Use of Several Natural Products from Selected Nicotiana Species to Prevent Black Shank Disease in Tobacco

Abstract

SUMMARY Black shank is a major annual disease threat to all types of tobacco worldwide. It is caused by the fungus Phytophthora parasitica var. nicotianae (PPN). The major tobacco growing areas in US - Kentucky, Tennessee and North Carolina can experience devastating losses, reaching in some fields up to 100%. Thus far, the main approaches to control this disease have been creation of resistant varieties, fungicide treatments, and crop rotation. Some fungicides are reported to have negative effects on the environment. The goal of this work was to test the antifungal activity of several natural products that are synthesized by certain Nicotiana species, and secreted to the leaf surface. We hypothesized that phylloplanin, cis-abienol, labdenediol and sclareol can suppress PPN-race 0- and PPN-race 1-caused disease in Burley tobaccos KY 14 and MS KY 14 × L8LC in the greenhouse. We developed methods for leaf surface extraction, spore preparation and soil drench application of the natural compounds tested. Experiments were performed on 5–8 week-old greenhouse grown seedlings. cis-Abienol showed high inhibitory properties toward the disease. Race 0 infection was completely subdued in KY 14 while race 1 infection was reduced by 70–80%, and delayed by 6–10 days in KY 14 and MS KY14 × L8LC. Sclareol was very effective in inhibiting race 0-caused disease in both tobacco cultivars. In MS KY 14 × L8LC race 1 infection was inhibited while in KY 14 it was reduced by 85% and delayed by 6 days. Labdenediol reduced the disease by half in eight week-old KY 14 plants. Tobacco phylloplanin reduced plant infection by both races by 50–60% and delayed the disease by 6–10 days. Phylloplanin was least suppressive in both tobacco cultivars. We consider sclareol to be the best candidate for future studies due to its antifungal properties and availability. cis-Abienol, despite its good antifungal activity, is not feasible for large-scale use due to the production and stability limitations.

Terpenoids in the Essential Oil and Concentrated Aromatic Products Obtained from Nicotiana glutinosa L. Leaves

“…We also analyzed the activity of the individual component common to the three aromatic products, sclareol, a substance of importance to the fragrance industry. As stated earlier, sclareol was a characteristic component of N. glutinosa leaf derived aromatic products, and data about its antimicrobial and insecticidal activity have been documented previously [9,11,29,58]. Regrettably, the products showed very limited activity against the test-microorganisms in this study.…”

“…The waxy, musky-sweet-earthy-odored ambergris is highly appreciated and widely used as a fixative in fine perfumery, but its original supply depends on an endangered and protected animal species, sperm whales, and therefore investigations on alternative supply routes are relevant. Beside its perfume-fixating value, sclareol is also identified with a number of beneficial activities, such as antifungal, antimicrobial, growth-regulating, anti-inflammatory, and others [9,11,29,58]. Therefore, the results about the high content of sclareol in the two concentrated aromatic products of N. glutinosa, and in particular in the concrete, may be considered very promising in terms of potential future use and larger-scale production.…”

Unraveling the expression of differentially expressed proteins and enzymatic activity in response to Phytophthora nicotianae across different flue-cured tobacco cultivars

“…The infected plants generally show symptoms of root and crown rot, yellowing, wilting, and necrosis of leaves. On cut stems, the signs of P. nicotianae are observed as white mycelium on the necrotic plate-like disks [ 7 ]. The average disease incidence of tobacco black shank is recorded between 10 to 20%, but it can reach up to 100% [ 8 ].…”

Study on the Migration of Phytophthora nicotianae Zoospores in the Soil

“…nicotianae, is a soil-borne biflagellated oomycete plant pathogen, which causes black shank in cultivated tobacco (Nicotiana tabacum Solanaceae) by infecting tobacco roots, stems and leaves at any stage of plant growth (Deacon and Donaldson, 1993;Antonopoulos et al, 2010;Ping and Hong, 2014). P. nicotianae is a devastating disease for tobacco, and it is widely distributed in various tobacco cultivation zones all over the world (Kroumova et al, 2016). Previous studies have shown that in North Carolina annual output losses of the fluecured tobacco ranged from 1 to 3% because of P. nicotianae, which resulted in millions of dollars (Antonopoulos et al, 2010), and in China more than 76373 hm 2 of the flue cured tobacco are damaged every year (Chen et al, 1997;Li et al, 2011).…”

“…At present, studies on zoospores mainly focus on their infection, pathogenesis regularities, and the cultivation and identification of disease-resistant plant species (Chuan et al, 2016;Hui et al, 2016;Kroumova et al, 2016). Previous studies have thus far investigated the effects of water, pH, CO2, EC and dissolved O2 concentration on zoospore survival (Kong et al, 2012;Kong, 2013;Ahmed et al, 2016).…”