NO Promotes Seed Germination and Seedling Growth Under High Salt May Depend on EIN3 Protein in Arabidopsis

Abstract

The gas molecule nitric oxide (NO) can cooperate with ethylene to tightly modulate plant growth and stress responses. One of the mechanism of their crosstalk is that NO is able to activate ethylene biosynthesis, possibly through post-translational modification of key enzymes such as ACC synthase and oxidase by S-nitrosylation. In this paper, we focus on the crosstalk of NO with ethylene signaling transduction transcription factor EIN3 (Ethylene Insensitive 3) and downstream gene expression in alleviating germination inhibition and growth damage induced by high salt. The Arabidopsis lines affected in ethylene signaling (ein3eil1) and NO biosynthesis (nia1nia2) were employed to compare with the wild-type Col-0 and overexpressing line EIN3ox. Firstly, the obviously inhibited germination, greater ratio of bleached leaves and enhanced electrolyte leakage were found in ein3eil1 and nia1nia2 lines than in Col-0 plants upon high salinity. However, the line EIN3ox obtained a notably elevated ability to germinate and improved seedling resistance. The experiment with SNP alone or plus high salt mostly enhanced the expression of EIN3 transcripts, compared with ACO4 and ACS2. The western blot and transcript analysis found that high-salt-induced EIN3 stabilization and EIN3 transcripts were largely attenuated in the NO biogenesis mutant nia1nia2 plants than in Col-0 ones. This observation was confirmed by simulation experiments with NO scavenger cPTIO to block NO emission. Taken together, our study provides insights that NO promotes seed germination and seedlings growth under salinity may depend on EIN3 protein.

Ethylene Signaling Modulates Cortical Microtubule Reassembly in Response to Salt Stress

“…S4A and S4B). An additional method 196 was used for quantification of the total microtubule length per unit surface area (Fujita 197 et al, 2013 salt stress (Asensi-Fabado et al, 2012;Li et al, 2016). The mutant ein3eil1 is 208 hypersensitive to NaCl treatment (Peng et al, 2014 signaling-inhibited hypocotyl cell elongation in darkness (Sun et al, 2015;Ma et al, 256 2016 Similar to other reports, we found that activation of ethylene signaling greatly alters 374 organization and stability of cortical microtubules in hypocotyl cells (Sun et al, 2015; 375 Ma et al, 2016Ma et al, , 2018.…”

Nitrate Promotes Germination Under Inhibition by NaCl or High Concentration of Glucose

“…In contrast, ethylene enhances the localization of COP1 to the nucleus to promote germination [ 36 ]. In addition, Li et al (2015) reported that NO managed to alleviate germination inhibition induced by salt stress, by enhancing ethylene signaling [ 39 ]. In many plants, NO can be produced from nitrate by nitrate reductase (NR) [ 31 , 40 ].…”

Nitric Oxide Overproduction by cue1 Mutants Differs on Developmental Stages and Growth Conditions

“…High salinity delays germination and impairs seedling establishment [52]. Endogenous NO is increased when plants are exposed to salt stress and might act as an antioxidant by quenching the ROS produced in response to salinity [53][54][55][56].…”