Identification and Characterization of Rice OsHKT1;3 Variants

Shahin Imran; Yoshiyuki Tsuchiya; Sen Thi Huong Tran; Maki Katsuhara

doi:10.3390/plants10102006

Identification and Characterization of Rice OsHKT1;3 Variants

Plants (Basel). 2021 Sep 24;10(10):2006. doi: 10.3390/plants10102006.

Authors

Shahin Imran^{1

2}, Yoshiyuki Tsuchiya¹, Sen Thi Huong Tran^{1

3}, Maki Katsuhara¹

Affiliations

¹ Institute of Plant Science and Resources, Okayama University, 2-20-1 Chuo, Kurashiki 710-0046, Japan.
² Department of Agronomy, Khulna Agricultural University, Khulna 9100, Bangladesh.
³ Faculty of Agronomy, University of Agriculture and Forestry, Hue University, Hue 530000, Vietnam.

Abstract

In rice, the high-affinity K⁺ transporter, OsHKT1;3, functions as a Na⁺-selective transporter. mRNA variants of OsHKT1;3 have been reported previously, but their functions remain unknown. In this study, five OsHKT1;3 variants (V1-V5) were identified from japonica rice (Nipponbare) in addition to OsHKT1;3_FL. Absolute quantification qPCR analyses revealed that the transcript level of OsHKT1;3_FL was significantly higher than other variants in both the roots and shoots. Expression levels of OsHKT1;3_FL, and some variants, increased after 24 h of salt stress. Two electrode voltage clamp experiments in a heterologous expression system using Xenopus laevis oocytes revealed that oocytes expressing OsHKT1;3_FL and all of its variants exhibited smaller Na⁺ currents. The presented data, together with previous data, provide insights to understanding how OsHKT family members are involved in the mechanisms of ion homeostasis and salt tolerance in rice.

Keywords: 3; Na+ transport; OsHKT1; TEVC; mRNA variants; rice.

Grants and funding

none/Ohara Foundation for Agricultural Science