Application Of Benzothiadiazole Research Articles

Induction of Systemic Resistance of Benzothiadiazole and Humic Acid in Soybean Plants Against Fusarium Wilt Disease

The ability of benzothiadiazole (BTH) and/or humic acid (HA) used as seed soaking to induce systemic resistance against a pathogenic strain of Fusarium oxysporum was examined in four soybean cultivars under greenhouse conditions. Alone and in combination the inducers were able to protect soybean plants against damping-off and wilt diseases compared with check treatment. These results were confirmed under field conditions in two different locations (Minia and New Valley governorates). The tested treatments significantly reduced damping-off and wilt diseases and increased growth parameters, except the number of branches per plant and also increased seed yield. Application of BTH (0.25 g/L) + HA (4 g/L) was the most potent in this respect. Soybean seed soaking in BTH + HA produced the highest activities of the testes of oxidative enzymes followed by BTH in the four soybean cultivars. HA treatment resulted in the lowest increases of these oxidative enzymes. Similar results were obtained with total phenol but HA increased total phenol more than did BTH in all tested cultivars.

Induction of systemic resistance in soybean plants against Fusarium wilt disease by seed treatment with benzothiadiazole and humic acid

The ability of benzothiadiazole (BTH), humic acid (HA) and their combination when used in seed soaking to induce systemic resistance against a pathogenic strain of Fusarium oxysporum was examined in four soybean cultivars under greenhouse conditions. Both inducers and their combination were able to protect soybean plants against damping-off and wilt diseases compared with check treatment. These results were confirmed under field conditions in two different locations that is, Minia and New Valley governorates, Egypt. The tested treatments significantly reduced damping-off and wilt diseases and increased growth parameters, except number of branches plant-1, and seed yield. Application of BTH (0.25) + HA (4 g/L) was the most potent in respect to this treatment. Soybean seed soaking in BTH+HA recorded the highest activities of oxidative enzymes followed by BTH in four soybean cultivars. Whereas, HA treatment recorded the lowest increase of these oxidative enzymes. Also, similar results were obtained in case of total phenol but HA increased the total phenol more than BTH in all tested cultivars. Key words: Induce systemic resistance, soybean, wilt disease, benzothiadiazole (BTH), humic acid (HA).

Quantitative comparison of chemical, biological and mechanical induction of secondary compounds in Pinus pinaster seedlings

Chemical elicitors and mechanical treatments simulating real insect herbivory have been increasingly used to study induced defensive responses in woody plants. However, simultaneous quantitative comparisons of plant chemical defences elicited by real and simulated herbivory have received little attention. In this paper we compared the effects of real herbivory, simulated herbivory using two chemical elicitors, and mechanical damage treatments on the quantitative secondary chemistry of Pinus pinaster juveniles (namely on non-volatile resin in the stem and total phenolics in the needles). The real herbivory involved phloem wounding by Hylobius abietis and defoliation by Brachyderes lusitanicus (two pine weevils); the chemical elicitors to simulate herbivory induction were 40 mM methyl jasmonate (MJ) and 20 μM benzothiadiazole (BTH); and the mechanical treatments included phloem wounding and needle clipping. We also performed an additional experiment for assessing at what extent insect extracts could increase plant responses over mechanical damage. Chemical induction with MJ, mechanical wounding and real phloem herbivory by H. abietis all produced quantitatively similar results, increasing the concentration of resin in the stem and total phenolics in the needles by equivalent magnitudes. Exogenous application of BTH increased the concentration of phenolic compounds in pine needles, but did not show the same effect on stem resin. Contrastingly, we did not find significant changes in the concentration of resin in the stem or phenolics in the needles after needle clipping and B. lusitanicus feeding. Mechanical damage followed by the application of extracts from the insects B. lusitanicus and H. abietis on the injured tissues did not increase the responses in comparison to mechanical damage alone. The fact that strong induced responses elicited by phloem wounding insects are equally elicited by phloem injuries suggests that defences in pine trees are raised with low specificity regarding biotic enemies. Results from this paper support future methodological approaches using chemical elicitors and mechanical damage as simulated herbivory treatments for the experimental induction of conifer defences.

Induction of Systematic Resistance in Soybean Plants against Fusarium Wilt Disease by Seed Treatment with Benzothiadiazole and Humic Acid

The ability of benzothiadiazole (BTH), humic acid (HA) and their combination when used as seed soaking to induce systemic resistance against a pathogenic strain of Fusarium oxysporum was examined in four soybean cultivars under greenhouse conditions. Both inducers and their combination were able to protect soybean plants against damping-off and wilt diseases compared with check treatment. These results were confirmed under field conditions in two different locations i. e Minia and New Valley governorates. The tested treatments significantly reduced damping-off and wilt diseases and increased growth parameters, except number of branches plant-1, and seed yield. Application of BTH (0.25) + HA (4 g/l) was the most potent in this respect treatment. Soybean seed soaking in BTH+ HA recorded the highest activities of the testes of oxidative enzymes followed by BTH in the four soybean cultivars. Whereas, HA treatment was recorded the lowest increased of these oxidative enzymes. Also, similar results were obtained in case of total phenol but HA increased the total phenol more than BTH in all tested cultivars.

