title: Nitric oxide accumulation and protein tyrosine nitration as a rapid and long distance signalling response to salt stress in sunflower seedlings.
abstract: Sensing of salt stress by sunflower seedlings accompanies temporal and spatial modulation of intracellular nitric oxide (NO) accumulation and protein tyrosine nitration as markers of nitrosative stress. Employing a novel NO-specific probe for NO localization (a copper derivative of 4-methoxy-2-(1H-naphtho(2,3-d)imidazol-2-yl)phenol; MNIP-Cu) synthesized in author's laboratory, immunological analysis of tyrosine nitrated proteins by confocal laser scanning microscopy (CLSM) and Western blot analysis, these rapid signalling events have been investigated. MNIP-Cu reveals the distribution of NO in whole seedlings. Preferential and enhanced NO localization around oil bodies (OBs) in cotyledons within 48 h of salt-stressed seedlings exhibits rapid transport of nitrosative stress signal from roots to the cotyledons. Immunological analysis reveals enhanced gradient of tyrosine nitrated proteins in salt-stressed roots from tip to the differentiating zone and from columella to the deep-seated cells. Western blot analysis shows that at least eight major cytosolic proteins exhibit enhanced tyrosine nitration in seedling roots in response to salt stress. Present observations provide strong evidence for rapid NO accumulation in salt stressed sunflower seedling roots and cotyledons and its impact on enhanced tyrosine nitration of cytosolic and OB proteins, as a mechanism to provide longevity to OBs for seedling survival under the salt stress.
authors: Laboratory of Plant Physiology and Biochemistry, Department of Botany, University of Delhi, Delhi 110007, India.
authors: Anisha
authors: A
authors: David
authors: Laboratory of Plant Physiology and Biochemistry, Department of Botany, University of Delhi, Delhi 110007, India.
authors: Sunita
authors: S
authors: Yadav
authors: Institute of Molecular Cell Biology, University of Bonn, Bonn, Germany.
authors: František
authors: F
authors: Baluška
authors: Laboratory of Plant Physiology and Biochemistry, Department of Botany, University of Delhi, Delhi 110007, India. Electronic address: bhatlasc@gmail.com.
authors: Satish Chander
authors: SC
authors: Bhatla
keywords: Nitric oxide; Oil bodies; Protein tyrosine nitration; Salt stress; Sunflower