Common reed absorbs K⁺ more selectively than rice against high Na⁺/K⁺ ratio in nutrient solution

Abstract

The introduction of an active Na + excretion system from salt-tolerant plants in salt-sensitive crop plants might necessitate enhancement of the robustness of K + homeostasis and lead to improved plant growth under salt stress. To address this issue, we compared the acquisition and retention of K + under excess Na + concentrations in the common reed, which possesses excellent Na + excretion ability, and low-Na + excreting rice. Under excess Na + concentrations, common reed maintained constant K + content in all plant parts, whereas K + content in rice decreased with increasing Na + concentration. Preferential uptake of K + against high Na + /K + ratio in nutrient solution was approximately 10 times higher in common reed than in rice. The impact of excess Na + on net K + absorption rate of common reed was small. On the other hand, the net K + absorption rate of rice was decreased by excess Na + concentration. However, after the Na + concentration in the nutrient solution was decreased from 50 to 1 mM, K + absorption in rice recovered immediately. Thus, selectivity of K + transporters or channels for K + over Na + in roots could be involved in the differences in K + accumulation in rice and common reed.

Nutritional Efficiency and Morphophysiological Aspects With Growth in the ‘Okinawa Roxo’ Peach Rootstock

“…With respect to the quality of the root system in the commercial substrate (T3), the roots were more fragile, breaking easily when removed from the substrate for chemical analysis of the macro-and micronutrients. This can be attributed to insufficient levels of the nutrients P, K and Ca in the plants from T3 affecting the quality and development of new roots (Higuchi & Hara, 2017). The deficiency of such nutrients as Ca may present serious restrictions to root development, since this nutrient has limited internal redistribution due to its low mobility (Vliet & Giller, 2017).…”