2Zm and KNOTTED1 during in-vitro axillary shoot meristem proliferation and adventitious shoot meristem formation in maize (Zea mays L.) and barley (Hordeum vulgare L.)"

Reference ID

11130

Title

Expression of CDC2Zm and KNOTTED1 during in-vitro axillary shoot meristem proliferation and adventitious shoot meristem formation in maize (Zea mays L.) and barley (Hordeum vulgare L.)

Source

Planta, 1998, vol. 204, pp. 542-549

Authors (4)

Zhang-S	Williams-Carrier-R
Jackson-D	Lemaux-P-G

Abstract

Expression of CDC2Zm and KNOTTED1 (KN1) in maize (Zea mays L.) and their cross-
reacting proteins in barley (Hordeum vulgare L.) was studied using
immunolocalization during in-vitro axillary shoot meristem proliferation and
adventitious shoot meristem formation. Expression of CDC2Zm, a protein involved
in cell division, roughly correlated with in-vitro cell proliferation and in the
meristematic domes CDC2Zm expression was triggered during in-vitro
proliferation. Analysis of the expression of KN1, a protein necessary for
maintenance of the shoot meristem, showed that KN1 or KN1-homologue(s)
expression was retained in meristematic cells during in-vitro proliferation of
axillary shoot meristems. Multiple adventitious shoot meristems appeared to form
directly from the KN1- or KN1 homologue(s)-expressing meristematic cells in the
invitro proliferating meristematic domes. However, unlike Arabidopsis
(Arabidopsis thaliana) and tobacco (Nicotiana tabacum) leaves ectopically
expressing KN1 (G. Chuck et al., 1996 Plant Cell 8: 1277-1289; N. Sinha et al.,
1993 Genes Dev. 7: 787-797), transgenic maize leaves over-expressing KN1 were
unable to initiate adventitious shoot meristems on their surfaces either in
planta or in vitro. Therefore, expression of KN1 is not the sole triggering
factor responsible for inducing adventitious shoot meristem formation from in-
vitro proliferating axillary shoot meristems in maize. Our results show that
genes critical to cell division and plant development have utility in defining
in-vitro plant morphogenesis at the molecular level and, in combination with
transformation technologies, will be powerful tools in identifying the
fundamental molecular and-or genetic triggering factor(s) responsible for
reprogramming of plant cells during plant morphogenesis in-vitro.