Supply of sulphur to S-deficient young barley seedlings restores their capability to cope with iron shortage

Abstract

The effect of the S nutritional status on a plant's capability to cope with Fe shortage was studied in solution cultivation experiments in barley (Hordeum vulgare L. cv. Europa). Barley is a Strategy II plant and responds to Fe deficiency by secretion of chelating compounds, phytosiderophores (PS). All PS are derived from nicotianamine whose precursor is methionine. This suggests that a long-term supply of an inadequate amount of S could reduce a plant's capability to respond to Fe deficiency by limiting the rate of PS biosynthesis. The responses of barley (Hordeum vulgare L. cv. Europa) plants grown for 12 d on Fe-free nutrient solutions (NS) containing 0 or 1.2 mM SO42−, was examined after 24 h or 48 h from transfer to NS containing 1.2 mM SO42−. After the supply of S was restored to S-deprived plants, an increase in PS release in root exudates was evident after 24 h of growth in S-sufficient NS and the increment reached values up to 4-fold higher than the control 48 h after S resupply. When S was supplied to S-deficient plants, leaf ATPS (EC 2.7.7.4) and OASTL (EC 4.2.99.8) activities exhibited a progressive recovery. Furthermore, root HvST1 transcript abundance remained high for 48 h following S resupply and a significant increase in the level of root HvYS1 transcripts was also found after only 24 h of S resupply. Data support the idea that the extent to which the plant is able to cope with Fe starvation is strongly associated with its S nutritional status. In particular, our results are indicative that barley plants fully recover their capability to cope with Fe shortage after the supply of S is restored to S-deficient plants.

Chlorophyll a fluorescence in two varieties of sugar cane subjected to aluminum and water stress

“…It is known that S has significant role in the mechanisms of absorption of ions nutrients (Astolfi et al, 2010) and besides being crucial in the synthesis of amino acids, proteins (including major and D2-D1 Protein) and chlorophyll (Godde and Dannehl, 1994) its soil displacement and role in reducing the toxic effects of aluminum has been found to explain the productivity increase in sugar cane (Silva et al, 2007), which requires further investigation about the effect of this element on fluorescence chlorophyll parameters, especially in Saccharum spp physiological studies. Among the fluorescence parameters of chlorophyll a approached in this study, the results obtained by means of the OJIP test were the most efficient for the distinction of varieties (Figures 3 and 4).…”

Effect of Elemental Sulfur as Fertilizer Ingredient on the Mobilization of Iron from the Iron Pools of a Calcareous Soil Cultivated with Durum Wheat and the Crop’s Iron and Sulfur Nutrition

“…On the other hand, the interactions between iron nutrition and sulfur nutrition have received increasing attention. The finding that methionine is the sole percursor of mugineic acid [30] and the demonstration that the methionine cycle (or Yang cycle) in roots is one of the methionine sources [31] led Astolfi et al [21,32,33] to further investigate the interactions between Fe nutrition and S nutrition, concluding that "the interaction can occur determining rapid adjustments of sulfate uptake and assimilation which conceivably lead to a re-distribution of reduced S pool. Fe availability might represent a signal able to modulate production and utilization of thiols at root level, where phytosiderophores are effectively synthesized" [32].…”

Regulation of Phytosiderophore Release and Antioxidant Defense in Roots Driven by Shoot-Based Auxin Signaling Confers Tolerance to Excess Iron in Wheat

“…Also, expression of genes involved in the synthesis of MA ( HvNAAT-A and HvDMAS1 ) and in the Fe uptake ( HvTOM1, HvYS1, HvIRT1, HvNramp2, HvNramp5 , and HvNarmp7 ) in barley upon Fe deficiency (Astolfi et al, 2010, 2014). However, DMA is also detected in Fe-sufficient shoot in rice possibly involved in Fe translocation as Fe-DMA complex (Mori et al, 1991).…”