S-Nitroso-Proteome in Poplar Leaves in Response to Acute Ozone Stress

Abstract

Protein S-nitrosylation, the covalent binding of nitric oxide (NO) to protein cysteine residues, is one of the main mechanisms of NO signaling in plant and animal cells. Using a combination of the biotin switch assay and label-free LC-MS/MS analysis, we revealed the S-nitroso-proteome of the woody model plant Populus x canescens. Under normal conditions, constitutively S-nitrosylated proteins in poplar leaves and calli comprise all aspects of primary and secondary metabolism. Acute ozone fumigation was applied to elicit ROS-mediated changes of the S-nitroso-proteome. This treatment changed the total nitrite and nitrosothiol contents of poplar leaves and affected the homeostasis of 32 S-nitrosylated proteins. Multivariate data analysis revealed that ozone exposure negatively affected the S-nitrosylation status of leaf proteins: 23 proteins were de-nitrosylated and 9 proteins had increased S-nitrosylation content compared to the control. Phenylalanine ammonia-lyase 2 (log2[ozone/control] = −3.6) and caffeic acid O-methyltransferase (−3.4), key enzymes catalyzing important steps in the phenylpropanoid and subsequent lignin biosynthetic pathways, respectively, were de-nitrosylated upon ozone stress. Measuring the in vivo and in vitro phenylalanine ammonia-lyase activity indicated that the increase of the phenylalanine ammonia-lyase activity in response to acute ozone is partly regulated by de-nitrosylation, which might favor a higher metabolic flux through the phenylpropanoid pathway within minutes after ozone exposure.

Knocking Down of Isoprene Emission Modifies the Lipid Matrix of Thylakoid Membranes and Influences the Chloroplast Ultrastructure in Poplar

“…The multivariate data analyses followed the established procedures to analyze MS data as described previously (Ghirardo et al, 2005(Ghirardo et al, , 2012Kreuzwieser et al, 2014;Vanzo et al, 2014;Velikova et al, 2014). The isoprene emission trait was selected as the Y variable for the OPLS analysis by setting NE = 1 and IE = 0.…”

S‐nitrosylation/denitrosylation as a regulatory mechanism of salt stress sensing in sunflower seedlings

“…Interestingly, proteins in the indicated zone showed downregulation in response to GSNO treatment irrespective of salt stress. Vanzo et al () analyzed the abundance of S‐nitrosylated proteins in callus and leaf extracts from poplar and observed enrichment of S‐nitrosylation of several proteins in response to ozone stress. In the recent past, differential modulation of S‐nitrosoproteome of Brassica juncea by low temperature revealed both enhanced S‐nitrosylation of at least nine proteins and denitrosylation of eight proteins (Abat and Deswal ).…”

Tyrosine-Nitrated Proteins: Proteomic and Bioanalytical Aspects

“…In the context of • NO-mediated posttranslational modifications, the small number of detected and reported tyrosine nitrated proteins is in sharp contrast with the much larger number of reported S-nitrosated proteins (37,98); indeed, the 'Snitrosoproteome' has been reported to involve at least 1,000 of proteins (90,98,117).…”