We sprayed defence-related plant growth regulators (salicylic acid, methyl jasmonate and ethephon) on one-month-old Habanero pepper seedlings cultivated in vitro. Twenty-four hours later, we inoculated the seedlings with a virulent strain of Phytophthora capsici and periodically evaluated the disease symptoms. At the concentrations used, neither salicylic acid nor methyl jasmonate generated a protective effect in the seedlings, which died less than 10 days post inoculation. However, the treatment with 5 mM ethephon delayed or prevented disease symptoms in 30% of the seedlings. Interestingly, blocking the ethylene receptor with a previous application of 300 μM silver nitrate impeded the protective effects of ethephon. This result demonstrated that the plant resistance response required the perception of ethylene. Analysis of transcript populations in ethephon-treated seedlings revealed a direct correlation between survival and the accumulation of PR1, a gene marker of the systemic acquired resistance (SAR). Although the ethephon treatment also modified transcript levels of the plant defensin PDF1.2, a marker of the induced systemic resistance (ISR), in this case the accumulation also occurred when the ethylene receptor was blocked, suggesting a non-specific effect. The ethephon treatment did not modify the expression of NPR1 (a key transcriptional regulator of plant defence). Interestingly, transgenic pepper seedlings overexpressing endogenous PR10 or esterase genes, which are induced by the ET treatment, completely resisted the infection, which corroborated the importance of these genes in the defence response. Our results suggest that ethylene induced a systemic defence response in susceptible seedlings, possibly in an NPR1-independent pathway.
This study's aim was to establish a protocol for the micropropagation of G. skinneri using temporary immersion system (TIS). Different concentrations of 6-Benzylaminopurine (0, 1, 2, and 3 mg L −1 ), three different systems of cultivate semi-solid (SS) and liquid media under partial (PI) and temporary immersion systems (TIS), different compositions of the inorganic salts, and the number of subcultures were evaluated. The results showed a maximum of 16.56 shoots per explant obtained through TIS, adjusting all the parameters evaluated in our study. One higher number of shoots per explant was observed in the micropropagation of G. skinneri TIS compared to SS and PI. While the use of 3 mg L −1 of BAP + MS (Murashige and Skoog) media was better than 3 mg L −1 of BAP VW (Vacint and Went) for the generation of a greater number of shoots per explant, 6.33 and 2.72, respectively. The immersion frequency of 2 min every 4 h allowed the production to be scaled to 8.54 shoots per explant. While it was necessary to perform three subcultures every 30 days, to obtain 16.56 shoots per explant, a rooting phase was not required due to the generation of adventitious roots during the different subcultures. However, a phase of elongation of the regenerated plants with ½ MS + GA3 (gibberellic acid) was needed to guarantee 100% survival in the process of acclimatization. In conclusion, this plant production system can be applied for the commercial micropropagation of this species for ornamental purposes, as well as for its reintroduction in protected natural areas.
El chile Manzano o Cera (Capsicum pubescens), es una planta perenne originaria de las tierras altas de América del Sur. Durante su almacenamiento, el principal problema que presenta es su testa, lo cual ocasiona una disminución de la germinación en condiciones naturales. Debido a que existe poca información sobre la germinación, es necesario implementar alternativas que garanticen el recurso dentro de un programa de mejoramiento genético. El objetivo fue evaluar el efecto de ácido sulfúrico (H2SO4), peróxido de hidrógeno (H2O2) y ácido giberélico-3 (C19H22O6) sobre el porcentaje de emergencia y características de plántulas de semillas de C. pubescens. El experimento se realizó en la Unidad de Manejo y Conservación de Recursos Genéticos de la Facultad de Ciencias Biológicas y Agropecuarias de la Universidad Veracruzana. Se utilizaron semillas de C. pubescens provenientes de la localidad de Huatusco, Veracruz, México, almacenadas a temperatura ambiente durante un año. Los tratamientos estudiados fueron: inmersión en H2SO4 (100, 75, 60 %; 30 min); inmersión en H2O2 (20, 10, 15 %; 15 min), inmersión en C19H22O6 (25, 20, 15 mg; 24 h) y el tratamiento testigo. Los resultados en el presente estudio revelan diferencias estadísticas significativas (P ≤ 0,01) para todas las variables evaluadas. El mejor porcentaje de germinación se provocó con inmersión en C19H22O6 (15 mg; 24 h) y H2O2 (20 %; 15 min). El tratamiento con H2SO4 fue perjudicial ya que no hubo emergencia.
