A comparative analysis of rhizospheric metaproteome of wheat grown in saline and non-saline soils identifies proteins linked with characteristic functions

Salinity is the major cause of reducing crop yield in wheat, an important staple food crop for food security. Since the rhizosphere microbiome plays an important role in plant growth and development, the present study was conducted to characterize functional metabolic changes in the rhizosphere microbiota of wheat grown under saline and non-saline soils using comparative metaproteomics. In total 1538 and 891 proteins were obtained from wheat rhizosphere from saline and non-saline soils, respectively. The proteins DNA-directed RNA polymerase subunit beta' (48.43%) followed by Leucine-tRNA ligase (4.45%) and translocase subunit SecA (2.69%) were relatively most abundantly present in salt stressed wheat rhizosphere metaproteome. Induced accumulation of proteins related to proline and spermidine biosynthesis was found in saline wheat rhizosphere. Inositol transporter involved in the osmotic balance and HSP90A, a key player to response regulator in stress were present in saline rhizosphere but were absent in non-saline conditions. Among 1410 proteins unique for saline soil, those linked predominantly with the pathways were sphingolipid, phosphinate and phenazine metabolism. The data is available in ProteomeXchange with the identifier PXD015387. The present study extends knowledge about the rhizosphere community functions utilizing a metaproteomic approach in wheat growing under saline conditions and can help in characterizing key proteins that may lead to physiological adaptations of the plants under saline environment.

Automated summary

Salinity is a major factor limiting wheat crop yield. This study used metaproteomics to analyze functional metabolic changes in the rhizosphere microbiota of wheat grown in saline and non-saline soils. The results showed that proteins related to proline and spermidine biosynthesis were induced in the saline wheat rhizosphere, and proteins involved in osmotic balance and stress response were present only in saline conditions. Additionally, unique proteins associated with sphingolipid, phosphinate, and phenazine metabolism were identified in the saline soil. These findings enhance our understanding of the functional characteristics of the rhizosphere microbiota and the physiological adaptations of plants in saline environments.