A diatom gene regulating nitric-oxide signaling and susceptibility to diatom-derived aldehydes

Autor: Chris Bowler, Assaf Vardi, Paul G. Falkowski, Donald J. Hirsh, Clifford J. Kwityn, Kay D. Bidle, Stephanie E.M. Thompson, James A. Callow
Rok vydání: 2008
Předmět:
Zdroj: Current biology : CB. 18(12)
ISSN: 0960-9822
Popis: Summary Diatoms are unicellular phytoplankton accounting for ∼40% of global marine primary productivity [1], yet the molecular mechanisms underlying their ecological success are largely unexplored. We use a functional-genomics approach in the marine diatom Phaeodactylum tricornutum to characterize a novel protein belonging to the widely conserved YqeH subfamily [2] of GTP-binding proteins thought to play a role in ribosome biogenesis [3], sporulation [4], and nitric oxide (NO) generation [5]. Transgenic diatoms overexpressing this gene, designated PtNOA , displayed higher NO production, reduced growth, impaired photosynthetic efficiency, and a reduced ability to adhere to surfaces. A fused YFP-PtNOA protein was plastid localized, distinguishing it from a mitochondria-localized plant ortholog. PtNOA was upregulated in response to the diatom-derived unsaturated aldehyde 2E,4E/Z-decadienal (DD), a molecule previously shown to regulate intercellular signaling, stress surveillance [6], and defense against grazers [7]. Overexpressing cell lines were hypersensitive to sublethal levels of this aldehyde, manifested by altered expression of superoxide dismutase and metacaspases, key components of stress and death pathways [8, 9]. NOA-like sequences were found in diverse oceanic regions, suggesting that a novel NO-based system operates in diatoms and may be widespread in phytoplankton, providing a biological context for NO in the upper ocean [10].
Databáze: OpenAIRE