Effect of leaf damage on chlorophyll fluorescence parameters of Eupatorium adenophorum and its genera

Eupatorium adenophorum has a serious impact on agriculture and biodiversity in China. Chlorophyll fluorescence parameters of E. adenophorum and its genera were investigated after leaf damage treatments. The results showed that the changes of chlorophyll fluorescence parameters were greatly affected by the treatment methods and species. The changes of chlorophyll fluorescence parameters of E. adenophorum and E. lindleyanum after insect feeding were significantly greater than those after simulated insect feeding. Compared with E. lindleyanum, E. adenophorum had lower LEF, higher Phi2 and PhiNPQ after damage. Therefore, E. adenophorum had a higher defense ability against insect food damage compared with E. lindleyanum.

COMPARATIVE STUDY OF POLYPHENOL, FLAVONOID, AND ANTIOXIDANT ACTIVITY OF VARIOUS MEDICINAL PLANTS COLLECTED FROM DIFFERENT ALTITUDES

Objectives: The main aim of this investigation is to explore the folklore medicinal flora located at Terai and the lesser Himalayan region of Nepal and has a comparative study on phenol, flavonoid, and antioxidant activity that would bring forth a factual basis for its use in the traditional therapy of various health ailments. Methods: Folin-Ciocalteu and Colorimetric aluminum chloride methods were used for the estimation of total polyphenolic and flavonoid content, respectively. Moreover, antioxidant activity was determined by DPPH radical scavenging activity. Results: Among 21 plants collected, Artemesia vulgaris depicted higher (53±0.03 mg GAE/g) and Mimosa pudica (3.7±0.04 mg GAE/g) depicted lower phenolic content whereas the highest flavonoid content is observed in Syzygium cumini and the lowest value in Mentha piperita. Almost all the collected specimen demonstrated antioxidant activity, among which Eupatorium adenophorum and Rhododendron anthopogon demonstrated lower and higher antioxidant activity, respectively. Moreover, phenol and flavonoid content showed a weak correlation with the antioxidant activity indicating the major antioxidant to be different compounds other than phenols or flavonoids. Conclusion: The present study confirms the antioxidant activity of the collected plant specimen and defends its ethnobiological use as a possible natural antioxidant. Furthermore, the result of antioxidant properties encourages their application in medicinal health, functional food, and biopharmaceutics.

Metabolomics Reveals the Allelopathic Potential of the Invasive Plant Eupatorium adenophorum

Phytotoxic chemicals produced by alien invasive plants exert inhibitory effects on native species to facilitate their invasiveness. The allelopathic process of invaders has been hypothesized as the “Novel Weapon Hypothesis”. However, this hypothesis has been controversial for decades due to lack of molecular evidence, and the underlying mechanism of allelopathy still remains ambiguous. Herein, we explore the allelopathic mechanisms of Eupatorium adenophorum, a world-widely spread noxious weed, by the methods of laboratory bioassay and metabolomics analyses in the recipient plant, Arabidopsis thaliana. The bioassay revealed significant phytotoxicity of E. adenophorum extracts. A total of 234 metabolites in A. thaliana were detected by Gas Chromatographic−Mass Spectrometric analysis. There were 48, 99 and 94 impacted metabolites in A. thaliana treated by 50, 25 and 12.5% aqueous extracts compared to control. When mapping all the impacted metabolites to the biological pathways in the KEGG (Kyoto Encyclopedia of Genes and Genomes) database, we found mineral absorption, ABC transporters, amino acid biosynthesis, metabolic pathways and biosynthesis of plant secondary metabolites were mainly impacted. Synthesized with partial least-squares discriminate analysis (PLS-DA) results of metabolic profiles in A. thaliana, we found that citrate cycle was suppressed, metabolism of amino acids was disordered and phosphate absorption was inhibited. Subsequent investigation demonstrated that the phosphorus content in A. thaliana tissues exposed in allelopathic extracts was much lower, indicating inhibition of phosphate uptake. Our study revealed by metabolomics approaches that E. adenophorum is an allelopathic species.

Allelopathic plants 29: Eupatorium adenophorum Sprengel

Eupatorium adenophorum is worldwide-spread invasive plant. This review focussed on unique metabolite, Euptox A, released by this plant and its importance in invasion, use and control. Based on previous literature, it is concluded that the mechanism of the invader’s success has a close relationship with a special compound, Euptox A. Its release and degradation mostly determines the spread of E. adenophorum. Besides, the control and use of this invasive species should consider the toxicity of Euptox A. This review suggests that the secondary metabolite, Euptox A, might be a key in controlling and using this invasive plant. This review will increase our knowledge of the role of a natural chemical in biological invasion.

STUDIES ON THE WEED FLORA OF AGASTYAMUNI BLOCK, RUDRAPRAYAG DISTRICT, UTTARAKHAND

Weed commonly called ‘khar- kabad’ in Uttarakhand or ‘kharpatvar’ in India, and is one of the major biological constraints that limits crop productivity. The present communication pertains to survey and inventory of weed flora in Agastyamuni block of district Rudraprayag, Uttarakhand. The study was based on extensive and intensive field survey made during July 2018 to October 2019. During the study period the authors have reported a total 312 species belonging to 188 genera and 54 families from dicots, monocots and pteridophyta. Asteraceae was found to be the most dominant family followed by Poaceae, Lamiaceae and Fabaceae respectively. Survey results also revealed that most of the recorded species were annuals followed by perennials and biennials. Most abundant species were Bidense pilosa, Chenopodium album, Erigeron canadensis, Cynodon dactylon, Gallinsogo parviflora, Eupatorium adenophorum, Oxalis conrniculata, Parthenium hysterophorus, Lantana camara, Soncchus arvensis, Ageratum conozoides, Plantago major, Ganaphallium lutealbum, Siegesbeckia orientalis, Youngia japonica, Amaranthus virids, Stellaria media and Phalaris minor. Many weeds are ethnobotanically important and utilized by the local community.