China
December 15,2 016
Previous studies have revealed that calcium (Ca2+) and hydrogen peroxide (H2O2) are vital secondary messengers in responses to salt stresses in plant. Perennial ryegrass (Lolium perenne L.) is an extensively utilized cool-season grass globally used for forage, turfgrass and soil stabilization. However, little is known about the interplay between Ca2+ and H2O2 signaling in salt-stressed cool-season turfgrass.
A research team led by Prof. FU Jinmin from Wuhan Botanical Garden of Chinese Academy of Sciences investigated the impact of exogenous Ca2+ or H2O2 on the secondary metabolism and oxidative signaling in perennial ryegrass under salt stress. Results have been published in Scientific Reports.
To understand better how Ca2+ and H2O2 signals are integrated to enhance grass acclimation to stress conditions, plants were separated into six groups with four replicates: nutrient solution (control), 300 mM NaCl+7 mM Ca(NO3)2·4H2O, 300 mM NaCl, H2O2, H2O2+300 mM NaCl and 300mM NaCl- Ca2+ (prepared in half-strength Hoagland’s nutrient solution without Ca ion).
Exogenous administration with Ca2+ alleviated the physiological damage induced by salt tress, as shown by the higher turf quality and lower (electrolyteleakage) EL, (malondialdehyde) MDA and H2O2 content, which confirmed that Ca2+ treatment significantly improved the physiological response of stressed plants. External Ca2+ application significantly induced higher K+/ Na+ ratio in roots at eight days treatment leaves. However, a higher Ca2+/ Mg2+ ratio was observed in leaf and root than NaCl-stressed tissues. Ca2+ application under salinity inhibited the decrease of enzyme activity, and greater superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) activity could be obtained when exogenous application of Ca2+ in NaCl solution, which was further confirmed by greater gene transcript abundanceiso enzymes intensity of SOD (3–5), POD (2–5), CAT (1-2), APX (1-5).
Ca2+ and H2O2 signals had one common regulation pattern to maintain reactive oxygen species (ROS) homeostasis in salt-stressed cool-season turfgrass. In addition, the metabolic profiles revealed that sugars and sugar alcohol accounted for 49.5-88.2% of all metabolites accumulation in all treated leaves and roots. However, the accumulation of these sugars and sugar alcohols displayed opposing trends between Ca2+ and H2O2 application in salt-stressed plants. Here, H2O2/ Ca2+-mediated metabolites detected could provide a dataset of common regulatory factors for signaling transduction and salinity acclimation in cool-season turfgrass.
This research was supported by the China-Africa Center for Research and Education, CAS and National Natural Science Foundation of China.
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