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Overexpression of AtNHX1 increases leaf potassium content by improving enrichment capacity in tobacco (Nicotiana tabacum) roots.

Overexpression of AtNHX1 increases leaf potassium content by improving enrichment capacity in tobacco (Nicotiana tabacum) roots.

Authors :
Liu, Yong
Hou, Qian
Dong, Kunle
Chen, Yi
Wang, Zhihong
Xie, Shengdong
Wu, Shengjiang
Zhang, Xiaoquan
Yu, Shizhou
Yang, Zhixiao
Source :
Functional Plant Biology. 2024, Vol. 51 Issue 11, p1-14. 14p.
Publication Year :
2024

Abstract

The NHX1 gene encodes a Na+/H+ antiporter located in the tonoplast membrane, which plays critical role in regulating plant salt tolerance. It is also involved in the uptake and accumulation of K in plants; however, its precise mechanism is unknown. In this research, we elucidated the physiological basis underlying the increases in K content induced by NHX1. We evaluated main agronomic traits, leaf K content, K+ uptake kinetics, and root morphological and physiological characteristics from field-planted and hydroponic plants. We included a wild-type tobacco (Nicotiana tabacum) variety (K326) and three transgenic tobacco lines (NK7, NK9, NK10) that overexpress AtNHX1 from Arabidopsis thaliana. Results demonstrated that the agronomic performance of the AtNHX1 -overexpressing tobacco lines was similar to K326 in field and hydroponic settings. The three AtNHX1 -overexpressing tobacco lines had significantly higher leaf K contents than K326. Under hydroponic condition, enhanced K uptake capacity and a larger maximum K uptake rate were seen in AtNHX1 -overexpressing tobacco lines. AtNHX1 -overexpressing lines also exhibited significantly superior root morphological and physiological traits relative to K326, including root biomass, root volume, absorption area, root activity, cation exchange capacity, soluble protein content, and H+-ATPase activity. Overexpression of AtNHX1 in tobacco significantly improves the K uptake and accumulation. Therefore, leaf K content greatly increased in these transgenic lines in the end. Our findings strongly suggest that AtNHX1 overexpression increased leaf K content by boosting the capacity of enriching K in tobacco roots, thereby advancing the understanding of the function of AtNHX1. NHX1 is closely related to K uptake and accumulation in plants. AtNHX1 -overexpressing tobacco (Nicotiana tabacum) exhibited significantly higher leaf K content than the wild-type tobacco variety K326. The AtNHX1 -overexpressing tobacco has significantly improved root morphology and physiology compared to the wild-type variety K326. AtNHX1 -overexpressing tobacco showed higher V max levels in roots than the wild-type variety K326. Overexpression of AtNHX1 is able to increase leaf potassium content by boosting the ability of enriching potassium in tobacco roots. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
14454408
Volume :
51
Issue :
11
Database :
Academic Search Index
Journal :
Functional Plant Biology
Publication Type :
Academic Journal
Accession number :
180938597
Full Text :
https://doi.org/10.1071/FP24144