We analysed changes in the transcript population produced in habanero pepper (Capsicum chinense) cell suspensions by the addition of whole mycelium homogenates from a pathogenic isolate of Phytophthora capsici, to identify plant cellular processes modified by the oomycete effectors. The elicitation produced several defence-like cellular responses: alkalinisation of the medium, a two-step oxidative burst, induction of β-1,3-glucanases, and activation of mitogen-activated protein kinases. The elicitation modified the accumulation of transcripts representative of diverse metabolic pathways, including ethylene biosynthetic enzymes, MAP kinases and defence-related products, like PR proteins, but did not affect the expression of C. chinense NPR1 and WRKY orthologue genes, which are important modulators of plant defence responses. Interestingly, apart from some defence-related genes, inoculation of sixleaf-stage habanero pepper plantlets with the pathogenic isolate revealed few systemic modifications in the transcript patterns. All plantlets ultimately died, even though the in planta inoculation induced the strong accumulation of two MAPK transcripts. As few resistance-related genes were expressed in susceptible habanero pepper plantlets that died, either the extent or the timing of the defence response could be insufficient to establish a proper response against Phytophthora blight.
The APETALA2/Ethylene response factor (AP2/ERF) family of transcription factors (TFs) plays crucial roles in the regulation of gene expression during plant development and in response to biotic and abiotic stress. Although AP2/ERFs have been implicated in a range of plant stress responses, this review focuses on ERFs in the context of the plant response to other organisms, primarily not only pathogenic but also symbiotic. The ERF subfamily is particularly important in the establishment and the tight regulation of plant defences through a balance of positive and negative transcriptional regulation. The expression of the ERFs is induced by pathogens with different lifestyles and they have been implicated in resistance to biotrophs, necrotrophs and hemibiotrophs, but members also play important roles in other plant-microbe interactions, for example, nodule formation in legumes. ERFs achieve this, in part, by acting as integrators in the crosstalk between signalling pathways mediated by ethylene (ET), jasmonic acid, salicylic acid and other plant hormones to modulate gene expression according to the stimuli sensed. This review collates recent findings on the regulation of this family of TFs, including transcriptional and post-translational regulation. Although DNA binding is typically conferred through the characteristic AP2 domain, the function of other domains including the EDLL and ERF-associated amphiphilic repression (EAR) domains in regulating gene expression is discussed. Finally, the potential for ERFs to be used to enhance resistance to pathogens in crops is considered.
Taro is important for its nutritional content, medicinal use, and bioethanol production. The aim of the present study was to compare different semi-automated bioreactors (SABs) during in vitro multiplication of C. esculenta. The SABs used were temporary immersion bioreactors (TIBs), SETIS™ bioreactors and ebb-and-flow bioreactors; semi-solid culture medium was used as a control treatment. At 30 d of culture, different developmental variables, determination of chlorophyll, stomatal content, and survival percentage during acclimatization were evaluated. SABs increased the shoot multiplication rate relative to the semi-solid medium; however, the SETIS™ bioreactor showed the highest shoot production, with 36 shoots per explant, and the highest chlorophyll content. The stomatal index was higher in the semi-solid medium compared to the SABs, while the percentage of closed stomata was higher in the SABs than in the semi-solid culture medium. The survival rate during acclimatization showed no differences among the culture systems assessed, obtaining survival rates higher than 99%. In conclusion, the SETIS™ bioreactor showed the highest multiplication rate; however, other bioreactor alternatives are available for semi-automation and cost reduction for micropropagation of C. esculenta.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.