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

Abstract

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 34SO42− and 15NO3− 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.

Evidence for Proteomic and Metabolic Adaptations Associated with Alterations of Seed Yield and Quality in Sulfur-limited Brassica napus L

“…Previous research emphasized the crucial role of leaves as the major source organ for S in response to S restriction (4). Despite enhancement of the S remobilization processes, the LS70, LS53, and LS32 treatments led to a reduction of the S content Significant analysis of variance was followed by a Mann-Whitney test (p Ͻ 0.05) carried out on the normalized spot volumes (n ϭ 6 for control; n ϭ 4 for LS70, LS53, and LS32).…”

“…The reduction of S atmospheric deposits observed over recent decades has forced farmers to add S fertilizer in order to maintain seed yield and quality. A previous study highlighted the necessity of satisfying plant S requirements until the start of pod filling to ensure yield as well as high lipid and protein contents (4). These observations emphasize the importance of a detailed understanding of the impact of S limitation on seed oil and protein quality and of the processes involved.…”

Response of Rice Yield and Soil to Sulfur Application under Water and Salinity Stresses

“…Sulfur deficiency has become widespread in many countries, many soils are declining their sulfur fertility due to an intensive agriculture using fertilizers highly enriched in NPK (Zhao et al, 1999). S-deficiency results in general inhibition of photosynthesis and protein synthesis (Dubousset et al, 2010). S-deficiency reduces chlorophyll and rubisco content , and provokes chlorosis of young leaves (Muneer et al, 2014).…”

Variation in Sulfur and Selenium Accumulation Is Controlled by Naturally Occurring Isoforms of the Key Sulfur Assimilation Enzyme ADENOSINE 5′-PHOSPHOSULFATE REDUCTASE2 across the Arabidopsis Species Range

“…However, animals can only utilize sulfur that has been incorporated into biomolecules primarily originating from plants. Sufficient sulfur fertilization is also important to maximize yields of various crops, including rapeseed (Brassica napus) and wheat (Triticum aestivum; Bloem et al, 2004;Dubousset et al, 2010;Steinfurth et al, 2012). Interestingly, sulfur fertilization can also be important for food quality, with well-fertilized wheat crops producing flour with improved bread-making qualities (Shahsavani and Gholami, 2008).…”

“…Regulations controlling the release of sulfur dioxide from power stations introduced in the 1970s have caused significant declines in sulfate deposition due to this acid rain (Menz and Seip, 2004). These reductions in sulfate deposition are significant enough to have increased the need for sulfur fertilization of agricultural crops such as rapeseed and wheat (Dubousset et al, 2010;Steinfurth et al, 2012). The essentiality of sulfur for plants and the relatively recent major fluctuations in soil sulfate deposition make the study of natural variation in sulfur homeostasis by plants attractive.…”