STOP1 Regulates LKS1 Transcription and Coordinates K+/NH4+ Balance in Arabidopsis Response to Low-K+ Stress.
Int J Mol Sci
; 23(1)2021 Dec 29.
Article
em En
| MEDLINE
| ID: mdl-35008809
ABSTRACT
Potassium and nitrogen are essential mineral elements for plant growth and development. The protein kinase LKS1/CIPK23 is involved in both K+ and NH4+ uptake in Arabidopsis root. The transcripts of LKS1 can be induced by low K+ (0.1 mM) and high NH4+ (30 mM); however, the molecular mechanism is still unknown. In this study, we isolated the transcription factor STOP1 that positively regulates LKS1 transcription in Arabidopsis responses to both low-K+ and high-NH4+ stresses. STOP1 proteins can directly bind to the LKS1 promoter, promoting its transcription. The stop1 mutants displayed a leaf chlorosis phenotype similar to lks1 mutant when grown on low-K+ and high-NH4+ medium. On the other hand, STOP1 overexpressing plants exhibited a similar tolerant phenotype to LKS1 overexpressing plants. The transcript level of STOP1 was only upregulated by low K+ rather than high NH4+; however, the accumulation of STOP1 protein in the nucleus was required for the upregulation of LKS1 transcripts in both low-K+ and high-NH4+ responses. Our data demonstrate that STOP1 positively regulates LKS1 transcription under low-K+ and high-NH4+ conditions; therefore, LKS1 promotes K+ uptake and inhibits NH4+ uptake. The STOP1/LKS1 pathway plays crucial roles in K+ and NH4+ homeostasis, which coordinates potassium and nitrogen balance in plants in response to external fluctuating nutrient levels.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potássio
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Estresse Fisiológico
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Fatores de Transcrição
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Transcrição Gênica
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Arabidopsis
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Proteínas de Arabidopsis
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Compostos de Amônio
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article