Is white clover able to switch to atmospheric sulphur sources when sulphate availability decreases?

• Published in: Journal of experimental botany Vol. 64; no. 8; pp. 2511 - 2521
• Main Authors: Varin, Sébastien, Lemauviel-Lavenant, Servane, Cliquet, Jean-Bernard
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press [etc.] 01.05.2013; Oxford University Press; Oxford University Press (OUP)
• Subjects: Atmosphere - analysis; atmospheric deposition; Atmospherics; Biological and medical sciences; clones; Clover; Environmental Sciences; Fundamental and applied biological sciences. Psychology; hydroponics; Leaves; Life Sciences; Nutrient solutions; nutrients; Nutrition; plant age; Plant growth; Plant Leaves - chemistry; Plant Leaves - physiology; Plant physiology and development; Plant roots; Plant Roots - chemistry; Plant Roots - physiology; Plant Shoots - chemistry; Plant Shoots - physiology; Plants; proteins; RESEARCH PAPER; Root Nodules, Plant - chemistry; Root Nodules, Plant - physiology; roots; Soil - chemistry; Stolons; Sulfates - analysis; Sulfates - metabolism; Sulfur; Sulfur - analysis; Sulfur - metabolism; sulfur dioxide; Trifolium - chemistry; Trifolium - metabolism; Trifolium - physiology; Trifolium repens; sulphate uptake; sulphur deposition; Plant leaf; Sulfates; Absorption; S; Foliar uptake; Leguminosae; sulphur deficiency; Dicotyledones; Atmosphere; Angiospermae; Botany; Plasticity; Spermatophyta; Fodder crop; Sulfur; Deposition; Trifolium repens; plasticity; 34S; S DEFICIENCY; ARABIDOPSIS-THALIANA; PHENOTYPIC PLASTICITY; PISUM-SATIVUM L; NITROGEN-FIXATION; CURLY KALE; TRIFOLIUM-REPENS L; CHINESE-CABBAGE; N-2 FIXATION; BRASSICA-OLERACEA; S-34
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/ert109

Sulphur (S) is one of the very few nutrients that plants can absorb either through roots as sulphate or via leaves in a gas form such as SO2 or H2S. This study was realized in a non-S-enriched atmosphere and its purpose was to test whether clover plants can increase their ability to use atmospheric S when sulphate availability decreases. A novel methodology measuring the dilution of 34S provided from a nutrient solution by atmospheric 32S was developed to measure S acquisition by Trifolium repens L. Clones of white clover were grown for 140 d in a hydroponic system with three levels of sulphate concentrations. S concentration in plants decreased with S deficiency and plant age. In the experimental conditions used here, S derived from atmospheric deposition (Sdad) constituted from 36% to 100% of the total S. The allocation of S coming from atmospheric and pedospheric sources depends on organs and compounds. Nodules appeared as major sinks for sulphate. A greater proportion of atmospheric S was observed in buffer-soluble proteins than in the insoluble S fraction. Decreasing the S concentration in the nutrient solution resulted in an increase in the Sdad:leaf area ratio and in an increase in the leaf:stolon and root:shoot mass ratios, suggesting that a plasticity in the partitioning of resources to organs may allow a higher gain of S by both roots and leaves. This study shows that clover can increase its ability to use atmospheric S even at low concentration when pedospheric S availability decreases.