Role Of Elicitors Research Articles

Plant Bioactive Compounds: Crucial Pharmacological Properties and Role of Elicitors in Enhancing Production

Plant Bioactive Compounds: Crucial Pharmacological Properties and Role of Elicitors in Enhancing Production

Impact of elicitors on essential oil compositions and phytochemical constituents in Lavandula stoechas L.

Lavandula stoechas L. (LS) is an aromatic evergreen herb used broadly in the food, pharmaceutical, and perfume industries. However, the inducer effect of elicitors on secondary metabolites (SMs) biosynthesis in LS is nebulous. In addition, the precise mechanism of elicitors in cells remains unexplored. Hence, the primary objective of this study was to analyze the changes in phytochemical compositions of LSs treated with a biotic elicitor (chitin) and an abiotic one (copper nanoparticle) under in vitro and greenhouse conditions, with the aim of choosing an appropriate elicitor type, concentration, and exposure time for this species. In this study, the biochemical function of four chitin concentrations (i.e. 0, 50, 100 & 200 mg L−1) and four copper oxide nanoparticle concentrations (i.e. 0, 25, 50, & 100 mg L−1) at two exposure times (i.e. 5 & 10 days) was investigated in LS so as to compare with the un-elicited explants and the original plant materials. The analysis showed that the highest contents of the total phenolic (4.68 mg g−1 FW), flavonoids (0.68 mg g−1 FW), anthocyanins (36.51 mg g−1 FW), and flavonols (0.29 mg g−1 FW) compounds were observed in the elicited LSs. Besides, the role of elicitors in augmenting the percentage of SMs was intelligible, especially ‘lavandulol’, ‘1,8-cineole’, ‘germacrene D’, and ‘(E)-nerolidol’, which increased by 21.68%, 17.21%, 9.33%, and 8.11%, respectively. In conclusion, these findings indicate that utilizing elicitors at optimal concentrations and with timely durations of exposure can largely assist in improving the biotechnological production of SMs in LS, so that their potential for industrial use can be actualized.

The carbohydrate elicitor Riclinoctaose facilitates defense and growth of potato roots by inducing changes in transcriptional and metabolic profiles

Promoting both root growth and defense is conducive to the production of potatoes (Solanum tuberosum L.), while the role of elicitors in this topic hasn’t been fully understood. To investigate the effect of Riclinoctaose (RiOc) on root growth and defense, potato tissue cuttings were cultivated with different concentration of RiOc (0, 50, 200 mg/L) for 5 weeks and changes in root morphology, transcription, enzymatic and metabolomic profiles were monitored over time. The results indicated that RiOc triggered the salicylic acid (SA)-mediated defense response and facilitated the growth of adventitious and lateral roots in a dose- and time-dependent manner. MPK3/MPK6, SA- and auxin-signaling pathways and transcription factors such as WUS, SCR and GRAS4/GRAS9 participated in this process. Moreover, the 1H NMR based metabolome profiling demonstrated that potato roots altered the primary metabolism to respond to the RiOc elicitation and efficiency in production and allocation of defense and growth-related metabolites was improved. After 5-week treatment, the level of glucose, N-acetylglucosamine, glutamine, asparagine, isoleucine, valine, 3-hydroxyisovalerate and ferulate increased, while acetate, acetoacetate, fucose, and 2-hydroxyphenylacetate declined. In conclusion, RiOc played dual roles in activating the SA-mediated defense response and in promoting growth of potato roots by inducing changes in root transcription and metabolism.

Role of Elicitors in Chlorophyll Content and Stomatal Density of Soybean Cultivars by Foliar Application

Role of Elicitors in Chlorophyll Content and Stomatal Density of Soybean Cultivars by Foliar Application

Postharvest quality of tuberose (Polianthes tuberosa) loose flower as affected by elecitor treatment

Tuberose (Polianthes tuberosa L.)is one of the most important commercial loose and cut flower crops grown in India and other countries. Its florets (loose flowers) retain their freshness only for a few days under ordinary condition. The objective of the present study was to investigate role of elicitors on shelf life and physiological traits in florets of tuberose cultivars Mexican Single, Prajwal and Sikkim Selection. There were ten treatments i.e., three elicitors (boric acid, salicylic acid and nitric acid) and their three concentrations (50, 100 and 200 ppm each) and a control (distilled water), replicated thrice in completely randomized design. The statistically analysed data revealed that in cvs. Mexican Single, Prajwal and Sikkim Selection the greater floret diameter retention (4.64, 5.00 and 5.39 mm, respectively), floret weight retention (0.65, 0.70 and 0.89g, respectively), relative water content (84.03, 81.97 and 88.86%, respectively) and membrane stability index (76.90, 77.32 and 79.81%, respectively) were obtained with treating of florets in 200 ppm boric acid solution. Significantly lower for above mentioned parameters were recorded under control treatment. Higher freshness index (5 for all 3 cultivars) and shelf life (5.1, 6.0 and 5.0 day, respectively) of florets were expressed with treatment of 200 ppm each of boric acid, salicylic acid and nitric acid solution and the lower values under control treatment. Total sample weight and physiological loss in weight of florets did not differ significantly by application of different treatments.

The Ties of Meeting Leaders: A Social Network Analysis

This study extends meeting research by applying social network analysis to meeting leaders’ behavior in actual, videotaped meetings (N = 46) and examining the position of meeting leaders in the meeting network. Analyses reveal that meeting leaders are key players in meetings taking on the roles of central actor, broker, and elicitor. The role of central actor is linked to the number of planned actions during the meeting whereas the role of elicitor is associated with participants’ satisfaction with the meeting leader and team productivity after the meeting. Our study highlights the different roles meeting leaders need to juggle to run meetings effectively.

