Proteomic analysis of blue light-induced twining response
in Cuscuta australis
Received: 25 November 2008 / Accepted: 12 October 2009 / Published online: 30 October 2009
Ó Springer Science+Business Media B.V. 2009
Abstract The parasitic plant Cuscuta australis (dodder)
invades a variety of species by entwining the stem and
leaves of a host and developing haustoria. The twining
response prior to haustoria formation is regarded as the ﬁrst
sign for dodders to parasitize host plants, and thus has been
the focus of studies on the host-parasite interaction. How-
ever, the molecular mechanism is still poorly understood.
In the present work, we have investigated the different
effects of blue and white light on the twining response, and
identiﬁed a set of proteins that were differentially expres-
sed in dodder seedlings using a proteomic approach.
Approximately 1,800 protein spots were detected on each
2-D gel, and 47 spots with increased or decreased protein
levels were selected and analyzed with MALDI-TOF-MS.
Peptide mass ﬁngerprints (PMFs) obtained for these spots
were used for protein identiﬁcation through cross-species
database searches. The results suggest that the blue light-
induced twining response in dodder seedlings may be
mediated by proteins involved in light signal transduction,
cell wall degradation, cell structure, and metabolism.
Keywords Dodder Á Twining response Á Host-parasite
interaction Á Differentially expressed proteins Á Proteomics
Dodder (Cuscuta spp.) is a holoparasitic higher plant in the
family of Convolvulaceae. It is comprised of twining stems
without roots and leaves. Although some species have a
small amount of chlorophyll, they have little or no photo-
synthetic activity (van der Kooij et al. 2000). Therefore,
dodders depend on host plants for survival through entwining
the stem or leaves of the hosts and developing haustoria to
obtain nutrition. Since dodder seedlings are self-sufﬁcient
only for about 2–3 weeks, early detection of and attachment
to potential host is essential for survival. The occurrence of
twining followed by haustoria formation is regarded as the
sign for dodders to successfully parasitize hosts, and thus has
been the focus of studies on the host-parasite interaction. The
fact that dodders can invade such a large range of species
indicates that they should have highly adaptable mechanisms
for host attachment. However, the nature of the mechanisms
is still poorly understood.
It is implied in a few studies (Hu and Kong 2003; Kelly
1992) that dodders can perceive host location by
responding to some uncharacterized chemical signals.
However, these chemical signals may be used only by
certain species of root parasites, and it is still unknown
whether stem parasites such as dodders require such
chemical signals for parasitism. Many other studies suggest
that light qualities and duration are the major signals for
inducing the twining response and haustoria formation in
dodders (Lane and Kasperbauer 1965; Furuhashi et al.
1995; Tada et al. 1996; Orr et al. 1996; Haidar 2003). It has
been shown that dodder seedlings tend to grow toward light
sources with low red/far red (R/FR) ratio. This tendency of
growth may help dodders ﬁnd their host plants. In addition,
far red and blue lights may be involved in the twining
response and haustoria formation.
Electronic supplementary material The online version of this
article (doi:10.1007/s11103-009-9562-2) contains supplementary
material, which is available to authorized users.
D. Li Á X. Yang Á G. Zhang Á L. Chen (&)
School of Life Science, Xiamen University, 361005 Xiamen,
Department of Genetics & Biochemistry, Clemson University,
Clemson, SC 29634, USA
Plant Mol Biol (2010) 72:205–213