The Effects of Phytohormones on Brassica rapa in an Artificial
System
Daniel Holoubek
York College of Pennsylvania Department of Biological Sciences
Project Summary
The proposed project deals with a groundbreaking method of
cultivating plants in a completely enclosed artificial environment. The
Closed plant production system is a useful tool that has been used for
commercial plant production since the 1980s in Japan. The purpose of
this project deals with the improvement of the current process using
the application of phytohormones to promote the growth of
commercial plants, in this case Brassica rapa. Brassica rapa was selected
for its rapid cycling ability (full life cycle approximately 35 days), as
well as its relation to a common commercial grade plant, Brassica
campestris (canola oil producer). The phytohormones selected are
indole acetic acid (IAA), abscisic acid(ABA), and gibberellic acid (GA3)
and these have been seen as the most researched and beneficial
phytohormones. Exploration of ideal concentrations and synergistic
effects of the phytohormones is the key concern of this research in
regards to the possible improvement of the closed plant system. Upon
completion of the proposed experiment, it is believed that through the
administration of low levels (0.1, 1.0 mg/L) of phytohormones, the
combination of IAA and GA3 will produce the best results in regards
to growth and dry biomass.
Introduction
•A closed plant production system (closed system) consists of a
completely self contained environment for cultivation of plants. Countries
such as Japan have been utilizing such systems for commercial cultivation
since the mid-1980s. (Kozai 2007)
•Closed plant production systems have several advantages over open
plant production systems (nursery, greenhouse, etc.) such as conformity
of plant size and shape, year-round growth capabilities, minimal contact
with outside environment, and excellent utilization of resources (Ohyama
et al., 2000)
•The utilization of closed systems is believed to be a possible method of
solving the global trilemma: shortage of food & feed, shortage of natural
resources, and shortage of phytomass (Kozai et al., 2000)
•There exist numerous studies exploring the affects of various
phytohormones on different aspects of plants growth but there is little to
no evidence on the effects of phytohormones in a closed system
Figure 1. These graphs represent expected height results. They are
Based upon the literature and are expected to be interchangeable results
with the total weights accumulated. It is believed that height and weight will be
sufficient indicators of the success of the experiment at this stage in the research. The
success is believed to be concentration related and less hormone is believed to produce
greater growth.
Objectives
Methods Overview
•Understand the possible role of phytohormones in
closed production systems
•Develop methods which could be applied to a larger
group of commercially cultivated plants
•Better understand the effects of phytohormone
combination reactions
Review of Literature
Expected Results
In regards to results from the literature, it is believed
that the smallest doses of phytohormone (0.1 and 1
mg/L) will produce the best results. It is also
expected that the plants treated with both IAA and
GA3 will produce the largest plants in regards to
height and dry weight
Closed System Construction
Hormone
treatments
Abscisic acid
(ABA)
(Kozai 2007)
•Introduction into the positive aspects of utilizing the
closed system both to the environment as well as
economic positives
•Comparisons of open and closed plant systems and how
closed systems are the way of the future
•Discusses benefits of transplant applications
(Pedroza-Manrique and Fernandez-Lizarazo 2005)
•Focus on broad range phytohormone treatments
•Results measure growth and secondary metabolism
along with synergistic effects of phytohormones
(Hisamatsu et. al., 2000)
•Discusses the natural levels of hormones and how biotic
and abiotic factors may affect the subsequent production
of the hormones
Gibberelic acid
(GA3)
Indole Acetic Acid
(IAA)
Possible Issues
ABA+GA3
IAA+ABA
35 day cycles
Phytohormone Conc.
Control (0), 0.1, 1, 10, 100
Self pollination of plants
10,000 seeds sown
IAA+GA3
•Airborne hormone health hazards present possible
risks to the scientists involved
•Hormone cross contamination via evaporation may
provide inaccurate results
•Insufficient/overabundant hormone concentration
may cause overgrowth beyond the point of the plants
support strength
•Genetic anomalies may cause some plants to be
more or less responsive to phytohormone therapy
•Pathogens such as fungi, bacteria and other
microscopic threats could cause contamination and
even devastation of research
Future Research
24 hr light
Daily Hormone adminitstation
Wisconsin Fast plants proc.
100 cell growth beds
4 seeds per cell
Only 1 seedling allowed develop
• Research different plant species that would be acceptable
candidates for commercial cultivation and transplant production
•Evaluate transplant efficacy by planting phytohormone treated
plants in a natural environment
•Establish automated system of hormone administration
•Expand upon range of hormones tested with a focus on various
cytokinins and auxins
Seeds kept in groups
and randomly assigned
to the next generation
(Ohyama et. al., 2000)
•Insight into technological requirements for a closed
system
•Discussion of modern technologies that are key in the
advancement of the clsoed system
(Sun 2008)
•In depth discussion of the Gibberellin pathway in
Arabidopsis and an introduction into how
phytohormones effect plants
Results
Growth measured daily
-height
-diameter
Final Measurement
-height
-weight
Literature Cited
Kozai, Toyoki. 2007. Propagation, grafting and Transplant Production in Closed Systems with Artificial
Lighting for Commercialization in Japan. Propagation of Ornamental Plants 7: 145-149
Sun, T. 2008. Gibberellin Metabolism, Perception and Signaling Pathways in Arabidopsis. The
Arabidopsis Book 1-28
Pedroza-Manrique, J., Fernandez-Lizarazo, C. and Suarez-Silvia, A. 2005 Evaluation of the Effect of
Three Growth Regulators in the Germination of Comparettia Falcata Seeds Under In Vitro Conditions. In
Vitro Cellular and Developmental Biology – Plant 41: 838-843.
Kozai,T. , Ohyama, K., Kubota, C. 1999 Transplant production in Closed Systems with Artificial Lighting
for Solving Global Ussues on Environment Conservation, Food, Resource and Energy Center for
Controlled Environment Agriculture
Hisamatsu T, Koshioka M, Kubota S, Fujime Y, King R, Mander L. The role of gibberellin biosynthesis in
the control of growth and flowering in Matthiola incana. Physiologia Plantarum. May 2000;109(1):97-105
Acknowledgement:
I would like to thank Dr. Bruce Smith for his correspondence, insight
and his tremendous well of knowledge from which he generously shared.
I would also like to thank Dr. Singleton for his guidance and critique.
Abscisic acid (ABA)
Gibberellic acid (GA3)
Indole acetic acid (IAA)