Contribution of Rhizobium–Legume Symbiosis in Salt Stress Tolerance in Medicago truncatula Evaluated through Photosynthesis, Antioxidant Enzymes, and Compatible Solutes Accumulation

Annie Irshad, Rana Naveed Ur Rehman, Muhammad Mohsin Abrar, Qudsia Saeed, Rahat Sharif and Tianming Hu
Additional contact information
Annie Irshad: College of Grassland Agriculture, Northwest A&F University, Yangling 712100, China
Rana Naveed Ur Rehman: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, China
Muhammad Mohsin Abrar: National Engineering Laboratory for Improving Quality of Arable Land, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
Qudsia Saeed: College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China
Rahat Sharif: College of Horticulture and Plant Protection, Yangzhou University, 48 Wenhui East Road, Yangzhou 225009, China
Tianming Hu: College of Grassland Agriculture, Northwest A&F University, Yangling 712100, China

Sustainability, 2021, vol. 13, issue 6, 1-21

Abstract: The effects of salt stress on the growth, nodulation, and nitrogen (N) fixation of legumes are well known, but the relationship between symbiotic nitrogen fixation (SNF) driven by rhizobium–legume symbiosis and salt tolerance in Medicago truncatula is not well studied. The effects of the active nodulation process on salt stress tolerance of Medicago truncatula were evaluated by quantifying the compatible solutes, soluble sugars, and antioxidants enzymes, as well as growth and survival rate of plants. Eight weeks old plants, divided in three groups: (i) no nodules (NN), (ii) inactive nodules (IN), and (iii) active nodules (AN), were exposed to 150 mM of NaCl salt stress for 0, 8, 16, 24, 32, 40, and 48 h in hydroponic system. AN plants showed a higher survival rate (30.83% and 38.35%), chlorophyll contents (37.18% and 44.51%), and photosynthesis compared to IN and NN plants, respectively. Improved salt tolerance in AN plants was linked with higher activities of enzymatic and nonenzymatic antioxidants and higher K + (20.45% and 39.21%) and lower Na + accumulations (17.54% and 24.51%) when compared with IN and NN plants, respectively. Additionally, higher generation of reactive oxygen species (ROS) was indicative of salt stress, causing membrane damage as revealed by higher electrolyte leakage and lipid peroxidation. All such effects were significantly ameliorated in AN plants, showing higher compatible solutes (proline, free amino acids, glycine betaine, soluble sugars, and proteins) and maintaining higher relative water contents (61.34%). This study advocates positive role of Rhizobium meliloti inoculation against salt stress through upregulation of antioxidant system and a higher concentration of compatible solutes.

Keywords: Medicago truncatula; antioxidant enzymes; oxidative damage; salt stress; active nodulation; osmolyte accumulation (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2021
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2071-1050/13/6/3369/pdf (application/pdf)
https://www.mdpi.com/2071-1050/13/6/3369/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jsusta:v:13:y:2021:i:6:p:3369-:d:519906

Access Statistics for this article

Sustainability is currently edited by Ms. Alexandra Wu

More articles in Sustainability from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().