Research
Interests:
Over the past ten years, my research has been focused primarily
in two areas:
(1) the study of cell motility and the
cytoskeleton
and their relations to signal transduction
in plant
cells and
(2) the development of better video imaging
methods.
A long-standing
interest has been the structure of the cytoskeleton (earlier
in relation to the mechanism(s) of cytoplasmic streaming)
and especially the precise localization over time of actin
and microtubules and endoplasmic reticulum in cells. These
structures are very dynamic and are involved in many cell
processes including signal transduction events.
Calcium and
proton ions serve as signals in many other cellular events
and we have available now instrumentation for the precise
detection and quantitation of small changes in Ca++ and
H+ levels in cells using video microscopy and ratio imaging
as well as electrophysiological methods. Several systems
are being investigated.
1. Graviperception. We are investigating how
plant cells perceive gravity and how this signal is transduced
to cause the observed growth responses.
2. Nodulation. We are investigating the early
responses of Medicago to Rhizobium and Nod
factors.
I am the former Director of the Cellular
and Molecular Imaging Facility (CMIF) located in the
Plant BiologyDepartment at NCSU. This facility
houses a number of microscopes including a Leica confocal
laser scanning microscope. I have a long-standing
interest in further improving methods of electronic
light microscopy.
We have developed a new method, Polarization Modulation
DIC and we will continue to further test and develop the
polarization modulation microscope as well as any other
microscope improvements we find necessary in order to
record dynamic events in living cells.
More recently, we have become interested in developing
biosensors in collaboration with Professors in Engineering
and Physics at NCSU. The eventual goal is to develop
very small sensors that can be placed next to or in cells
to measure a number of parameters.
Selected
Publications:
Greg
Nusz, Eva Johannes, Nina Strömgren Allen, Hans D. Hallen.
2006.
Self-Assembled Monolayer Coating of Biological Probes to
avoid Protein Adhesion. NanoBioTechnology. In press.
Gupton SL, Collings DA, Allen NS.
2006. Endoplasmic reticulum targeted GFP
reveals ER organization in tobacco NT-1 cells during cell
division. Plant
Physiol. Biochem. in press.
Moyer-Henry
K, Silva I, Macfall J, Johannes E, Allen NS, Goldfarb B,
Rufty
T. 2005. Accumulation and localization of aluminium in root
tips of loblolly
pine seedlings and the associated ectomycorrhiza Pisolithus
tinctorius.
Plant Cell Environ. 28: 111-120
Vincent P., M. Chua, F. Nogue, A. Fairbrother, H. Mekheel,
Y.Xu, N. Allen,
T. Bibikova, S. Gilroy, V. A. Bankaitis. 2005.A Sec14p-nodulin-domain
phosphatidylinositol transfer protein polarizes membrane
growth of Arabidopsis root hairs. J. Cell Bio. 801-812.
Weerasinghe
R, Bird DM, Allen N.S. 2005. Root-knot nematodes and bacterial
Nod factors elicit common signal transduction events in
Lotus japonicus root hair cells. PNAS 102:2147.
Katherine A. Turner,
Tim L. Sit, Anton S. Callaway, Nina S. Allen, Steven A.
Lommel. 2004. Red Clover Necrotic Mosaic Virus Replication
Proteins Accumulate at the Endoplasmic Reticulum. Virology.
On line.
Ravisha R. Weerasinghe,
David A. Collings, Eva Johannes, Nina Strömgren Allen.
2003. The distributional changes and role of microtubules
in Nod factor challenged Medicago sativa root hairs. Planta
218: 276-287
N.Strömgren
Allen P. Chattaraj, D. Collings, and E. Johannes. 2003.
Gravisensing: Ionic Responses, Cytoskeleton and amyloplast
behavior. Advances in Space Science. Res. 32: 163-167
W.
Pline, KL Edmisten, T Oliver, JW Wilcut, R Wells, NS Allen.
2002. Use of digital image analysis, viability stains, and
germination assays to estimate conventional and glyphosphate-resistant
cotton pollen viability.
Crop
Science 42:2193-2200.Cover photo.
Johannes
E, Collings DA, Rink JC, Allen NS. 2001. Cytoplasmic pH
dynamics in Maize Pulvinal Cells Induced by Gravity Vector
Changes. Plant Phys: 127:119-130.
Johannes, E.; Collings, DA; Rink, JC; Allen, NS. 2001.
