title: The protein kinase SnRK2.6 mediates the regulation of sucrose metabolism and plant growth in Arabidopsis.
abstract: In higher plants, three subfamilies of sucrose nonfermenting-1 (Snf1)-related protein kinases have evolved. While the Snf1-related protein kinase 1 (SnRK1) subfamily has been shown to share pivotal roles with the orthologous yeast Snf1 and mammalian AMP-activated protein kinase in modulating energy and metabolic homeostasis, the functional significance of the two plant-specific subfamilies SnRK2 and SnRK3 in these critical processes is poorly understood. We show here that SnRK2.6, previously identified as crucial in the control of stomatal aperture by abscisic acid (ABA), has a broad expression pattern and participates in the regulation of plant primary metabolism. Inactivation of this gene reduced oil synthesis in Arabidopsis (Arabidopsis thaliana) seeds, whereas its overexpression increased Suc synthesis and fatty acid desaturation in the leaves. Notably, the metabolic alterations in the SnRK2.6 overexpressors were accompanied by amelioration of those physiological processes that require high levels of carbon and energy input, such as plant growth and seed production. However, the mechanisms underlying these functionalities could not be solely attributed to the role of SnRK2.6 as a positive regulator of ABA signaling, although we demonstrate that this kinase confers ABA hypersensitivity during seedling growth. Collectively, our results suggest that SnRK2.6 mediates hormonal and metabolic regulation of plant growth and development and that, besides the SnRK1 kinases, SnRK2.6 is also implicated in the regulation of metabolic homeostasis in plants.
authors.affiliation: Dow AgroSciences LLC, Indianapolis, Indiana 46268, USA. zzheng@dow.com
authors.forename: Zhifu
authors.initials: Z
authors.lastname: Zheng
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Xu
authors.forename: Rodney A
authors.initials: RA
authors.lastname: Crosley
authors.forename: Scott A
authors.initials: SA
authors.lastname: Greenwalt
authors.forename: Yuejin
authors.initials: Y
authors.lastname: Sun
authors.forename: Beth
authors.initials: B
authors.lastname: Blakeslee
authors.forename: Lizhen
authors.initials: L
authors.lastname: Wang
authors.forename: Weiting
authors.initials: W
authors.lastname: Ni
authors.forename: Megan S
authors.initials: MS
authors.lastname: Sopko
authors.forename: Chenglin
authors.initials: C
authors.lastname: Yao
authors.forename: Kerrm
authors.initials: K
authors.lastname: Yau
authors.forename: Stephanie
authors.initials: S
authors.lastname: Burton
authors.forename: Meibao
authors.initials: M
authors.lastname: Zhuang
authors.forename: David G
authors.initials: DG
authors.lastname: McCaskill
authors.forename: Daniel
authors.initials: D
authors.lastname: Gachotte
authors.forename: Mark
authors.initials: M
authors.lastname: Thompson
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Greene
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004734:Energy Metabolism; D044943:Fatty Acid Desaturases / Q000378:metabolism; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D018525:Germination; D009029:Mosaic Viruses; D018515:Plant Leaves / Q000378:metabolism; D010938:Plant Oils / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D036226:Seedlings / Q000254:growth & development; D012639:Seeds / Q000254:growth & development / Q000378:metabolism*; D013395:Sucrose / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D010938:Plant Oils; C492978:SnRK2 protein, Arabidopsis; D013395:Sucrose; D000040:Abscisic Acid; D044943:Fatty Acid Desaturases; D017346:Protein Serine-Threonine Kinases