TY - JOUR
T1 - Amino acids as a nitrogen source for tomato seedlings
T2 - The use of dual-labeled (13C, 15N) glycine to test for direct uptake by tomato seedlings
AU - Ge, Tida
AU - Song, Shiwei
AU - Roberts, P.
AU - Jones, D. L.
AU - Huang, Danfeng
AU - Iwasaki, K.
PY - 2009/9
Y1 - 2009/9
N2 - Direct uptake of organic nitrogen (ON) compounds, rather than inorganic N, by plant roots has been hypothesized to constitute a significant pathway for plant nutrition. The aim of this study was to test whether tomatoes (Solanum lycopersicum cv. Huying932) can take up ON directly from the soil by using 15NH4Cl, K15NO3, 1, 2-13C215N-glycine labeling techniques. The 13C and 15N in the plants increased significantly indicating that a portion of the glycine-N was taken up in the form of intact amino acids by the tomatoes within 48 h after injection into the soil. Regression analysis of excess 13C against excess 15N showed that approximately 21% of the supplied glycine-N was taken up intact by the tomatoes. Atom% excesses of 15N and 13C in the roots were higher than in any shoots. Results also indicated rapid turnover of amino acids (e.g., glycine) by soil microorganisms, and the poor competitive ability of tomatoes in absorbing amino acids from the soil solution. This implies that tomatoes can take up ON in an intact form from the soil despite the rapid turnover of organic N usually found under such conditions. Given the influence of climatic change and N pollution, further studies investigating the functional ecological implications of ON in horticultural ecosystems are warranted. Crown
AB - Direct uptake of organic nitrogen (ON) compounds, rather than inorganic N, by plant roots has been hypothesized to constitute a significant pathway for plant nutrition. The aim of this study was to test whether tomatoes (Solanum lycopersicum cv. Huying932) can take up ON directly from the soil by using 15NH4Cl, K15NO3, 1, 2-13C215N-glycine labeling techniques. The 13C and 15N in the plants increased significantly indicating that a portion of the glycine-N was taken up in the form of intact amino acids by the tomatoes within 48 h after injection into the soil. Regression analysis of excess 13C against excess 15N showed that approximately 21% of the supplied glycine-N was taken up intact by the tomatoes. Atom% excesses of 15N and 13C in the roots were higher than in any shoots. Results also indicated rapid turnover of amino acids (e.g., glycine) by soil microorganisms, and the poor competitive ability of tomatoes in absorbing amino acids from the soil solution. This implies that tomatoes can take up ON in an intact form from the soil despite the rapid turnover of organic N usually found under such conditions. Given the influence of climatic change and N pollution, further studies investigating the functional ecological implications of ON in horticultural ecosystems are warranted. Crown
KW - 1, 2-CN-glycine
KW - N acquisition
KW - Amino acid uptake
KW - Plant-microbial competition
KW - Tomato (Solanum lycopersicum)
UR - http://www.scopus.com/inward/record.url?scp=67349175278&partnerID=8YFLogxK
U2 - 10.1016/j.envexpbot.2009.05.004
DO - 10.1016/j.envexpbot.2009.05.004
M3 - Article
AN - SCOPUS:67349175278
VL - 66
SP - 357
EP - 361
JO - Environmental and Experimental Botany
JF - Environmental and Experimental Botany
SN - 0098-8472
IS - 3
ER -