Role of Elicitors in Inducing Resistance in Plants against Pathogen Infection: A Review.

Disease control is largely based on the use of fungicides, bactericides, and insecticides—chemical compounds toxic to plant invaders, causative agents, or vectors of plant diseases. However, the hazardous effect of these chemicals or their degradation products on the environment and human health strongly necessitates the search for new, harmless means of disease control. There must be some natural phenomenon of induced resistance to protect plants from disease. Elicitors are compounds, which activate chemical defense in plants. Various biosynthetic pathways are activated in treated plants depending on the compound used. Commonly tested chemical elicitors are salicylic acid, methyl salicylate, benzothiadiazole, benzoic acid, chitosan, and so forth which affect production of phenolic compounds and activation of various defense-related enzymes in plants. Their introduction into agricultural practice could minimize the scope of chemical control, thus contributing to the development of sustainable agriculture. This paper chiefly highlights the uses of elicitors aiming to draw sufficient attention of researchers to the frontier research needed in this context.

Bringing Sexuality to the Table

In their 1995 study, “The ‘Father Knows Best’ Dynamic in Dinnertime Narratives,” Ochs and Taylor observed patterns of male dominance in conversations between heterosexual parents of nuclear families. The playing out of these imbalanced gender roles, the researchers cautioned, has a socializing effect that can be seen in the behavior of their young children. The paper presented here reexamines these power dynamics through an analysis of the discourse between lesbian parents with children. The author examines the linguistic tools used in the negotiation of power, both in comparison to Ochs and Taylor’s findings and for their own unique characteristics. This analysis reveals that in these seven families, like those in Ochs and Taylor’s research, one parent evaluates others’ speech and actions considerably more often than the other. However, the parents did not occupy the other roles examined in the original study in the same way. In particular, the role of primary recipient seems to be less powerful here than in the original study, while the role of elicitor appears to allow women a more effective means by which to attain and maintain control. A high incidence of joint elicitation and narration by the parents, and an active attempt to include children in the conversations were also found. These findings point to two conclusions: (1) the use of evaluative comments is not necessarily a gendered power tactic; (2) a high level of conscious decision making by lesbian parents seems to explain some of these differences in form. Future research should examine the influence of power rather than gender differences in speech acts. In so doing, we might more fully understand the nature of powerful language and which speech groups have access to that means of discourse.

Defesas químicas de plantas: fitoalexinas

A resistência de plantas ao ataque de microorganismos causadores de doenças relaciona-se à presença de barreiras físicas e (juímicas de defesa. Dentre as barreiras químicas destacam-se as fitoalexinas, substâncias fungitoxicas sintetizadas de novo pelas plantas principalmente após a invasão ou o contato de seus tecidos com microorganismos, Essas substâncias englobam vários grupos compostos naturais tais como terpenos, isoflavonóides e poliacetilenos e seu acúmulo pode ser induzido por organismos vivos, seus produtos (elíciadores) ou ainda agentes químicos, como sais de metais pesados, ou físicos (congelamento, luz U.U.). Alguns aspectos abordados nesta revisão são: a ocorrência de fitoalexinas em angiospermas, a relação entre sua natureza química e o grupo taxonômico das plantas que as produzem, a sua ação sobre organismos pró e eucarióticos. São descritas também os fatores que interferem nas respostas das plantas aos agentes indutores e as técnicas usuais para a indução e detecção de fitoalexinas. O papel dos eliciadores na indução da sâitese de fitoalexinas e o mecanismo pelo qual exercem sua função indutora são discutidos. Nesse contexto está incluída a teoria das oligossacarinas, fragmentos de parede celular que parecem controlar não só a resposta de defesa em plantas mas também outros fenômenos fisiológicos em plantas.

Alternativen beim Pflanzenschutz?

The control of plant diseases may be improved by influencing the development of a parasite in its host. The role of elicitors and inducers for the induction of the plant's defense reactions and the use of hyperparasites is discussed as a part of an integrated pest management system of rust fungi.

Host-Pathogen Interactions

The structures of the four wall-released elicitor fractions isolated from the Phytophthora megasperma var. sojae mycelial walls have been examined. The results demonstrate that fraction I is primarily composed of a branched beta-1,3-glucan, similar in structure to the extracellular elicitors described previously (Ayers, A., J. Ebel, F. Finelli, N. Burger, and P. Albersheim. 1976. Plant Physiol. 57: 751-759). Fractions II and IV are primarily composed of a highly branched mannan-containing glycoprotein, with fraction IV richer in protein than fraction II. Fraction III contains, attached to protein, a mixture of the two polysaccharide types found in fraction I and in fractions II and IV. The structural data presented here, in concert with the biological data presented in the previous two papers (Ayers et al. 1976. Plant Physiol. 57: 751-759; 760-765), demonstrate that the only compound produced by P. megasperma var. sojae which contains elicitor activity is the glucan. Evidence is presented that the terminal glycosyl residues of the glucan are required for elicitor activity. In addition, it is demonstrated that 90% of the glucan can be removed enzymically without any loss of biological activity. The active residue of the enzymic digestion is a highly branched 3- and 3,6-linked glucan containing about 4% mannosyl residues. The results presented suggest that the mannosyl residues of the glucan, which represent only about 1% of the undegraded glucan, are likely to participate in the active site of this molecule. The role of elicitors and phytoalexins in host-pathogen interactions is discussed. Evidence for the existence of and possible identity of another factor, which determines race specificity of host-pathogen interactions, is summarized.