Figure 9.

Functional Characterization of NRT1.5 Putative Orthologs.

(A) K⁺ efflux activities of the X. laevis oocytes expressing NRT1.5, NRT1.8, and NPF7.1.

(B) K⁺ efflux activities of the X. laevis oocytes expressing NRT1.5 putative orthologs from rice and maize. All the data in (A) and (B) are shown as mean ± se from five samples (n = 5), and each sample contained five oocytes. The Student’s t test (**P < 0.01) was used to analyze statistical significance.

(C) and (D) Real-time PCR analyses of ZmNPF7.10 (C) and OsNPF7.9 (D) in maize and rice responses to low K⁺ stress. Maize (B73-329) seedlings were cultured in solution containing different K⁺ concentrations (+K, 1.85 mM K⁺ and –K, 0 K⁺) for 1 and 3 d. UBQ was used as the internal control. Data are mean ± se (n = 3). Data in (D) were derived from those reported in a previous study (Ma et al., 2012).