Effects of saline and alkaline stresses in varying temperature regimes on seed germination of <i>Leymus chinensis</i> from the Songnen Grassland of China

Eshghi

et al. 2017

AAS

This study evaluates seed germination and growth of sweet corn under NaCl stress (0, 50, and 100 mM), after exposing the seeds to weak (15 mT) or strong (150 mT) magnetic fields (MF) for different durations (0, 6, 12, and 24 hours). Salinity reduced seed germination and plant growth. MF treatments enhanced rate and percentage of germination and improved plant growth, regardless of salinity. Higher germination rate was obtained by the stronger MF, however, the seedling were more vigorous after priming with 15 mT MF. Proline accumulation was observed in parallel with the loss of plant water content under 100 mM NaCl stress. MF prevented proline accumulation by improving water absorption. Positive correlation between H 2 O 2 accumulation and membrane thermostability (MTI) was found after MF treatments, which revealed that MF primed the plant for salinity by H 2 O 2 signaling. However, over-accumulation of H 2 O 2 after prolonged MF exposure adversely affected MTI under severe salt stress. In conclusion, magnetic priming for 6 hours was suggested for enhancing germination and growth of sweet corn under salt stress. IZVLEČEK INDUKCIJA TOLERANCE NA SOL SLADKE KORUZE S PREDHODNIM OBRAVNAVANJEM SEMEN Z MAGNETNIM POLJEMV raziskavi sta bili ovrednoteni kalitev in rast sladke koruze v razmerah solnega stresa (NaCl; 0, 50, in 100 mM), po izpostavitvi semen šibkemu (15 mT) in močnemu (150 mT) magnetnemu polju (MF) v trajanju 0, 6, 12, in 24 ur. Slanost je zmanjšala kalitev semen in rast rastlin. Obravnavanje z magnetnim poljem je povečalo hitrost in odstotek kalitve ter izboljšalo rast rastlin, ne glede na slanost. Kalitev je bila značilno večja pri obravnavanju z močnejšim magnetnim poljem, kalice so bile bolj vitalne pri obravnavanju z 15 mT MF. Akumulacija prolina je bila opažena sočasno z izgubo vsebnosti vode v razmerah močnega NaCl stresa. Obravnavanje z magnetnim poljem je izboljšalo absorbcijo vode in preprečilo akumulacijo prolina. Pozitivna korelacija med akumulacijo H 2 O 2 in termostabilnostjo membran (MTI), ki je bila opažena po obravnavanju z MF je pokazala, da so bile tako obravnavane rastline odpornejše na slanost preko H 2 O 2 signalizacije. Kljub temu je prekomerna akumulacija H 2 O 2 , kot posledica podaljšane izpostavitve MF, negativno vplivala na MTI v razmerah solnega stresa. Zaključimo lahko, da predobravnavanje semen z magnetnim poljem za 6 ur pospeši nihovo kalitev in rast rastlin v razmerah solnega stresa. Ključne

Section: Discussionmentioning

confidence: 62%

“…Most of the plant species exhibit over-sensitive responses to salt stress at seed germination and early growth stages of seedling (Cuartero et al, 2006). Seed germination may be delayed or prevented by salt stress (Lin et al, 2011). Several strategies can be employed to overcome the adverse effects of salinity.…”

Section: Introductionmentioning

confidence: 99%

Inducing salt tolerance in sweet corn by magnetic priming

Eshghi

et al. 2017

AAS

Grass and Forage Science

“…Tzvel. is a perennial grass species that occurs in the eastern region of the Eurasian steppe, the northern and eastern parts of Mongolia and northern and north‐eastern China (Ma et al ., ; Lin et al ., ). It is an important forage grass that can provide high yields of forage.…”

Section: Introductionmentioning

confidence: 99%

Alleviation of salinity stress on germination of Leymus chinensis seeds by plant growth regulators and nitrogenous compounds under contrasting light/dark conditions

Chen

et al. 2015

The effects of plant growth regulators (PGRs) and nitrogenous compounds on alleviating salinity stress on seed germination of Leymus chinensis in light (12 h light/12 h dark) and dark (24 h dark) conditions were determined in a laboratory experiment. Seed germination was compared at various combinations of salinity and germination-promoting compounds. Seed germination percentages were 57 and 74% under nonsaline conditions in light and dark, respectively, suggesting that germination was light-inhibited. Germination decreased significantly with increasing salinity level in both light and dark conditions, and the reduction was greater in light than in dark at each salinity level. Seed germination percentage decreased to 22 and 7% in light but only to 51 and 27% in dark, in 100 and 200 mM NaCl solutions respectively. The influence of PGRs and nitrogenous compounds in alleviating salinity stress varied with light and salinity condition; e.g., gibberellins (GA 4 + 7 ) significantly increased germination percentages from 22%, 7% and 0Á3% to 47%, 23% and 15% in light at 100, 200 and 300 mM NaCl, respectively, while they showed no effect on germination in darkness. In contrast, sodium nitroprusside and cytokinin significantly increased germination percentage in darkness at all salinity levels, but showed no effect on germination in light at 200 and 300 mM NaCl. Fluridone was very effective in alleviating salinity stress on germination in both light and dark; however, it was lethal to seedlings. Thiourea had no effect in alleviating salinity stress in either light or dark. Thus, alleviation of salinity stress on seed germination of L. chinensis by germination-promoting compounds is strongly dependent on chemicals and light conditions.

“…It is widely distributed in the eastern region of the Eurasian steppes, the Northern and Eastern parts of the People’s Republic of Mongolia, the Inner Mongolia Plateau of China, and the Northeast China Plains (Lin et al, 2011). This grass has an ecological and economical importance because of its high nutritional content (proteins, minerals and carbohydrates).…”

Section: Introductionmentioning

confidence: 99%

“…High salinity in the soil always results in both a delay and a reduction of seed germination. In addition, it can cause a complete inhibition of germination if the saline concentration is high enough (Ungar, 1991; Lin et al, 2011; Lin et al, 2014). However, due to the irregular rainfall in this region, the saline concentration in the soil constantly changes.…”

Section: Introductionmentioning

confidence: 99%

Lemmas induce dormancy but help the seed ofLeymus chinensisto resist drought and salinity conditions in Northeast China

Lin

Shao

Zhang

et al. 2016

PeerJ

Leymus chinensis is a dominant grass in the Songnen grassland of Northern China. The lower germination caused by the presence of lemmas has proved to be an obstacle for the use of the seeds of this plant by humans. However, it is still unknown if the lemmas have other ecological roles such as resisting drought and saline conditions. Three experiments were designed to investigate the ecological roles of the lemmas in Leymus chinensis seeds. The results showed that lemmas significantly improved the amount of water uptake and slowed down the dehydration rate of the seeds under dry conditions. Likewise, the lemmas induced seed dormancy, and removal of the lemmas improved the germination at all temperatures. Although germination percentage of the seeds without lemmas were higher than that of seeds with lemmas under salinity stress, the recovery and total percentage were significantly lower than the seeds with lemmas, especially at 400 mM stress. These results suggest that the lemmas play a vital function in water uptake, dehydration and salt tolerance during the germination stage of the seeds as a response to adverse environmental conditions. Although lemmas showed a dormancy effect, if we want to plant this species in salinity soil in Northeast China, the approach of removing the lemmas by artificial means and improving the seed germination percentage is not feasible.