Selenium species in selenium-enriched and drought-exposed potatoes.
The aim of this work was to study selenium (Se) speciation in the potato ( Solanum tuberosum L.) cultivar Desiree, enriched in Se by foliar spraying with a water solution containing 10 mg of Se/L in the form of sodium selenate. Four combinations of treatments were used: well-watered plants with and without Se foliar spraying and drought-exposed plants with and without Se foliar spraying. Water-soluble Se compounds were extracted from potato tubers by water or enzymatic hydrolysis with the enzyme protease XIV, amylase, or a combination of protease XIV and amylase. Extraction was performed using incubation at a constant temperature and stirring (37 degrees C at 200 rpm) or by ultrasound-assisted extraction (300 W), using different extraction times. Separation of soluble Se species (SeCys2, SeMet, SeMeSeCys, selenite, and selenate) was achieved by ion-exchange chromatography, and detection was performed by inductively coupled plasma-mass spectrometry (ICP-MS). Results showed that the concentration of selenate extracted was independent of the enzymatic extraction technique (approximately 98 ng/g for drought-exposed and 308 ng/g for well-watered potato tubers), whereas the extraction yield of SeMet changed with the protocol used (10-36%). Selenate and SeMet were the main soluble Se species (representing 51-68% of total Se) in potato tubers, regardless of the growth conditions.
Cuderman
Petra
P
Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1111 Ljubljana, Slovenia.
Kreft
Ivan
I
Germ
Mateja
M
Kovacevic
Miroslav
M
Stibilj
Vekoslava
V
D002851:Chromatography, High Pressure Liquid; D055864:Droughts; D064586:Selenic Acid; D012643:Selenium / Q000008:administration & dosage*; D018036:Selenium Compounds / Q000032:analysis* / Q000302:isolation & purification; D017279:Selenocysteine / Q000032:analysis; D012645:Selenomethionine / Q000032:analysis; D018038:Sodium Selenite / Q000032:analysis; D011198:Solanum tuberosum / Q000737:chemistry*; D012996:Solutions
D018036:Selenium Compounds; D012996:Solutions; D017279:Selenocysteine; D012645:Selenomethionine; D012643:Selenium; D018038:Sodium Selenite; D064586:Selenic Acid