Root-zone-specific sensitivity of K+-and Ca2+-permeable channels to H2O2 determines ion homeostasis in salinized diploid and hexaploid Ipomoea trifida.
J Exp Bot
; 70(4): 1389-1405, 2019 02 20.
Article
in En
| MEDLINE
| ID: mdl-30689932
ABSTRACT
Polyploids generally possess superior K+/Na+ homeostasis under saline conditions compared with their diploid progenitors. In this study, we identified the physiological mechanisms involved in the ploidy-related mediation of K+/Na+ homeostasis in the roots of diploid (2x) and hexaploid (6x; autohexaploid) Ipomoea trifida, which is the closest relative of cultivated sweet potato. Results showed that 6x I. trifida retained more K+ and accumulated less Na+ in the root and leaf tissues under salt stress than 2x I. trifida. Compared with its 2x ancestor, 6x I. trifida efficiently prevents K+ efflux from the meristem root zone under salt stress through its plasma membrane (PM) K+-permeable channels, which have low sensitivity to H2O2. Moreover, 6x I. trifida efficiently excludes Na+ from the elongation and mature root zones under salt stress because of the high sensitivity of PM Ca2+-permeable channels to H2O2. Our results suggest the root-zone-specific sensitivity to H2O2 of PM K+- and Ca2+-permeable channels in the co-ordinated control of K+/Na+ homeostasis in salinized 2x and 6x I. trifida. This work provides new insights into the improved maintenance of K+/Na+ homeostasis of polyploids under salt stress.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Plant Proteins
/
Polyploidy
/
Plant Roots
/
Ipomoea
/
Diploidy
/
Hydrogen Peroxide
Type of study:
Diagnostic_studies
Language:
En
Journal:
J Exp Bot
Journal subject:
BOTANICA
Year:
2019
Document type:
Article
Affiliation country:
China