Is the remobilization of S and N reserves for seed filling of winter oilseed rape modulated by sulphate restrictions occurring at different growth stages?

• Published in: Journal of experimental botany Vol. 61; no. 15; pp. 4313 - 4324
• Main Authors: Dubousset, L, Etienne, P, Avice, J.C
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.10.2010
• Subjects: 34S and 15N labelling; Biological and medical sciences; Biological Transport; Biomass; bolting; Brassica napus var. napus; Brassica rapa; Brassica rapa - growth & development; Brassica rapa - metabolism; buds; Crop harvesting; Fatty Acids, Monounsaturated; Filling period; Fundamental and applied biological sciences. Psychology; growth & development; Leaves; metabolism; Minerals; Nitrogen; Nitrogen - metabolism; Oilseed rape; Oilseeds; Plant Leaves; Plant Leaves - metabolism; Plant Oils; Plant Oils - metabolism; Plant roots; Plants; pods; rapeseed; Rapeseed Oil; RESEARCH PAPER; Research Papers; roots; S remobilization efficiency; S utilization efficiency; Seasons; seed quality; Seeds; Seeds - growth & development; Seeds - metabolism; source-sink relationships; stems; sulfates; Sulfates - metabolism; Sulfur; Sulfur Isotopes; sulphate restriction; surveys; yield components; Oilseed rape; Brassica napus var. oleifera; Isotope labelling; S utilization efficiency; Grain filling; S and; Sulfates; sulphate restriction; Cruciferae; Remobilization; Dicotyledones; Modulation; Winter crops; N labelling; Angiospermae; Botany; Nitrogen-15; Spermatophyta; Developmental stage; S remobilization efficiency; Oil plant (vegetal)
• ISSN: 0022-0957; 1460-2431; 1460-2431
• DOI: 10.1093/jxb/erq233

How the remobilization of S and N reserves can meet the needs of seeds of oilseed rape subject to limitation of S fertilization remains largely unclear. Thus, this survey aims to determine the incidence of sulphate restriction [low S (LS)] applied at bolting [growth stage (GS) 32], visible bud (GS 53), and start of pod filling (GS 70) on source-sink relationships for S and N, and on the dynamics of endogenous/exogenous S and N contributing to seed yield and quality. Sulphate restrictions applied at GS 32, GS 53, and GS 70 were annotated LS₃₂, LS₅₃, and LS₇₀. Long-term ³⁴SO[Formula: see text] and ¹⁵NO[Formula: see text] labelling was used to explore S and N partitioning at the whole-plant level. In LS₅₃, the sulphur remobilization efficiency (SRE) to seeds increased, but not enough to maintain seed quality. In LS₃₂, an early S remobilization from leaves provided S for root, stem, and pod growth, but the subsequent demand for seed development was not met adequately and the N utilization efficiency (NUtE) was reduced when compared with high S (HS). The highest SRE (65±1.2% of the remobilized S) associated with an efficient foliar S mobilization (with minimal residual S concentrations of 0.1-0.2% dry matter) was observed under LS₇₀ treatment, which did not affect yield components.