Download Figure 1. - York College of Pennsylvania

PROJECT SUMMARY
This study will determine the relationship between
roadside car pollution, and a tomato crop’s natural
defenses against a predator. Although endogenous
substances are known to affect gene expression, the
role of exogenous substances are relatively unknown.
The chemical to be studied is pin II, a proteinase
inhibitor, that is produced by plants upon attack. When
ingested by insects, it will block the insect’s ability to
break down proteins. The experiment will use a tomato
field that is at the intersection of two roadways. Plants
will be damaged with tobacco hornworms and pin II
activity will be measured after 24 hours. Throughout
the growing season, pollutant levels will be measured.
A bioassay will also be conducted to see if tobacco
hornworms are affected by the various levels of pin II.
The results will yield a correlation between pollutants
and concentration of pin II produced. Results of this
research will establish a relationship between proximity
to roadside pollution & damage to crops by insect
pests.
The Effect of Car Pollutants on the Expression of the
Pin II Gene in Tomato Plants.
Daniel Kani
York College of P.A. Dept of Biological Sciences
•Atmospheric SO2 was found to positively effect insect
feeding preference. (Hughes, et al. 1981)
•There is a negative correlation between car pollution and
pin2 expression
•Higher concentrations of atmospheric SO2 and NO2
positively correlated to insect growth and performance.
(Bell, et al. 1984)
•Tobacco Hornworms will prefer to feed upon, and will
thrive on plants that have been exposed to high levels of
car pollution
•Insects seem to prefer roadway plants because of
higher levels of NOx, which the insects are deficient in.
(Port and Thompson 1980)
•Abscisic acid (ABA) and Jasmonic Acid (JA) can initiate
production, (therefore are part of the pathway). (PenaCortes et al. 1995) (Fig 1)
•Electrical current will also cause pin II production.
(Pena-Cortes et al. 1995 & Davies and Stankovic 1996)
•Oligogalacturonides (pathogen), and chitosan (cell
walls of fungus) will start the pathway. (Doares, et al
1995) (Fig. 1)
Figure 1.
INTRODUCTION
Mechanical Damage
•Proteinase Inhibitor Two (pin II) blocks an insect’s
ability to break down proteins they have ingested, thus
making the plant an undesirable food source
•We know that endogenous substances, such as,
abscisic acid, and jasmonic acid will effect pin II
expression, but we know very little about exogenous
substances
•It is known that certain car pollutants will increases a
plant’s susceptibility to insect attack
•In order for pin II to be produced, the plant must go
through a pathway to reach actual expression of pin II. If
one or more steps are interrupted, pin II will not be
produced
Pathogen Damage
Oligosaccharide
fragments generated
by cell walls.
Protein Systemin is
released by the cells.
RESEARCH DESIGN AND
METHODS
•A tomato plant field, after a full growing season, will be
split up into sectors, and random plants will be damaged
by a tobacco hornworm. Plant samples will be collected
after 24 hours, and frozen in liquid nitrogen (Figure 2)
Systemin or O.S. fragments
activate Lipases
•Each plant sample will then be analyzed, first with RNA
isolation, followed by PCR, to isolate and amplify the
desired gene
•Separate from this experiment, plant samples will be fed
to 2nd instar tobacco hornworms. Feeding habits, as well
as weight gain will be measured. A sample size of 10 will
be used for each plant sample from each sector
Figure 2
•Plants will show a lower density of pin II in sectors
where pollutant levels are higher
•Tobacco hornworms will prefer plants with lower levels
of pin2, and higher levels of pollutants
LITERATURE CITED
Bell, J. N. B., Dohmen, S., and McNeill, S., 1984. Air pollution increases
Aphis fabae pest potential. Nature 307: 52-53
Doares, S.H., Syrovets, T., Weiler, E.W., and Ryan, C.A. 1995.
Oligogalacturonides and chitosan activate plant defensive genes through
the octadecanoid pathway. Proceedings of the National Academy of
Sciences USA 92: 4095-4098.
Hughes, P.R., Potter, J.E., and Weinstein, L.H. 1981. Effects of air
pollutants on plant-insect interactions: reactions of the mexican bean
beetle to SO2-fumigated pinto beans. Environmental Entomology 10: 741744.
Peña-Cortés, H., Fisahn, J., and Willimitzer, L. 1995. Signals involved in
wound-induced proteinase inhibitor II gene expression in tomato and
potato plants. Proceedings of the National Academy of Sciences USA 92:
4106-4113.
Figure 1
Lipases cause Linoleic
acid to be generated and
released by cell
membranes
EXPECTED RESULTS
•During the growing season, the pollutants CO, NO, and
NO2, will be measured weekly in each sector, using gas
analysis tubes
•Then each sample will be placed on a electrophoresis
gel, and banding patterns will be measured by computer,
giving a density of each band
Pin2 Pathway
•Plants use many natural chemicals to protect
themselves against attack
HYPOTHESIS
REVIEW OF LITERATURE
Abscisic acid
(positive regulator)
Port, G.R., and Thompson, J.R. 1980. Outbreaks of insect herbivores on
plants along motorways in the united kingdom. Journal of Applied Ecology
17: 649-656.
R
O
A
D
Linoleic Acid is
converted to Jasmonic
Acid
ROAD
Acknowledgements
Key
Symbol
Jasmonic Acid associates
with 5’ end of DNA,
where transcription of Pin2
gene occurs
Figure 1. Flowchart showing all the steps leading up to pin II
production, from attack, to expression. (Pena-Cortes et al. 1995)
Sector #
Symbol
Sector #
Karl Kleiner, PhD, YCP Research Mentor
1
6
2
7
3
8
4
9
5
10
Figure 2. This is a pictorial map of the tomato field I will be studying. Each
symbol is representative of a different sector.
Bradley Rehnberg, PhD
Jeffery Thompson, PhD