Water stress induces a differential and spatially distributed nitro-oxidative stress response in roots and leaves of Lotus japonicus.
Water stress is one of the most severe problems for plant growth and productivity. Using the legume Lotus japonicus exposed to water stress, a comparative analysis of key components in metabolism of reactive nitrogen and oxygen species (RNS and ROS, respectively) were made. After water stress treatment plants accumulated proline 23 and 10-fold in roots and leaves respectively, compared with well-watered plants. Significant changes in metabolism of RNS and ROS were observed, with an increase in both protein tyrosine nitration and lipid peroxidation, which indicate that water stress induces a nitro-oxidative stress. In roots, ·NO content was increased and S-nitrosoglutathione reductase activity was reduced by 23%, wherein a specific protein nitration pattern was observed. As part of this response, activity of NADPH-generating dehydrogenases was also affected in roots resulting in an increase of the NADPH/NADP(+) ratio. Our results suggest that in comparison with leaves, roots are significantly affected by water stress inducing an increase in proline and NO content which could highlight multiple functions for these metabolites in water stress adaptation, recovery and signaling. Thus, it is proposed that water stress generates a spatial distribution of nitro-oxidative stress with the oxidative stress component being higher in leaves whereas the nitrosative stress component is higher in roots.
Laboratorio de Bioquímica, Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, CP 12900 Montevideo, Uruguay.
Santiago
S
Signorelli
Francisco J
FJ
Corpas
Omar
O
Borsani
Juan B
JB
Barroso
Jorge
J
Monza
D000445:Aldehyde Oxidoreductases / Q000378:metabolism; D015153:Blotting, Western; D003681:Dehydration; D004789:Enzyme Activation; D057075:Enzyme Assays; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation; D000070116:Lotus / Q000201:enzymology / Q000378:metabolism* / Q000502:physiology; D009249:NADP / Q000378:metabolism; D009252:NADPH Dehydrogenase / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress; D010641:Phenotype; D010936:Plant Extracts / Q000032:analysis / Q000378:metabolism; D018515:Plant Leaves / Q000201:enzymology / Q000378:metabolism* / Q000502:physiology; D018517:Plant Roots / Q000201:enzymology / Q000378:metabolism* / Q000502:physiology; D011392:Proline / Q000378:metabolism; D026361:Reactive Nitrogen Species / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D014867:Water / Q000378:metabolism*
D010936:Plant Extracts; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; D014867:Water; D009569:Nitric Oxide; D009249:NADP; D011392:Proline; D006861:Hydrogen Peroxide; D000445:Aldehyde Oxidoreductases; C087006:formaldehyde dehydrogenase, glutathione-independent; D009252:NADPH Dehydrogenase