Modulation of Ion Transport Across Plant Membranes by Polyamines: Understanding Specific Modes of Action Under Stress

Abstract

This work critically discusses the direct and indirect effects of natural polyamines and their catabolites such as reactive oxygen species and γ-aminobutyric acid on the activity of key plant ion-transporting proteins such as plasma membrane H+ and Ca2+ ATPases and K+-selective and cation channels in the plasma membrane and tonoplast, in the context of their involvement in stress responses. Docking analysis predicts a distinct binding for putrescine and longer polyamines within the pore of the vacuolar TPC1/SV channel, one of the key determinants of the cell ionic homeostasis and signaling under stress conditions, and an additional site for spermine, which overlaps with the cytosolic regulatory Ca2+-binding site. Several unresolved problems are summarized, including the correct estimates of the subcellular levels of polyamines and their catabolites, their unexplored effects on nucleotide-gated and glutamate receptor channels of cell membranes and Ca2+-permeable and K+-selective channels in the membranes of plant mitochondria and chloroplasts, and pleiotropic mechanisms of polyamines’ action on H+ and Ca2+ pumps.

Plant Growth Regulators Application Enhance Tolerance to Salinity and Benefit the Halophyte Plantago coronopus in Saline Agriculture

“…Al-Hassan et al [ 34 ] concluded that family Plantaginaceae have a “constitutive mechanism” of tolerance in which the transport of Na + and Cl − ions (inorganic osmolytes) to the leaves and compartmentalization in the vacuole, contribute to cellular osmotic balance, and increase antioxidant metabolism under saline stress [ 34 , 36 ]. Polyamines are related to ionic transport through at membrane thylakoid, tonoplast, and plasma membranes [ 52 , 62 , 63 ]. Pottosin and Shabala showed that exogenous PAs application (0.1–1 mM) activated Ca 2+ efflux, net H + fluxes, and activated H + -ATPase pump under stress, but all these experiments were realized in the roots of glycophyte seedlings [ 52 , 62 , 63 ].…”

“…Polyamines are related to ionic transport through at membrane thylakoid, tonoplast, and plasma membranes [ 52 , 62 , 63 ]. Pottosin and Shabala showed that exogenous PAs application (0.1–1 mM) activated Ca 2+ efflux, net H + fluxes, and activated H + -ATPase pump under stress, but all these experiments were realized in the roots of glycophyte seedlings [ 52 , 62 , 63 ]. There are no studies on the application of PAs in halophytes on membrane ion channels.…”

Response Mechanisms of Plants Under Saline-Alkali Stress

“…Xu et al (2019) also reported that GABA can reduce the Na + /K + ratio by inducing polyamine generation to enhance salinity-alkalinity stress tolerance in muskmelon. Polyamines were reported to assist in the movement and sequestration of Na + from the cytoplasm to the vacuole and affect K + flux by amending outward-and inward-rectifying K + channels in guard cells and root cells (Pál et al, 2015;Pottosin et al, 2020). Moreover, the application of plant growth-promoting rhizobacteria showed an enhanced capacity to counteract salinealkaline stress in Chrysanthemum plants, which can modify cellular abscisic acid levels, inhibit net K + efflux and concurrently induce net Na + efflux by modulating several Na + /H + and K + antiporters/channels (Zhou et al, 2017).…”

Enzymatic Spermine Metabolites Induce Apoptosis Associated with Increase of p53, caspase-3 and miR-34a in Both Neuroblastoma Cells, SJNKP and the N-Myc-Amplified Form IMR5

“…Many findings have demonstrated the important properties of these polycations. Among such properties, polyamines appear to take part in the control of the translation elongation procedure through the Ser/Thr kinases implicated in the phosphorylation of translation elongation factors process, in the control of ion channels gating and in the regulation of oxidative processes [20][21][22][23][24][25]. Moreover, these natural organic compounds are able to control gene expression by modifying the DNA and RNA structure.…”