OsPT2, a phosphate transporter, is involved in the active uptake of selenite in rice

• Published in: The New phytologist Vol. 201; no. 4; pp. 1183 - 1191
• Main Authors: Zhang, Lianhe, Hu, Bin, Li, Wei, Che, Ronghui, Deng, Kun, Li, Hua, Yu, Feiyan, Ling, Hongqing, Li, Youjun, Chu, Chengcai
• Format: Journal Article
• Language: English
• Published: England New Phytologist Trust 01-03-2014; Wiley Subscription Services, Inc; BlackWell Publishing Ltd
• Subjects: 2,4-Dinitrophenol - pharmacology; Biological Transport, Active - drug effects; Breeding; Carbonyl Cyanide m-Chlorophenyl Hydrazone - analogs & derivatives; Carbonyl Cyanide m-Chlorophenyl Hydrazone - pharmacology; Gene Expression Regulation, Plant - drug effects; Genes, Plant - genetics; Grains; Hydrogen - metabolism; molecular mechanism; Mutants; Mutation - genetics; Oryza - drug effects; Oryza - genetics; Oryza - metabolism; Phosphate transport proteins; Phosphate Transport Proteins - genetics; Phosphate Transport Proteins - metabolism; Phosphate transporter; Phosphates; Phosphates - metabolism; Plant breeding; Plant Epidermis - cytology; Plant physiology; Plant Proteins - genetics; Plant Proteins - metabolism; Plant roots; Plant Roots - drug effects; Plant Roots - metabolism; Plants; Plants, Genetically Modified; Rice; rice (Oryza sativa); RNA, Messenger - genetics; RNA, Messenger - metabolism; Seedlings; Selenious Acid - metabolism; Selenite; selenite uptake; Selenites; Selenium; selenium (Se); Selenium - metabolism; Soil; Starvation; Sulfur - metabolism; Symporters - metabolism; Time Factors; Transgenic plants; Uptake; selenite uptake; molecular mechanism; rice (Oryza sativa); selenium (Se); phosphate transporter
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.12596

Selenite is a predominant form of selenium (Se) available to plants, especially in anaerobic soils, but the molecular mechanism of selenite uptake by plants is not well understood.
ltn1, a rice mutant previously shown to have increased phosphate (Pi) uptake, was found to exhibit higher selenite uptake than the wild-type in both concentration- and time-dependent selenite uptake assays. Respiratory inhibitors significantly inhibited selenite uptake in the wildtype and the ltn1 mutant, indicating that selenite uptake was coupled with H+ and energydependent. Selenite uptake was greatly enhanced under Pi-starvation conditions, suggesting that Pi transporters are involved in selenite uptake.
OsPT2, the most abundantly expressed Pi transporter in the roots, is also significantly upregulated in ltn1 and dramatically induced by Pi starvation. OsPT2-overexpressing and knockdown plants displayed significantly increased and decreased rates of selenite uptake, respectively, suggesting that OsPT2 plays a crucial role in selenite uptake. Se content in rice grains also increased significantly in OsPT2-overexpressing plants.
These data strongly demonstrate that selenite and Pi share similar uptake mechanisms and that OsPT2 is involved in selenite uptake, which provides a potential strategy for breeding Seenriched rice varieties.