StMYB44 negatively regulates phosphate transport by suppressing expression of PHOSPHATE1 in potato.
Phosphorus is an important macronutrient for plant growth, but often deficient in soil. To understand the molecular basis of the complex responses of potato (Solanum tuberosum L.) to phosphate (Pi) deficiency stress, the RNA-Seq approach was taken to identify genes responding to Pi starvation in potato roots. A total of 359 differentially expressed genes were identified, among which the Solanum tuberosum transcription factor gene MYB44 (StMYB44) was found to be down-regulated by Pi starvation. StMYB44 was ubiquitously expressed in potato tissues and organs, and StMYB44 protein was exclusively localized in the nucleus. Overexpression of StMYB44 in potato resulted in lower accumulation of Pi in shoots. Transcriptomic analysis indicated that the abundance of S. tuberosum PHOSPHATE1 (StPHO1), a Pi transport-related gene, was reduced in StMYB44 overexpression lines. In contrast, knock-out of StMYB44 by a CRISPR/Cas9 system failed to increase transcription of StPHO1. Moreover, StMYB44 was found to interact in the nucleus with AtWRKY6, a known Arabidopsis transcription factor directly regulating PHO1 expression, and StWRKY6, indicating that StMYB44 could be a member of the regulatory complex controlling transcription of StPHO1. Taken together, our study demonstrates that StMYB44 negatively regulates Pi transport in potato by suppressing StPHO1 expression.
Department of Agronomy, Purdue University, West Lafayette IN 47907, USA.
Xiangjun
X
Zhou
Department of Agronomy, Purdue University, West Lafayette IN 47907, USA.
Manrong
M
Zha
Department of Agronomy, Purdue University, West Lafayette IN 47907, USA.
Jing
J
Huang
Robert W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, NY 14853, USA.
Li
L
Li
Department of Agronomy, Purdue University, West Lafayette IN 47907, USA.|Department of Soil and Environmental Sciences, University College of Agriculture, University of Sargodha, Pakistan 40100.
Muhammad
M
Imran
Department of Agronomy, Purdue University, West Lafayette IN 47907, USA.
Cankui
C
Zhang
D018506:Gene Expression Regulation, Plant; D028061:Phosphate Transport Proteins / Q000235:genetics* / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D011198:Solanum tuberosum / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D028061:Phosphate Transport Proteins; D010710:Phosphates; D010940:Plant Proteins; D014157:Transcription Factors
Gene expression; PHOSPHATE1; RNA-Seq; StMYB44; phosphate deficiency; potato; protein–protein interaction