Atmospheric chnages on plants

[John Paul Sanborn]

Biomass of Tomato Seedlings Exposed to an Allelopathic Phenolic Acid and Enriched Atmospheric Carbon Dioxide

S. R. Shafer1 Contact Information, U. Blum1, S. J. Horton1 and D. L. Hesterberg1
(1) USDA-ARS Air Quality Program, Dept. of Plant Pathology Dept. of Plant Pathology, Dept. of Soil Science, North Carolina State University, Raleigh, NC 27695, USA

Abstract Increased atmospheric CO2 can affect plant growth, so competition among plants may be influenced. Allelopathy is one mechanism involved in plant competition. Experiments were conducted in a controlled-environment chamber to determine if the concentration of atmospheric CO2 altered the dose-response relationship between an allelopathic phenolic acid and tomato seedling biomass. Seeds of Lycopersicon lycopersicum were planted in quartz sand in styrofoam cups and allowed to germinate and grow for 15–17 days. During the next 14 days, seedlings were watered twice daily with nutrient solution amended with p-coumaric acid (4-hydroxycinnamic acid, HOC6H4CH = CHCO2H; ranging 0–0.85 mg mL-1; 5 concentrations in each experiment) and exposed 24 hr day-1 in continuous-stirred tank reactors (CSTRs) to ambient air (335–375 ppm CO2) or ambient air to which 350 ppm CO2 was added (i.e., approximately twice-ambient CO2; two CSTRs per CO2 concentration in each experiment). Dose-response data relating p-coumaric acid concentration and shoot, root, and total biomass were fit to a flexible decay function. In all three experiments, twice-ambient CO2 significantly increased the y-intercept for the dose-response model for the p-coumaric acid effect on shoot biomass by 25–50% but had negligible effects on other aspects of the models. Results suggest that if CO2 affects plant competition, mechanisms involving allelopathic phenolic acids may not be involved.

http://www.springerlink.com/content/t08r3w1383402618/

 

[Urban Forester]

I would love to see the same test done on an environmentally sensitive tree (i.e. White Birch/Japanese Maple) and on a environmentally vigorous tree (i.e. Katsura/Ginkgo). Which would produce more/less secondary metabolites? Does the production of secondary metabolites create(?) a manipulated environment? Interesting stuff...

 

[John Paul Sanborn]

a manipulated environment? Interesting stuff...

They have shown that higher CO2 makes poison ivey more vigorous and produces more urushiol.

This is an updated version, i first read about it over a year ago.

Research Project: Crop and Weed Responses to Increasing Atmospheric Carbon Dioxide

Location: Crop Systems & Global Change

Title: Rising Carbon Dioxide, Plant Biology Public Health: Potential Impacts on the Growth and Toxicity of Poison Ivy (Toxicodendron radicans)

Authors
Ziska, Lewis
Sicher, Richard
George, Kate - UNIV OF MD
Mohan, Jackie - MAR BIO LAB-WOODS HOLE,MA

Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 1, 2007
Publication Date: July 1, 2007
Citation: Ziska, L.H., Sicher Jr, R.C., George, K., Mohan, J.E. 2007. Rising Carbon Dioxide, Plant Biology Public Health: Potential Impacts on the Growth and Toxicity of Poison Ivy (Toxicodendron radicans). Weed Science. 55:288-292.

Interpretive Summary: Carbon dioxide stimulates the growth of plants, but different types of plants respond differently. Some plants that could respond to carbon dioxide include plants that affect people's health. For example, poison ivy can induce a skin rash in two out of three people who come into contact with it for the first time. In this experiment we examined how poison ivy could respond to increases in carbon dioxide using concentrations of carbon dioxide that existed in 1950, the current level of carbon dioxide, and the projected level of carbon dioxide for the years 2050 and 2090, respectively. We found that carbon dioxide stimulated the growth of poison ivy with the largest relative increase occurring between 1950 and today. In addition, we found that as carbon dioxide increased, the production of urushiol, the oil in poison ivy that causes a rash, increased as well. Overall, these results indicate that the growth and survivability of poison ivy is likely to increase as carbon dioxide increases in the atmosphere. These data will be of interest to climatologists, health care providers, pharmaceutical companies, scientists, and policy makers.

Technical Abstract: Because of its ability to induce contact dermatitis, the establishment and spread of poison ivy (Toxicodendron radicans (L.) Kuntze) is recognized as a significant public health concern. In the current study, we quantified potential changes in the biomass and urushiol content of poison ivy as a function of incremental changes in global atmospheric carbon dioxide concentration [CO2]. We also examined the rate of new leaf development following leaf removal to simulate responses to herbivory as functions of both [CO2] and plant size. The experimental CO2 values (300, 400, 500 and 600 umol mol-1) corresponded approximately to the concentration that existed during the middle of the 20th century, the current concentration, and near and long-term projections for this century (2050 and 2090), respectively. Over a 250-day period, increasing [CO2] resulted in significant increases in leaf area, leaf and stem weight, and rhizome length relative to the 300 umol mol-1 baseline, with the greatest relative increase occurring from 300 to 400 umol mol-1. Because of the stimulatory effect of [CO2] on leaf biomass, the amount of urushiol produced per plant increased significantly for all [CO2] above the 300 umol mol-1 baseline. Significant increases in the rate of leaf development following leaf removal were also observed with increasing [CO2]. Overall, these data confirm earlier, field-based reports on the CO2 sensitivity of poison ivy, but emphasize its ability to respond to even small (ca 100 umol mol-1) changes in [CO2] above the mid 20th century carbon dioxide baseline. This would suggest that its rate of spread, its ability to recover from herbivory, and its production of urushiol, may be enhanced in a future, higher CO2 environment.

Project Team
Bunce, James
Sicher, Richard
Ziska, Lewis



Related National Programs
Global Change (204)
Plant Biological and Molecular Processes (302)
Air Quality (203)
Related Projects
Soil Carbon in Urban Environments
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Last Modified: 07/19/2009

Here is a search from that site for CO2 maple

http://pubsearch.arsnet.usda.gov/se...frontend&proxystylesheet=ars_frontend&lr=&oe=

 

[Ed Roland]

"Ambient CO2 level in outside air is about 340 ppm by volume. All plants grow well at this level but as CO2 levels are raised by 1,000 ppm photosynthesis increases proportionately resulting in more sugars and carbohydrates available for plant growth." -T.J Blom; W.A. Straver; F.J. Ingratta; Shalin Khosla - OMAF; Wayne Brown

Your data suggesting the allelopathic qualities of plants are not enhanced when all other processes are when introduced to high concentrations of co2 is interesting. Stress that same plant and data would suggest allelopathic production decreases.

Trees are mysterious.

 

[John Paul Sanborn]

Trees are mysterious.

And fascinating.