PHYSIOLOGICAL ONTOGENY IN THE TOBACCO PLANT

1940 ◽  
Vol 18 (1) ◽  
pp. 21-34 ◽  
Author(s):  
E Dorothy Ward ◽  
AHK Petrie
Keyword(s):  
Tobacco Plant

scholarly journals Effect of the native strain of the predator Nesidiocoris tenuis Reuter and the entomopathogenic fungi Beauveria bassiana and Lecanicillium muscarium against Bemisia tabaci (Genn.) under greenhouse conditions in Tunisia

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Besma Hamrouni Assadi ◽  
Sabrine Chouikhi ◽  
Refki Ettaib ◽  
Naima Boughalleb M’hamdi ◽  
Mohamed Sadok Belkadhi
Keyword(s):  
Beauveria Bassiana ◽  
Bemisia Tabaci ◽  
Entomopathogenic Fungi ◽  
Tobacco Plant ◽  
Economic Losses ◽  
Native Strain ◽  
Lecanicillium Muscarium ◽  
Southern Tunisia ◽  
Significant Efficacy ◽  
Nesidiocoris Tenuis

Abstract Background The misuse of chemical insecticides has developed the phenomenon of habituation in the whitefly Bemisia tabaci (Gennadius) causing enormous economic losses under geothermal greenhouses in southern Tunisia. Results In order to develop means of biological control appropriate to the conditions of southern Tunisia, the efficacy of the native strain of the predator Nesidiocoris tenuis Reuter (Hemiptera: Miridae) and two entomopathogenic fungi (EPF) Beauveria bassiana and Lecanicillium muscarium was tested against Bemisia tabaci (Gennadius). Indeed, the introduction of N. tenuis in doses of 1, 2, 3, or 4 nymphs per tobacco plant infested by the whitefly led to highly significant reduction in the population of B. tabaci, than the control devoid of predator. The efficacy of N. tenuis was very high against nymphs and adults of B. tabaci at all doses per plant with a rate of 98%. Likewise, B. bassiana and L. muscarium, compared to an untreated control, showed a very significant efficacy against larvae and adults of B. tabaci. In addition, the number of live nymphs of N. tenuis treated directly or introduced on nymphs of B. tabaci treated with the EPF remained relatively high, exceeding 24.8 nymphs per cage compared to the control (28.6). Conclusions It can be concluded that the native strain of N. tenuis and the EPF tested separately were effective against B. tabaci. Their combined use appears to be possible.

Elicitins' Oligomeric States Affect The Hypersensitive Response And Resistance In Tobacco

2021 ◽  
Author(s):  
Martin Solanský ◽  
Kamil Mikulášek ◽  
Martina Zapletalová ◽  
Marek Petřivalský ◽  
Annick Chiltz ◽  
...  
Keyword(s):  
Hypersensitive Response ◽  
Early Recognition ◽  
Tobacco Plant ◽  
Plant Defence ◽  
Microbial Pathogens ◽  
Plant Responses ◽  
Resistance Response ◽  
Basal Resistance ◽  
Pathogenesis Related Protein ◽  
Fast Activation

Abstract Successful plant defence against microbial pathogens is based on early recognition and fast activation of inducible responses. Key mechanisms include detection of microbe-associated molecular patterns by membrane-localized Pattern Recognition Receptors that induce a basal resistance response. A well-described model of such responses to pathogens involves interaction between Solanaceae plants with proteinaceous elicitors secreted by oomycetes, called elicitins. It has been hypothesised that elicitins' formation of oligomeric structures could be involved in their recognition and activation of defensive transduction cascades. In tests of this hypothesis reported here, using several approaches, we observed differences in tobacco plant responses induced by the elicitin β-cryptogein (β-CRY) and its homodimer (β-CRY DIM). We also found that the C-terminal domain of elicitins of other ELI clades plays a significant role in stabilization of their oligomeric structure and restraint in the cell wall. In addition, covalently crosslinking β-CRY DIM impaired formation of signalling complexes, thereby reducing its capacity to elicit the hypersensitive response and resistance in the host plant, with no significant changes in pathogenesis-related protein expression. The results illuminate the poorly understood role of elicitins' oligomeric structures in oomycetes' interaction with plants, by revealing details of effects of β-CRY dimerization on tobacco plants' recognition and defence responses.

Bio‐oil from Tobacco Plant

2022 ◽  
pp. 397-420
Author(s):  
Andre F.P. Harahap ◽  
Ahmad Fauzantoro ◽  
Misri Gozan
Keyword(s):  
Tobacco Plant ◽  
Bio Oil

Tobacco rosette: a complex virus disease

Parasitology ◽  
1946 ◽  
Vol 37 (1-2) ◽  
pp. 21-24 ◽  
Author(s):  
Kenneth M. Smith
Keyword(s):  
Myzus Persicae ◽  
Complex Disease ◽  
Virus Disease ◽  
Tobacco Plant ◽  
Giant Cells ◽  
Mottle Virus ◽  
Insect Vector ◽  
Two Component ◽  
Set Up ◽  
Abnormal Tissue

