Figure 8.

syp121 complementation with SYP121^R20AR21A affects Arabidopsis growth but only to a lesser extent affects the K⁺ and osmotic contents. A, Root (top) and hypocotyl (bottom) growth of syp121 Arabidopsis lines stably expressing SYP121, SYP121n1, SYP121n2, SYP121n3, and SYP121^R20AR21A under the control of the UBQ10 promoter (Grefen et al., 2010b); the wild type and syp121 and syp122 lines were used as controls. For root measurements, plants were grown for 10 d in liquid culture with defined minimal salts medium including 1 mm K⁺ at 22°C and 200 μmol m⁻² s⁻¹ photosynthetically active radiation (Honsbein et al., 2009). For hypocotyl growth measurements, seed germination was activated by placing the plates under a red filter for 3 h and then transferred to darkness for 6 d. Bars = 1 cm. B, Root (top) and hypocotyl (bottom) lengths of Arabidopsis lines depicted in A determined as means ± se from three independent experiments with more than 10 seedlings for each line. All lengths are normalized to that of the wild type grown in parallel. Significant differences (P < 0.05) are indicated by different letters. C, Mean ± se of total K⁺ contents of seedlings collected from the same plants used for root growth measurements. Significant differences (P < 0.05) are indicated by different letters. D, Mean ± se of total osmotic contents as in C. Significant differences (P < 0.05) are indicated by different letters.