Isobaric tags for relative and absolute quantification‐based proteomic analysis of Puccinellia tenuiflora inoculated with arbuscular mycorrhizal fungi reveal stress response mechanisms in alkali‐degraded soil

Abstract

Alkali soil is a major abiotic constraint that limits plant distribution and yield in the northeast of China. Puccinellia tenuiflora is considered the most promising grass species for salt‐alkali grassland restoration. However, there is little information on the molecular mechanisms underlying how arbuscular mycorrhizal fungi (AMF) enhances P. tenuiflora stress responses in alkali‐degraded soil. In this study, AMF colonization, growth, photosynthetic pigments, and inorganic ion contents were measured. Isobaric tags for relative and absolute quantification‐based quantitative proteomic technology were employed to identify the differentially abundant proteins in P. tenuiflora seedlings with or without AMF under alkalinity stress. The results showed that AMF colonization increased seedling biomass, photosynthetic pigment contents, and K+/Na+ ratio under alkalinity stress. Moreover, a total of 598 proteins were significantly differentially regulated in P. tenuiflora seedlings after AMF inoculation under alkalinity stress compared with under alkalinity stress alone. The results showed that AMF inoculation significantly improved protein synthesis, reactive oxygen species scavenging, and nitrogen metabolism to promote the biosynthesis of osmotic substances in response to alkalinity stress. In addition, P. tenuiflora seedlings produced more energy to compensate for the energy loss caused by alkalinity stress after AMF inoculation. In conclusion, these findings provide new insights into the physiological mechanisms of the response to alkali‐degraded soil in P. tenuiflora seedlings with AMF and also clarify the role of AMF in the molecular regulation network of P. tenuiflora under alkalinity stress.

Arbuscular mycorrhizal fungi improve the growth and performance in the seedlings of Leymus chinensis under alkali and drought stresses

“…Hence, understanding the positive effect of AMF on this species is crucial for its use in grassland rehabilitation and restoration. Our previous studies showed a good symbiotic relationship between AMF and this species under salt and alkali stresses ( Lin et al, 2017 ; Wang et al, 2019a ; Wang et al, 2019b Wang et al, 2019c ; Yang et al, 2020a ; Yang et al, 2020b ). In the present study, we hypothesized (1) that AMF play an important role in alleviating the inhibitory effect on seedling growth under alkali or drought stress conditions and (2) that the interaction of alkali and drought stresses affects the alleviating effect of AMF in Leymus chinensis seedlings.…”

“…Thiobarbituric acid (0.6%. one mL) was used to extract malondialdehyde (MDA) from fresh shoots (200 mg), and the absorbance was then measured at 600, 532 and 450 nm ( Wang et al, 2019a ; Wang et al, 2019b Wang et al, 2019c ). Proline was extracted with 3% sulfosalicylic acid for 1 h, and the absorbance was measured at 520 nm ( Bates, Waldren & Teare, 1973 ).…”

“…Arbuscular mycorrhizal fungi (AMF) can colonize most terrestrial plants and thereby enhance the growth of host plants and provide external protection in response to abiotic stresses, such as drought, salt and temperature stresses ( Amiri, Nikbakht & Etemadi, 2015 ; Lin et al, 2017 ; Zhang et al, 2020 ). Previous studies have suggested the underlying mechanisms by which AMF improve tolerance to single alkali or drought stress in host plants, including the promotion of water and nutrient uptake ( Kumar et al, 2015 ), improvement of soil aggregate stability ( Quiroga et al, 2018 ), and enhancement of osmotic adjustment ( Wang et al, 2019a ; Wang et al, 2019b ; Wang et al, 2019c ; Yang et al, 2020a ; Yang et al, 2020b ). However, the interactive effect of alkali and drought stresses on the relationship between host plants and AMF is still poorly understood.…”

Proteomic analysis revealed modulations of carbon and nitrogen by arbuscular mycorrhizal fungi associated with the halophyte Suaeda salsa in a moderately saline environment

“…NaHCO 3 ) and salt-tolerance plant E. angustifolia under salt stress (300 mM NaCl) (Jia et al, 2019;Wang et al, 2019). The inconsistency may imply that the regulation of AMF on these pathways in halophytes differs with the environment, that is, between under the moderate and high salinity stress.…”

“…Recently, proteomics technologies have been employed to identify the proteins inducted by AMF, and reveal the mechanisms of AM symbiosis tolerating abiotic stresses at the protein level (Bai et al, 2019;Wu et al, 2019). For instance, the AMF Rhizophagus intraradices can significantly improve protein synthesis, nitrogen metabolism and ROS scavenging to boost osmotic substance biosynthesis and response to alkaline stress in a salt-alkali grass Puccinellia tenuiflora by proteomics (Wang et al, 2019) S. salsa is widely distributed in Asia, and grows in littoral and inland salt soils in China, and the species is a leaf-succulent halophytic herb that is able to accumulate salts in shoots and can be used to restore salty soils (Song & Wang, 2015). Its favorable salt concentration is from 100 to 300 mM NaCl for vigorous growth (Qiu et al, 2007).…”