An account is given of a composite virus disease of tobacco for which the name tobacco rosette has been suggested.The two component viruses, named the mottle and vein-distorting viruses respectively, have been separated, and their symptomatology and methods of transmission described. The mottle virus is both sap and aphis-transmitted, but the vein-distorting virus is aphis-borne only.The symptoms and histopathology of the complex disease in the tobacco plant are dealt with in some detail. There are three main types of symptoms: (1) intense rosetting, (2) splitting of the tissues, (3) formation of enations on the under-surface of the leaves.The splitting of the tissues has been examined microscopically, and a number of photomicrographs are given illustrating the formation of the fissures. It is suggested that there is a concentration of virus in the cambium which prevents the formation of the normal xylem. Abnormal tissue and giant cells are formed in the cortex and pith. This appears to set up stresses which cause the splitting.The insect vector of the complex disease is the aphis Myzus persicae Sulz. Another aphis, M. pseudosolani Theob., is also a vector but is less efficient than M. persicae.The writer's thanks are due to Prof. F. T. Brooks, F.R.S., with whom he discussed the histopathology of the rosette disease, to Dr Roy Markham for taking the photographs illustrating Pl. I, figs. 2–5, and to Mr Charles Harpley of the Molteno Institute for his assistance in taking' the photomicrographs.

scholarly journals Characterization of a Drought-Inducible Dehydrin Promoter from Sugarcane (Saccharum officinarum L.) in Tobacco (Nicotiana tabacum L.)

2020 ◽  
Vol 7 (01) ◽  
pp. 28-36
Author(s):  
Hayati Minarsih Iskandar ◽  
Sonny Suhandono ◽  
Jembar Pambudi ◽  
Tati Kristianti ◽  
Riza Arief Putranto ◽  
...  
Keyword(s):  
Drought Stress ◽  
Tobacco Plant ◽  
Inducible Promoter ◽  
Saccharum Officinarum ◽  
Blue Color ◽  
Drought Treatment ◽  
Stress Treatment ◽  
Gus Reporter ◽  
Transformed Tobacco

Dehydrin (DHN) is known to play an important role in plant response and adaptation to abiotic stresses (drought, high salinity, cold, heat, etc.). Previous research reported the increased expression of DHN in sugarcane stems exposed to drought stress for 15 days which may be controlled by its corresponding stress inducible promoter. The DHN promoter was succesfully isolated from sugarcane variety PSJT 941 (Pr-1DHNSo) and was cloned to pBI121 expression vector fused to a β-glucuronidase (GUS) reporter gene.  The aim of this research was the functional testing of the Pr-1DHNSo promoter through transformation into tobacco plant treated with in vitro drought stress. Genetic transformation of Pr-1DHNSo construct was conducted by Agrobacterium tumefaciens. The transformed tobacco was then subjected to drought stress treatment using 40% PEG 6000  for five sequential incubations (0, 12, 24, 48 and 72 hours). The GUS assay reveal that the transformed tobacco treated with drought stress showed a blue color denoting GUS activity in leaf, stem and root tissues and this expression increased along with the length of the drought treatment. The analysis of gusA gene using real time-qPCR normalized to the L25 reference gene also showed that the expression increased in line with the length of time of drought stress.  The results presented in this study indicated that the Pr-1DHNSo promoter from sugarcane was expressed and induced by drought stress treatment in tobacco.

scholarly journals PEMANFAATAN EKSTRAK DAUN TEMBAKAU (Nicotiana tabacum L) UNTUK MENGENDALIKAN ULAT GRAYAK (Spodoptera litura F) PADA TANAMAN SAWI (Brassica juncea L.) DI LAPANG

AGRICA ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 1-8
Author(s):  
Maria Goreti Firma
Keyword(s):  
Spodoptera Litura ◽  
Leaf Extract ◽  
Tobacco Plant ◽  
Block Design ◽  
Fresh Weight ◽  
Leaf Extracts ◽  
Tobacco Leaf ◽  
Randomized Block Design ◽  
Nicotiana Tabacum L ◽  
Mustard Plant

This study aims to determine the effect of tobacco plant extracts on mortality of armyworm pests (Spodoptera litura F.) and determine the optimum concentration of tobacco leaf extracts on mortality of armyworm caterpillars on mustard plants in the field. The design used in this study was a Randomized Block Design (RBD) consisting of 5 treatments and 4 replications namely T1: 175 ml/L concentration of tobacco leaf extract, T2: 350 ml/L concentration of tobacco leaf extract T3: Concentration of 525 ml/L tobacco leaf extract, T4: Concentration of 700 ml/L tobacco leaf extract, T5: Concentration of 875 ml/L of tobacco leaf extract. The observation variables in this study were pest mortality (%), damage intensity (%), plant fresh weight, and fresh weight per hectare (ton). The results showed that the concentration of tobacco leaf extracts significantly affected the mortality of Spodoptera litura F. At the concentration of T5 treatment (875 ml) were the lowest damage, pest mortality, fresh weight of the mustard plant, and fresh weight per hectare of was 9.75%, 88%, 109.25 gr, and27.31 tons respectively.

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