[Effect of sulfate supply level on characteristics of N and S metabolism and on root vigor of corn].
The effects of different sulfate supply level on N and S metabolism and on root vigor of corn were quantitatively studied with Hoagland solution under greenhouse conditions. The results showed that in S-deficient solution, root vigor and leaf nitrate reductase (NR) activity significantly rdduced, top root ratio (T/R) increased, and S and N accumulation in tops and roots decreased. The partition of S decreased in roots and incompletely expanded leaves, but increased in senescent leaves and sheaths-stems; while the partition of N increased in roots, but decreased in incompletely and fully expanded leaves. The content of protein, protein N, protein S, and sulfate S significantly reduced, percentage of non-protein N increased, inorganic S/total S ratio decreased, and total N/total S ratio increased. The protein N/protein S ratio in tops had no observable changes, but increased significantly in roots, showing that root was a sensitive organ to S-deficiency. There was a close relationship between protein content and NR activity in S-deficiency. Deficient or excessive S supply limited N and S metabolism of corn plant. N/S or inorganic S/total S ratio in roots was a sensitive index to indicate the deficiency of S supply, which was 10.7 or 0.302 under normal condition, respectively.
Wang
Kongjun
K
Laboratory of Quantitative Vegetation Ecology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China. kjwang@sdau.edu.cn
Hu
Changhao
C
Dong
Shuting
S
Liu
Kaichang
K
Liu
Cunhui
C
D009584:Nitrogen / Q000378:metabolism*; D018517:Plant Roots / Q000502:physiology*; D013431:Sulfates / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism*; D003313:Zea mays / Q000378:metabolism*
D013431:Sulfates; D013455:Sulfur; D009584:Nitrogen