Kun-Hsiang Liu, Andrew Diener, Ziwei Lin, Cong Liu, Jen Sheen. Primary nitrate responses mediated by calcium signalling and diverse protein phosphorylation

Primary nitrate responses mediated by calcium signalling and diverse protein phosphorylation

Kun-Hsiang Liu, Andrew Diener, Ziwei Lin, Cong Liu, Jen Sheen

Journal of Experimental Botany

DOI:10.1093/jxb/eraa047

Abstract:Nitrate, the major source of inorganic nitrogen to plants, is a critical signal controlling nutrient transport, assimilation and adaptive growth responses throughout the plant. Understanding how plants perceive nitrate and how this perception is transduced into responses that optimize growth are important for the rational improvement of crop productivity and mitigation of pollution from use of fertilizers. This review highlights recent findings that reveal key roles of cytosolic-nuclear calcium signalling and dynamic protein phosphorylation via diverse mechanisms in the primary nitrate responses (PNR). Nitrate-triggered calcium signatures as well as the critical functions of subgroup III calcium-sensor protein kinases, a specific protein phosphatase 2C, and RNA polymerase II C-terminal domain phosphatase-like 3 are discussed. Moreover, genome-wide meta-analysis of nitrate-regulated genes encoding candidate protein kinases and phosphatases for modulating critical phosphorylation events in the PNR are elaborated. We also consider how phosphoproteomics approaches can contribute to the identification of putative regulatory protein kinases in the PNR. Exploring and integrating experimental strategies, new methodologies, and comprehensive datasets will further advance our understanding of the molecular and cellular mechanisms underlying the complex regulatory processes in the PNR.