References

6TargetsofSI 89
is crosstalk between the SI signalling cascades and that PCD probably functions
as a decision-making point that results in incompatible pollen being
committed to death.
Thus, we are beginning to dissect a complex network of signals and
targetsinvolvedinsignallingcascadestriggeredbySI.Thechallengefor
the future is not only to identify additional components, but also to elucidate
how these components interact and what crosstalk is utilized during
SI. In particular, the specific molecular interactions between [Ca 2+ ]i,actin
alterationsandPCDsignallingcascadesarecurrentlybeinginvestigated.
Furthermore, hints that p56 MAP kinase activation may also cross-talk to
these elements are being pursued, as there is evidence for MAPK involvement
in F-actin alterations and PCD in other systems (Zhang et al. 2000;
Yang et al. 2001; Samaj et al. 2002). As the title of this book implies, it
appears that plants have some aspects of a neuronal-like system of communication
and we are just beginning to scratch the surface of understanding
the intricacies of how cellular responses are achieved through networks of
signalling intermediates.
Acknowledgements. Research in the laboratory of V.E.F.-T. is supported
by Biotechnology and Biological Sciences Research Council (BBSRC). Research
in the laboratory of C.J.S. is supported by the US Department of
Agriculture, National Research Initiative grant no. 2002–35304–12412, and
by the US Department of Energy – Energy Biosciences Division grant DE-
FG02-04ER15526.
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