Supply of sulphur to S-deficient young barley seedlings restores their capability to cope with iron shortage.
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 SO(4)(2-), was examined after 24 h or 48 h from transfer to NS containing 1.2 mM SO(4)(2-). 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.
Astolfi
Stefania
S
Dipartimento di Agrobiologia e Agrochimica, Università della Tuscia, Via S.C. de Lellis snc, I-01100 Viterbo, Italy. sastolfi@unitus.it
Zuchi
Sabrina
S
Hubberten
Hans-Michael
HM
Pinton
Roberto
R
Hoefgen
Rainer
R
D025181:ATP Synthetase Complexes / Q000378:metabolism; D000222:Adaptation, Physiological / Q000187:drug effects*; D018533:Biomass; D002734:Chlorophyll / Q000378:metabolism; D003547:Cysteine Synthase / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D001467:Hordeum / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D000090463:Iron Deficiencies; D008715:Methionine / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000378:metabolism*; D017262:Siderophores / Q000378:metabolism; D013455:Sulfur / Q000172:deficiency* / Q000494:pharmacology*
D010940:Plant Proteins; D017262:Siderophores; D002734:Chlorophyll; D013455:Sulfur; D008715:Methionine; D003547:Cysteine Synthase; D025181:ATP Synthetase Complexes