ZmHAK5 and ZmHAK1 function in K + uptake and distribution in maize under low K + conditions.

Autor: Qin YJ; State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, China Agricultural University, Beijing 100193, China.; Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100193, China., Wu WH; State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, China Agricultural University, Beijing 100193, China.; Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100193, China., Wang Y; State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, China Agricultural University, Beijing 100193, China.; Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100193, China.
Jazyk: angličtina
Zdroj: Journal of integrative plant biology [J Integr Plant Biol] 2019 Jun; Vol. 61 (6), pp. 691-705. Date of Electronic Publication: 2019 Feb 01.
DOI: 10.1111/jipb.12756
Abstrakt: Potassium (K + ) is an essential macronutrient for plant growth and development. Transporters from the KT/HAK/KUP family play crucial roles in K + homeostasis and cell growth in various plant species. However, their physiological roles in maize are still unknown. In this study, we cloned ZmHAK5 and ZmHAK1 and investigated their functions in maize (Zea mays L.). In situ hybridization showed that ZmHAK5 was mainly expressed in roots, especially in the epidermis, cortex, and vascular bundle. ZmHAK5 was characterized as a high-affinity K + transporter. Loss of function of ZmHAK5 led to defective K + uptake in maize, under low K + conditions, whereas ZmHAK5-overexpressing plants showed increased K + uptake activity and improved growth. ZmHAK1 was upregulated under low K + stress, as revealed by RT-qPCR. ZmHAK1 mediated K + uptake when heterologously expressed in yeast, but its transport activity was weaker than that of ZmHAK5. Overexpression of ZmHAK1 in maize significantly affected K + distribution in shoots, leading to chlorosis in older leaves. These findings indicate that ZmHAK5 and ZmHAK1 play distinct roles in K + homeostasis in maize, functioning in K + uptake and K + distribution, respectively. Genetic manipulation of ZmHAK5 may represent a feasible way to improve K + utilization efficiency in maize.
(© 2018 Institute of Botany, Chinese Academy of Sciences.)
Databáze: MEDLINE
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