RESUMEN
Plant health states may influence the distribution of rhizosphere microorganisms, which regulate plant growth and development. In this study, the response of rhizosphere bacteria and fungi of healthy and diseased plants compared to bulk microbes was analyzed using high-throughput sequencing. Plant adaptation strategies of plants under potato virus Y (PVY) infection have been studied from a microbial perspective. The diversity and community structure of bacteria and fungi varied between bulk and rhizosphere soils, but not between healthy and diseased rhizosphere soils. A LEfSe analysis revealed the significant differences between different treatments on bacterial and fungal community compositions and identified Roseiflexaceae, Sphingomonas, and Sphingobium as the bacterial biomarkers of bulk (BCK), healthy rhizosphere (BHS), and diseased rhizosphere (BIS) soils, respectively; Rhodotorula and Ascomycota_unidentified_1_1 were identified as the fungal biomarkers of bulk (FCK) and healthy rhizosphere (FHS) soils. Bacterial networks were found to be more complex and compact than fungal networks and revealed the roles of biomarkers as network keystone taxa. PVY infection further increased the connectedness among microbial taxa to improve rhizosphere microbial community stability and resistance to environmental stress. Additionally, water content (WC) played an apparent influence on bacterial community structure and diversity, and pH showed significant effects on fungal community diversity. WC and pH greatly affected the biomarkers of bacterial rhizosphere communities, whereas the biomarkers of bulk bacterial communities were significantly affected by soil nutrients, especially for Sphingobium. Overall, the rhizosphere microbial community enrichment processes were different between healthy and diseased plants by changing the community compositions and identifying different biomarkers. These findings provide insight into the assemblage of rhizosphere microbial communities and soil physicochemical properties, which contributes to a deeper understanding of the establishment of an artificial core root microbiota to facilitate plant growth and bolstering resistance mechanisms. This knowledge contributes to a deeper understanding of the establishment of an artificial core root microbiota, thereby facilitating plant growth and bolstering resistance mechanisms.
RESUMEN
The effects of high potassium and normal potassium treatments on protein expression in roots of flue-cured tobacco plant HKDN-5 at the seedling stage were analyzed by an unlabeled protein quantification technique. The results showed that 555 proteins were differentially expressed (245 proteins were down-regulated and 310 proteins were up-regulated) in high potassium treatment compared with normal potassium treatment. Differentially expressed proteins were involved in 96 metabolic pathways (42 metabolic pathways, 21 synthetic pathways as well as catabolic pathways, including fatty acid metabolism, phenylpropane biosynthesis, ketone body synthesis and degradation, and butyric acid metabolism. Root processing of high potassium concentrations leads to increases in the synthesis of peroxidase, superoxide dismutase and acyl-coenzyme-A synthetase. Additional proteomic differences observed in tobacco roots grown in high potassium include proteins involved with genetic information processing as well as environmental sensing. Examples include RNA helicase, ABC transporters and large subunit GTPases. These up-regulated differentially expressed proteins function mainly in protein translation, ribosome structure and protein synthesis. This indicates that under high potassium treatment, root protein synthetic processes are accelerated and substance metabolism pathways are enhanced; thus, providing the material and energetic basis for root growth.
