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United States Department of Agriculture

Agricultural Research Service

2007 Annual Report

1a.Objectives (from AD-416)
Identify effects of atmospheric CO2, solar radiation, temperature and/or soil moisture on putative phytonutrients in crops; assess implications of environmental stress, weather, and global change on crop nutritional value; develop improved methods to measure the content of phytonutrients and their breakdown or metabolic products.

1b.Approach (from AD-416)
Interactions between atmospheric CO2 and other environmental parameters will be investigated in controlled environments (growth chambers and greenhouses), raising crops to seed while regulating and monitoring atmospheric CO2, temperature, soil moisture and nutrition, and photosynthetically- as well as photomorphogenetically-active radiation. Growth chambers will simulate natural conditions. In addition, crops will be raised in the field; environmental conditions at various developmental stages will monitored and compared to those in controlled environments. In some cases, atmospheric CO2 will be regulated in the field (FACE, Free-Air CO2 Enrichment). Work will concentrate on soybeans, rice and peanuts. Seeds will be harvested and analyzed by HPLC for important biologically-active constituents, such as flavonoids, tocopherols, tocotrienols, sterols, saponins, and/or phylloquinone. Effects of environment on biosynthetic pathways will be evaluated.

Elevated atmospheric carbon dioxide does not prevent the effect of short-term elevated temperature on vitamin E metabolism in soybean seeds. Soybean seed composition is altered by prolonged warm temperature during seed development, but plants raised in elevated atmospheric carbon dioxide at concentrations expected by the end of this century are less affected by temperature. Since long-term exposure to high temperature may not be a realistic simulation of current weather or projected future climate patterns, soybeans were exposed to simulated heat spells (one week of moderately elevated temperature) midway during seed development. The effect of this treatment on vitamin E metabolism was qualitatively similar, albeit quantitatively smaller, to that produced by long-term warming, but the short-term treatment was not affected by growing plants at elevated carbon dioxide. These experiments indicate that brief environmental stress can affect soybean seed composition and that rising atmospheric carbon dioxide may not always protect plants from stress.

This research addresses National Program 204, Global Change Component III, Agricultural Ecosystems, focusing on the Cropping Systems Problem Area, as well as National Program 107, Human Nutrition Component 5, Health Promoting Properties of Plants and Animal Foods.

6.Technology Transfer

Number of non-peer reviewed presentations and proceedings2
Number of newspaper articles and other presentations for non-science audiences2

Last Modified: 12/18/2014
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