Cross-talk between reactive oxygen species and polyamines in regulation of ion transport across the plasma membrane: implications for plant adaptive responses.
Many stresses are associated with increased accumulation of reactive oxygen species (ROS) and polyamines (PAs). PAs act as ROS scavengers, but export of putrescine and/or PAs to the apoplast and their catabolization by amine oxidases gives rise to H2O2 and other ROS, including hydroxyl radicals ((•)OH). PA catabolization-based signalling in apoplast is implemented in plant development and programmed cell death and in plant responses to a variety of biotic and abiotic stresses. Central to ROS signalling is the induction of Ca(2+) influx across the plasma membrane. Different ion conductances may be activated, depending on ROS, plant species, and tissue. Both H2O2 and (•)OH can activate hyperpolarization-activated Ca(2+)-permeable channels. (•)OH is also able to activate both outward K(+) current and weakly voltage-dependent conductance (ROSIC), with a variable cation-to-anion selectivity and sensitive to a variety of cation and anion channel blockers. Unexpectedly, PAs potentiated (•)OH-induced K(+) efflux in vivo, as well as ROSIC in isolated protoplasts. This synergistic effect is restricted to the mature root zone and is more pronounced in salt-sensitive cultivars compared with salt-tolerant ones. ROS and PAs suppress the activity of some constitutively expressed K(+) and non-selective cation channels. In addition, both (•)OH and PAs activate plasma membrane Ca(2+)-ATPase and affect H(+) pumping. Overall, (•)OH and PAs may provoke a substantial remodelling of cation and anion conductance at the plasma membrane and affect Ca(2+) signalling.
Biomedical Center, University of Colima, Mexico.
Igor
I
Pottosin
Ana María
AM
Velarde-Buendía
Jayakumar
J
Bose
Isaac
I
Zepeda-Jazo
Sergey
S
Shabala
Oxana
O
Dobrovinskaya
D002462:Cell Membrane / Q000378:metabolism*; D017136:Ion Transport; D008564:Membrane Potentials; D018521:Plant Physiological Phenomena; D011073:Polyamines / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*
D011073:Polyamines; D017382:Reactive Oxygen Species
Abiotic stress; P-type ATPase; amine oxidase; apoplast; calcium; hydroxyl radical; hypersensitive response; ion channel; plasma membrane; polyamine; reactive oxygen species; root; stomata.