Root-associated microbiota drive phytoremediation strategies to lead of Sonchus Asper (L.) Hill as revealed by intercropping-induced modifications of the rhizosphere microbiome

Intercropping or assistant endophytes promote phytoremediation capacities of hyperaccumulators and enhance their tolerance to heavy metal (HM) stress. Findings from a previous study showed that intercropping the hyperaccumulator Sonchus asper (L.) Hill grown in HM-contaminated soils with maize improved the remediating properties and indicated an excluder-to-hyperaccumulator switched mode of action towards lead. In the current study, RNA-Seq analysis was conducted on Sonchus roots grown under intercropping or monoculture systems to explore the molecular events underlying this shift in lead sequestering strategy. The findings showed that intercropping only slightly affects S. asper transcriptome but significantly affects expression of root-associated microbial genomes. Further, intercropping triggers significant reshaping of endophytic communities associated with a ‘root-to-shoot’ transition of lead sequestration and improved phytoremediation capacities of S. asper. These findings indicate that accumulator activities of a weed are partially attributed to the root-associated microbiota, and a complex network of plant–microbe-plant interactions shapes the phytoremediation potential of S. asper. Analysis showed that intercropping may significantly change the structure of root-associated communities resulting in novel remediation properties, thus providing a basis for improving phytoremediation practices to restore contaminated soils.

Morphology and Molecular Characteristics of Alternaria sonchi Causing Brown Leaf Spot on Sonchus asper in Korea

During a disease survey on weeds and minor cultivated crops in Korea, a brown leaf spot disease was observed on Sonchus asper. Leaf lesions were round or irregular in shape, and grayish brown to brown with a purple margin. In severe infection, lesions enlarged and coalesced, resulting in blighting of the leaves. The isolates from these leaf lesions were identified as Alternaira sonchi based on morphological characteristics and phylogenetic analyses of Internal transcribed spacer region, Alternaria allergen a1, glyceraldehyde 3-phosphate dehydrogenase, RNA polymerase II, and translation elongation factor genes. This study provides a comprehensive description of the morphological characteristics and phylogenetical traits of A. sonchi causing brown leaf spot on S. asper in Korea.

A cytomorphological investigation of three species of the genus Sonchus L. (Asterales: Asteraceae) from Punjab, India

Three species of the genus Sonchus L. (Sonchus asper, S. oleraceus and S. wightianus) were collected from the Malwa region of Punjab during 2019 to 2020. These species were studied for cytomorphological variations. The species under investigation were identified based on their morphological descriptions. Sonchus asper (L.) Hill and Sonchus wightianus DC. possess the same number of chromosomes (2n=2x=18) whereas Sonchus oleraceus (L.) L. is tetraploid with 2n=4x=32 chromosomes. Chromosome number of S. wightianus (2n=2x=18) was worked out for the first time from the state of Punjab. Sonchus olereceus has larger pollens than S. asper and S. wightianus. This study will be useful for researchers, taxonomists and cytologists for accurate identification of these three species.

Intercropping-induced shifts in root microbiota promote lead phytoremediation properties of Sonchus Asper

Intercropping or assistant-endophytes has been proven to promote phytoremediation capacities of hyperaccumulators and to enhance their tolerance to heavy metals (HM) stress. We initially showed that intercropping with maize improved the remediating properties of the hyperaccumulator Sonchus asper (L.) Hill grown in HM contaminated soils, accompanied by an excluder - to- hyperaccumulator switched mode of action towards lead. To characterize molecular events underlying this shift in lead extraction strategy, we conducted an RNA-Seq analysis on Sonchus roots grown in intercropping or monoculture. We show that intercropping only slightly affects the S. asper transcriptome, but dramatically impacts the expression of root associated microbial genomes. Further, intercropping triggers a severe reshaping of endophytic communities which accompanies a “root-to-shoot” transition of lead sequestration and improved phytoremediation capacities of S. asper. This study provides the clue that a unitive network of plant- microbial -plant interactions may participate to the phytoremediation abilities of hyperaccumulator plants and paves the path for innovative cultural practices aiming to cure polluted soils.

Antibacterial and Antibiofilm Effects Extracts From Elaeagnus Angustifolia,satureja Montana, Quercus Brantii, Tragopogon Dubius, Sonchus Asper, on the P.aeruginosa and S.aureus

Background: Due to the increase in microbial resistance worldwide and the adverse effects of chemical drugs, the study of antimicrobial compounds in plant extracts as a new source of medicine can be effective in reducing or solving this problem. The purpose of this study antibacterial and antibiofilm effects extracts from Elaeagnus angustifolia,satureja montana, Quercus brantii,Tragopogon dubius,Sonchus asper, on the P.aeruginosa and S.aureus Methods: In this cross-sectional descriptive-analytical study, the study population is plants collected in Isfahan and Shahrekord and Pseudomonas and S.aureus bacteria isolated from clinical samples and standard strains. The sampling method was improbably simple and 120g was collected from each of the 9 plants and extracted by massage method. For the qualitative evaluation of antimicrobial properties, you used the agar well diffusion method and for quantitative evaluation of antimicrobial properties, you used the plate microtiter method. To evaluate the anti-biofilm properties, plate microtiter method, and staining by violet crystal were used. Results: Based on the findings of this study and the study of MBC and MIC of the mentioned plant extracts, it can be said that the best antibacterial effect on all studied strains belongs to the plant extracts of Quercus brantii, Elaeagnus angustifolia, satureja montana, Tragopogon dubius, and Sonchus asper, respectively. Among them, Quercus brantii extract has the best effect on all 4 strains. Also, in the study of anti-biofilm properties, it was observed that the Quercus brantii, satureja montana, and Elaeagnus angustifolia plant extracts had an anti-biofilm effect. Among them, respectively, the most belonging to the Quercus brantii, and the two extracts of Tragopogon dubius, and Sonchus asper do not have good anti-biofilm properties.Conclusions: According to the results of this study on the antimicrobial and antifouling properties of these extracts, it is possible to use this plant in the future with more studies and more work on these plants.