Mitogen-activated protein kinase 6 integrates phosphate and iron responses for indeterminate root growth in Arabidopsis thaliana

• Published in: Planta Vol. 250; no. 4; pp. 1177 - 1189
• Main Authors: López-Bucio, Jesús Salvador, Salmerón-Barrera, Guadalupe Jessica, Ravelo-Ortega, Gustavo, Raya-González, Javier, León, Patricia, de la Cruz, Homero Reyes, Campos-García, Jesús, López-Bucio, José, Guevara-García, Ángel Arturo
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Science + Business Media 01-10-2019; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Agriculture; Arabidopsis; Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Biological Transport; Biomedical and Life Sciences; Cell Division; Ecology; Forestry; Gene expression; Genes, Reporter; Indoleacetic Acids - metabolism; Iron; Iron - metabolism; Kinases; Life Sciences; MAP kinase; Meristem - enzymology; Meristem - genetics; Meristem - growth & development; Meristems; Mitogen-Activated Protein Kinases - genetics; Mitogen-Activated Protein Kinases - metabolism; ORIGINAL ARTICLE; Phosphates - metabolism; Plant growth; Plant Growth Regulators; Plant Roots - enzymology; Plant Roots - genetics; Plant Roots - growth & development; Plant Sciences; Protein kinase; Proteins; Stress, Physiological; Supplements; Low Pi stress; MAPK6; Phosphate/iron balance; Root development
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-019-03212-4

Phosphate (Pi) deficiency induces determinate primary root growth in Arabidopsis through cessation of cell division in the meristem, which is linked to an increased iron (Fe) accumulation. Here, we show that Mitogen-Activated Protein Kinase6 (MPK6) has a role in Arabidopsis primary root growth under low Pi stress. MPK6 activity is induced in roots in response to low Pi, and such induction is enhanced by Fe supplementation, suggesting an MPK6 role in coordinating Pi/Fe balance in mediating root growth. The differentiation of the root meristem induced by low Pi levels correlates with altered expression of auxin-inducible genes and auxin transporter levels via MPK6. Our results indicate a critical role of the MPK6 kinase in coordinating meristem cell activity to Pi and Fe availability for proper primary root growth.