Phosphate homeostasis and root development in Arabidopsis are synchronized by the zinc finger transcription factor ZAT6.
Phosphorus availability is limited in many natural ecosystems. Plants adapt to phosphate (Pi) deficiency by complex molecular processes. There is growing evidence suggesting that transcription factors are key components in the regulation of these processes. In this study, we characterized the function of ZAT6 (zinc finger of Arabidopsis 6), a cysteine-2/histidine-2 zinc finger transcription factor that is responsive to Pi stress. ZAT6 is induced during Pi starvation and localizes to the nucleus. While the RNAi suppression of ZAT6 appeared to be lethal, its overexpression affects root development and retards seedling growth as a result of decreased Pi acquisition. The ZAT6 overexpression also resulted in altered root architecture of older plants, with consequent changes in Pi acquisition. These results indicate that ZAT6 regulates root development independent of the Pi status of the plant, thereby influencing Pi acquisition and homeostasis. In addition, the expression of several Pi starvation-responsive genes was decreased in ZAT6 overexpressing plants, thereby confirming the role of ZAT6 in regulating Pi homeostasis. This study thus indicates that ZAT6 is a repressor of primary root growth and regulates Pi homeostasis through the control of root architecture. To our knowledge, ZAT6 is the first cysteine-2/histidine-2 zinc finger transcription factor reported to regulate root development and nutrient stress responses.
Devaiah
Ballachanda N
BN
Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907-1165, USA.
Nagarajan
Vinay K
VK
Raghothama
Kashchandra G
KG
D000135:Acid Phosphatase / Q000378:metabolism; D000222:Adaptation, Physiological / Q000235:genetics; D000872:Anthocyanins / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D005804:Genes, Lethal; D006706:Homeostasis / Q000502:physiology; D008969:Molecular Sequence Data; D010710:Phosphates / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development*; D034622:RNA Interference; D036226:Seedlings / Q000254:growth & development; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D000872:Anthocyanins; D029681:Arabidopsis Proteins; D010710:Phosphates; D014157:Transcription Factors; C525378:ZAT6 protein, Arabidopsis; D000135:Acid Phosphatase