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MYB77 regulates high‐affinity potassium uptake by promoting expression of HAK5
Author(s) -
Feng Cuizhu,
Luo Yunxin,
Wang Pengdan,
Gilliham Matthew,
Long Yu
Publication year - 2021
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.17589
Subject(s) - mutant , arabidopsis , transcription factor , chlorosis , phenotype , microbiology and biotechnology , biology , transporter , potassium , chemistry , biochemistry , botany , gene , organic chemistry
Summary In Arabidopsis, the high‐affinity K + transporter HAK5 is the major pathway for root K + uptake when below 100 µM; HAK5 responds to Low‐K + (LK) stress by strongly and rapidly increasing its expression during K + ‐deficiency. Therefore, positive regulators of HAK5 expression have the potential to improve K + uptake under LK. Here, we show that mutants of the transcription factor MYB77 share a LK‐induced leaf chlorosis phenotype, lower K + content, and lower Rb + uptake of the hak5 mutant, but not the shorter root growth, and that overexpression of MYB77 enhanced K + uptake and improved tolerance to LK stress. Furthermore, we demonstrated that MYB77 positively regulates the expression of HAK5 , by binding to the HAK5 promoter and enhances high‐affinity K + uptake of roots. As such, our results reveal a novel pathway for enhancing HAK5 expression under LK stress, and provides a candidate for increasing the tolerance of plants to LK.