Journal
PLANT JOURNAL
Volume 91, Issue 4, Pages 657-670Publisher
WILEY
DOI: 10.1111/tpj.13595
Keywords
salt tolerance; Na+ exclusion; HKT; xylem; phloem; Oryza sativa
Categories
Funding
- Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan [25119709]
- MEXT as part of the Joint Research Program implemented at the Institute of Plant Science and Resources, Okayama University in Japan [2615, 2716]
- Public Foundation of Chubu Science and Technology Center
- Japan Science and Technology Agency (JST) [PRESTO] [15665950]
- Ministero dell'Istruzione, dell'Universita e della Ricerca through the FIRB program [RBFR10S1LJ_001]
- Linea 2 Project from the University of Milan
- Department of Industry, Innovation and Science
- National Institutes of Environmental Health Sciences grant [P42 ES010337]
- Grants-in-Aid for Scientific Research [16H06296, 15H04493] Funding Source: KAKEN
Ask authors/readers for more resources
Salt tolerance quantitative trait loci analysis of rice has revealed that the SKC1 locus, which is involved in a higher K+/Na+ ratio in shoots, corresponds to the OsHKT1;5 gene encoding a Na+-selective transporter. However, physiological roles of OsHKT1;5 in rice exposed to salt stress remain elusive, and no OsHKT1;5 gene disruption mutants have been characterized to date. In this study, we dissected two independent TDNA insertional OsHKT1;5 mutants. Measurements of ion contents in tissues and 22 Na+ tracer imaging experiments showed that loss-of-function of OsHKT1;5 in salt-stressed rice roots triggers massive Na+ accumulation in shoots. Salt stress-induced increases in the OsHKT1;5 transcript were observed in roots and basal stems, including basal nodes. Immuno-staining using an anti-OsHKT1;5 peptide antibody indicated that OsHKT1;5 is localized in cells adjacent to the xylem in roots. Additionally, direct introduction of 22 Na+ tracer to leaf sheaths also demonstrated the involvement of OsHKT1;5 in xylem Na+ unloading in leaf sheaths. Furthermore, OsHKT1;5 was indicated to be present in the plasma membrane and found to localize also in the phloem of diffuse vascular bundles in basal nodes. Together with the characteristic 22 Na+ allocation in the blade of the developing immature leaf in the mutants, these results suggest a novel function of OsHKT1;5 in mediating Na+ exclusion in the phloem to prevent Na+ transfer to young leaf blades. Our findings further demonstrate that the function of OsHKT1;5 is crucial over growth stages of rice, including the protection of the next generation seeds as well as of vital leaf blades under salt stress.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available