Antagonistic roles of abscisic acid and cytokinin during response to nitrogen depletion in oleaginous microalga Nannochloropsis oceanica expand the evolutionary breadth of phytohormone function

• DOI: 10.1111/tpj.12615
• Publication Date: 2014-07-15T14:41:30Z
• Authors: Yandu Lu; Danuše Tarkowská; Veronika Turečková; Tingwei Luo; Yi Xin; Jing Li; Qintao Wang; Nianzhi Jiao; Miroslav Strnad; Jian Xu
• Keywords: Plant Physiology

Summary The origin of phytohormones is poorly understood, and their physiological roles in microalgae remain elusive. Genome comparison photosynthetic autotrophic eukaryotes has revealed that the biosynthetic pathways abscisic acid ( ABA ) cytokinins CK s) emerged unicellular algae. While degradation mechanisms broadly algal lineages, complete vascular plant‐type conjugation prior to rise S treptophyta. In microalgae, a set proteins from canonical sensing signaling not essential, but individual components are present, suggesting stepwise recruitment phytohormone components. oleaginous eustigmatophyte N annochloropsis oceanica IMET 1, UHPLC ‐ MS / detected wide array plant hormones, despite profile very distinct flowering plants. Time‐series transcriptional analysis during nitrogen depletion activation pathway antagonistic transcription genes. Correspondingly, level increases while dominant bioactive forms decrease. Moreover, exogenous s stimulate cell‐cycle progression acts as both an growth repressor positive regulator response stresses. presence such functional plant‐like systems sp. suggests much earlier biosynthesis than previously believed, supports yet unknown sensing/signaling may be exploited for microalgal feedstock development.