Open AccessRoot-zone-specific sensitivity of K+-and Ca2+-permeable channels to H2O2 determines ion homeostasis in salinized diploid and hexaploid Ipomoea trifida
Author(s) -
Yang Liu,
Yan Yu,
Junling Sun,
Qinghe Cao,
Zhonghou Tang,
Meiyan Liu,
Tao Xu,
Daifu Ma,
Zongyun Li,
Jian Sun
Publication year - 2019
Publication title -
journal of experimental botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.616
H-Index - 242
eISSN - 1460-2431
pISSN - 0022-0957
DOI - 10.1093/jxb/ery461
Subject(s) - homeostasis , ploidy , botany , biology , elongation , biophysics , chemistry , microbiology and biotechnology , biochemistry , gene , materials science , ultimate tensile strength , metallurgy
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.