The impact of sulfate restriction on seed yield and quality of winter oilseed rape depends on the ability to remobilize sulfate from vegetative tissues to reproductive organs

Abstract

Our current knowledge about sulfur (S) management by winter oilseed rape to satisfy the S demand of developing seeds is still scarce, particularly in relation to S restriction. Our goals were to determine the physiological processes related to S use efficiency that led to maintain the seed yield and quality when S limitation occurred at the bolting or early flowering stages. To address these questions, a pulse-chase 34SO2−4 labeling method was carried out in order to study the S fluxes from uptake and remobilization at the whole plant level. In response of S limitation at the bolting or early flowering stages, the leaves are the most important source organ for S remobilization during reproductive stages. By combining 34S-tracer with biochemical fractionation in order to separate sulfate from other S-compounds, it appeared that sulfate was the main form of S remobilized in leaves at reproductive stages and that tonoplastic SULTR4-type transporters were specifically involved in the sulfate remobilisation in case of low S availability. In response to S limitation at the bolting stage, the seed yield and quality were dramatically reduced compared to control plants. These data suggest that the increase of both S remobilization from source leaves and the root proliferation in order to maximize sulfate uptake capacities, were not sufficient to maintain the seed yield and quality. When S limitation occurred at the early flowering stage, oilseed rape can optimize the mobilization of sulfate reserves from vegetative organs (leaves and stem) to satisfy the demand of seeds and maintain the seed yield and quality. Our study also revealed that the stem may act as a transient storage organ for remobilized S coming from source leaves before its utilization by seeds. The physiological traits (S remobilization, root proliferation, transient S storage in stem) observed under S limitation could be used in breeding programs to select oilseed rape genotypes with high S use efficiency.

Effect of Sulphur Application on Photosynthesis and Biomass Accumulation of Sesame Varieties under Rainfed Conditions

“…Sulphur application increased the availability of other major nutrients N, P and K [5] and enhanced sesame growth under drought conditions [6]. Its deficiency negatively affects the crop growth phases, crop maturity [8,9] and oil quality of oilseed crops [10,11]. Moreover, application of low S or S free fertilizers has decreased the S inputs to agriculture fields during the last 20 years [12].…”

“…The higher seed yield production has increased the rate of sulphur removal from soil [6,13]. Oilseed crops need more S than cereal crops because it promotes pod initiation, whereas a deficiency of S aborts pods [10]. Overall, an optimum amount of S application considerably enhances the sesame growth [2] and seed quality by increasing the oleic acid content in oilseeds [11].…”

Effect of molybdenum levels on photosynthetic characteristics, yield and seed quality of two oilseed rape (Brassica napus L.) cultivars

“…Oilseed rape (Brassica napus L.), one of the three major oil crops in the world, provides edible oil and raw materials for bio-energy production (Karp and Richter 2011;Girondé et al 2014). As one of the most important commercial and agricultural crops, oilseed rape is sensitive to Mo deficiency in soil, which affects its growth, production and seed quality.…”

The Effect of Fertilization with Sulphur, Boron, and Amino Acids on the Content of Glucosinolate in Winter Rape Seeds

“…Many authors [3][4][5][6] believe that the demand for rapeseed for sulphur (S) and boron (B) is large and amounts to 20 to 30 kg S·ha −1 [7], while for boron it amounts to 145 to 290 g·ha −1 [8]. Zhao et al [9] reported that sulphur and boron are necessary for the synthesis of glucosinolates and sulphur amino acids.…”

“…Sulphur is absorbed by the roots in the form of sulphate ion SO 4 2-and transported via xyl to the leaves. The sulphate ion is reduced in the leaves mainly to cysteine and/or transformed into methionine or incorporated into proteins [7,10]. According to Wielebski [11], the most important functions of sulphur in a plant result from the presence of this component in sulphur amino acids (cystine, cysteine, and methionine), which participate in the formation of proteins, and are also precursors of other important compounds, such as glucosinolates, glutathione, thiamine (vitamin B1), biotin (vitamin H), coenzyme A, lipoic acid, thioredoxins, and sulpholipids.…”