Involvement of the plant antioxidative response in the differential growth sensitivity to salinity of leaves vs roots during cell development

TY - JOUR

T1 - Involvement of the plant antioxidative response in the differential growth sensitivity to salinity of leaves vs roots during cell development

AU - Bernstein, Nirit

AU - Shoresh, Michal

AU - Xu, Yan

AU - Huang, Bingru

PY - 2010/10

Y1 - 2010/10

N2 - Sensitivity to salinity varies between plant organs and between cells of different developmental stages within a single organ. The physiological and molecular bases for the differential responses are not known. Exposure of plants to salinity is known to induce formation of reactive oxygen species (ROS), which are involved in damage mechanisms but also in cell growth processes. The objective of this study was to elucidate developmental-stage-specific and organ-specific involvement of oxidative defense in the plant response to salinity in maize (Zea mays L.). Plants were grown in nutrient solution containing 1. mM NaCl (control) or 80. mM NaCl. The oxidative stress response and damage symptoms along the cell developmental gradient in growing and mature tissue of leaves and roots were examined. Unlike leaves, roots did not suffer oxidative damage in either growing or mature cells and demonstrated reduced antioxidant response. This may reflect different requirements of ROS for growth mechanisms of leaf and root cells. In leaves, growing tissue demonstrated higher stimulation of superoxide dismutase (SOD) and ascorbate peroxidase (APX) activity under salinity than mature tissue, whereas mature tissue demonstrated higher stimulation of catalase. These results indicate differential roles for these ROS-scavenging enzymes at different cell developmental stages. Because ROS are required for cell expansion, the higher increase in SOD and APX activities in the growing leaf cells that resulted in reduction of ROS content under salinity could lead to the inhibition of cell growth under salinity.

AB - Sensitivity to salinity varies between plant organs and between cells of different developmental stages within a single organ. The physiological and molecular bases for the differential responses are not known. Exposure of plants to salinity is known to induce formation of reactive oxygen species (ROS), which are involved in damage mechanisms but also in cell growth processes. The objective of this study was to elucidate developmental-stage-specific and organ-specific involvement of oxidative defense in the plant response to salinity in maize (Zea mays L.). Plants were grown in nutrient solution containing 1. mM NaCl (control) or 80. mM NaCl. The oxidative stress response and damage symptoms along the cell developmental gradient in growing and mature tissue of leaves and roots were examined. Unlike leaves, roots did not suffer oxidative damage in either growing or mature cells and demonstrated reduced antioxidant response. This may reflect different requirements of ROS for growth mechanisms of leaf and root cells. In leaves, growing tissue demonstrated higher stimulation of superoxide dismutase (SOD) and ascorbate peroxidase (APX) activity under salinity than mature tissue, whereas mature tissue demonstrated higher stimulation of catalase. These results indicate differential roles for these ROS-scavenging enzymes at different cell developmental stages. Because ROS are required for cell expansion, the higher increase in SOD and APX activities in the growing leaf cells that resulted in reduction of ROS content under salinity could lead to the inhibition of cell growth under salinity.

KW - Antioxidant enzymes

KW - Free radicals

KW - Growing zone

KW - Lipid peroxidation

KW - ROS

KW - Salinity

KW - Zea mays

UR - http://www.scopus.com/inward/record.url?scp=77956178864&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77956178864&partnerID=8YFLogxK

U2 - https://doi.org/10.1016/j.freeradbiomed.2010.06.032

DO - https://doi.org/10.1016/j.freeradbiomed.2010.06.032

M3 - Article

C2 - 20619339

SN - 0891-5849

VL - 49

SP - 1161

EP - 1171

JO - Free Radical Biology and Medicine

JF - Free Radical Biology and Medicine

IS - 7

ER -