HKT2;2/1, a Kâº-permeable transporter identified in a salt-tolerant rice cultivar through surveys of natural genetic polymorphism.
Plant J
; 71(5): 750-62, 2012 Sep.
Article
en En
| MEDLINE
| ID: mdl-22530609
ABSTRACT
We have investigated OsHKT2;1 natural variation in a collection of 49 cultivars with different levels of salt tolerance and geographical origins. The effect of identified polymorphism on OsHKT2;1 activity was analysed through heterologous expression of variants in Xenopus oocytes. OsHKT2;1 appeared to be a highly conserved protein with only five possible amino acid substitutions that have no substantial effect on functional properties. Our study, however, also identified a new HKT isoform, No-OsHKT2;2/1 in Nona Bokra, a highly salt-tolerant cultivar. No-OsHKT2;2/1 probably originated from a deletion in chromosome 6, producing a chimeric gene. Its 5' region corresponds to that of OsHKT2;2, whose full-length sequence is not present in Nipponbare but has been identified in Pokkali, a salt-tolerant rice cultivar. Its 3' region corresponds to that of OsHKT2;1. No-OsHKT2;2/1 is essentially expressed in roots and displays a significant level of expression at high Na⺠concentrations, in contrast to OsHKT2;1. Expressed in Xenopus oocytes or in Saccharomyces cerevisiae, No-OsHKT2;2/1 exhibited a strong permeability to Na⺠and Kâº, even at high external Na⺠concentrations, like OsHKT2;2, and in contrast to OsHKT2;1. Our results suggest that No-OsHKT2;2/1 can contribute to Nona Bokra salt tolerance by enabling root K⺠uptake under saline conditions.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Proteínas de Plantas
/
Oryza
/
Proteínas de Transporte de Catión
/
Tolerancia a la Sal
Límite:
Animals
Idioma:
En
Revista:
Plant J
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Año:
2012
Tipo del documento:
Article
País de afiliación:
Francia