Cytoplasmic pH dynamics in Zea mays cells induced by gravity
vector changes. Plant Phys: 127:119-130.
Collings DA, Zsuppan,
G, Allen, NS, Elison B. Blancaflor. 2001. Demonstration
of prominent actin filaments in the root columella. Planta
212:392-403.
Collings DA, Carter,
CN, Rink JC, Scott, AC, Wyatt, SE, Allen, NS.
2000. Plant
Nuclei contain Extensive Cytoplasmic Grooves and Invaginations.
Plant Cell: 12:2425-2440.
Collings, D.A.
and Allen, N.S. (2000) Cortical actin interacts with the
plasma membrane and microtubules.
In: "Actin: A Dynamic Framework For Multiple
Plant Cell Functions." eds Baluska F, Barlow, PW, Staiger
CJ &Volkmann D. Kluwer pp. 145-163.
Silver I, Smyth
TJ, Moxley DF, Carter TE, Allen NS, Rufty, TW. 2000. Aluminum
Accumulation at Nuclei of Cells in the Root Tip: Fluorescence Detection Using Lumogallion and Confocal Laser
Scanning Microscopy.
Plant Phys 123:543-552.
Scott,
A.C., and N.S. Allen.
1999. Changes
in cytosolic pH within Arabidopsis Root Columella Cells
Play a Key Role in the Early Signaling Pathway for Root
Gravitropism. Plant Physiol 121:1291-98.
Scott,
A.C., S. Wyatt, P. Tsou, N. Robertson, and N.S.
Allen. 1999.
A model system for
plant cell biology:
GFP imaging in living onion
epidermal cells.
BioTechniques 26:1125-1132.(with
cover photo voted best cover of 1999).
Nancy L. Jones,
Nina S. Allen, Mark C. Willingham, and Jon C. Lewis.
1999. Modified
LDLs induce and bind to membrane ruffles on macrophages.
The AnatomicalRecord 255:44-56.
Collings,D.A.,
Winter,H., Wyatt,S.E. and Allen,N.S.
1998. Growth
dynamics and cytoskeleton organization during stem maturation
and gravity-induced stem
bending in Zea
mays L. Planta 207:246-258.
Collings,
D.A., Asada,T.A., Allen,N.S and Shibaoka,S.
1998. Plasma
membrane-associated actin in tobacco BY-2 cells: evidence
for interaction with microtubules.
Plant Physiol.118:917-928.
Holzwarth,
G., Webb, S.J., Kubinski, D.J., N.S. Allen.
1997. Improving
DIC Microscopy with Polarization Modulation.
Jour. of Microscopy 188:249-254.
Allen,
R.D. and N.S. Allen. 1983.
Video-enhanced microscopy with a computer frame memory.
Jour. of Microscopy. 129:3-18.
Collings,D.A.,
Winter,H., Wyatt,S.E. and Allen,N.S.
1998. Growth
dynamics and cytoskeleton organization during stem maturation
and gravity-induced stem bending in Zea
mays L. Planta 207:246-258.
Collings,
D.A., Asada,T.A., Allen,N.S and Shibaoka,S.
1998. Plasma
membrane- associated
actin in tobacco BY-2 cells: evidence for interaction with
microtubules.
Plant Physiol.118:917-928.
Allen,
N.S., M.N. Bennett, D.N. Cox, A. Shipley, D.W. Ehrhardt,
S.R. Long. 1994.
Effects of Nod Factors on Alfalfa Root
Hair Ca++
and H+
Currents and on Cytoskeletal Behavior.
In Advances in Molecular Genetics of Plant-Microbe
Interactions. Vol. 3. M.J. Daniels, J.A. Downie, and A.E.
OsBOurn (eds.) Kluwer Academic, Netherlands.
Johannes,
E,Collings, DA, Rink JC, Allen, NS. 2001. Cytoplasmic pH
dynamics in Zea mays pulvinal cells induced by gravity vector
changes. Plant Physiology (In press).
TV
Productions:
NOVA, The
Green Machine. Film footage on cytoplasmic
streaming.
NOVA, Still Waters. Advisor on cine micrography.
Cyanobacteria and stromatolites. 1992. Video tape
as part of museum exhibit. For Chadd-Angiers Production
Co., MA.
Contractility of striated muscle. 1992. Video tape
as part of museum exhibit. For Chadd-Angiers Production
Co. MA.
Many other digital and analogue video sequences and tape
productions of events and structures in living cells are
available upon
request.