Comparison of induced resistance activated by benzothiadiazole, (2R,3R)‐butanediol and an isoparaffin mixture against anthracnose of Nicotiana benthamiana

Resistance in Nicotiana benthamiana against anthracnose caused by the hemibiotrophic fungus Colletotrichum orbiculare was activated by benzothiadiazole (BTH), (2R,3R)­butanediol or PC1, an isoparaffin‐based mixture. In inoculation experiments, BTH, (2R,3R)­butanediol and PC1 reduced the number of lesions per leaf area caused by C. orbiculare by 98%, 77% and 81%, respectively. Foliar application of BTH induced expression of genes for the acidic pathogenesis‐related (PR) proteins, NbPR‐1a, NbPR‐3Q and acidic NbPR‐5. In contrast, soil application of (2R,3R)­butanediol or PC1 primed expression of genes for the basic PR proteins, NbPRb‐1b, basic NbPR‐2 and NbPR‐5dB. These results are consistent with the activation of salicylic‐acid‐dependent systemic acquired resistance (SAR) by BTH and that of jasmonate/ethylene‐dependent induced systemic resistance (ISR) by (2R,3R)­butanediol or PC1, and show that (2R,3R)­butanediol and PC1 can affect gene expression similarly to plant growth‐promoting rhizobacteria. However, the effects of (2R,3R)‐butanediol and PC1 were not identical. In addition to priming, (2R,3R)‐butanediol induced expression of basic NbPR‐2, whereas PC1 treatment induced expression of both NbPRb‐1b and basic NbPR‐2. Although a number of microbial products, such as (2R,3R)­butanediol, have been shown to produce ISR, this is the first demonstration that an isoparaffin‐based mixture, not derived from a microorganism, can produce ISR.

Enhanced Onion Resistance against Stemphylium Leaf Blight Disease, Caused by Stemphylium vesicarium, by Di-potassium Phosphate and Benzothiadiazole Treatments

In this study, we investigated the induced defense response and protective effects against Stemphylium vesicarium by application of benzothiadiazole (<TEX>$Bion^{(R)}$</TEX>) and di-potassium phosphate salt <TEX>$(K_2HPO_4)$</TEX> to onion. Onion leaves were sprayed with <TEX>$Bion^{(R)}$</TEX> and <TEX>$K_2HPO_4$</TEX>, then inoculated 2 days later with a virulent strain of S. vesicarium under greenhouse conditions. Disease severity and activities of peroxidase (PO), polyphenoloxidase, phenylalanine ammonia-lyase (PAL) and phenol contents were evaluated in the treated leaf tissues. Reduction in the disease severity was observed in plants treated with <TEX>$Bion^{(R)}$</TEX> and <TEX>$K_2HPO_4$</TEX>. Onion plants treated with <TEX>$Bion^{(R)}$</TEX> and <TEX>$K_2HPO_4$</TEX> and inoculated with the pathogen showed significantly higher PAL activity, PO activity, and phenol contents than inoculated water-treated plants 2 days after the treatment. In conclusion, the results of this study provide evidence that application of simple non-toxic chemical solutions as di-potassium phosphate and <TEX>$Bion^{(R)}$</TEX> can control Stemphylium leaf blight of onion.

Pre-harvest application of 2, 6-dichloroisonicotinic acid, -aminobutyric acid or benzothiadiazole to control post-harvest storage diseases of melons by inducing systemic acquired resistance (SAR)

SummaryField-grown rockmelon plants were treated with -aminobutyric acid (BABA), 2,6-dichloroisonicotinic acid (INA), benzothiadiazole (BTH) or water during fruit development and evaluated for increased resistance against plant diseases or post-harvest pathogens. One experiment was conducted at Camden, NSW, Australia (INA, BABA or water). Two experiments were at Griffith, NSW, Australia (INA, BTH or water). Growing plants and harvested fruits were assessed for disease symptoms from natural infections and assayed for the accumulation of chitinase and peroxidase, two major pathogenesis-related (PR) proteins induced as a result of systemic acquired resistance (SAR). Harvested fruit from both BTH- or INA-treated plants showed a significant (P < 0.05) reduction in the severity and incidence of post-harvest storage diseases mainly caused by Fusarium, Alternaria and Rhizopus. However, there were no differences in disease severity and the incidence of rots between using four fortnightly foliar sprays of INA or BTH during flowering and fruit development, or a single spray of BTH, 2 weeks before harvest. Each approach showed an equivalent reduction in storage diseases. Plants treated with BABA showed less resistance against powdery mildew in the field and storage rots from natural inoculum, and lower increases in chitinase and peroxidase activities than those treated with INA. In all trials, an additional post-harvest dip with guazatine [0.05% (w/v)] gave a substantial reduction in melon storage rots. Pre-harvest application of INA or BTH reduced the occurrence of powdery mildew and downy mildew on the leaves. Over the three field-experiments, INA had a small phytotoxic effect causing lesion-like symptoms on leaves and affected plant growth, but not yield, at Camden, when applied during flowering and 2 weeks after flowering. However, INA did not produce any phytotoxic effects in the two experiments at Griffith when applied serially, four times to plants after flowering.

Induction of Resistance to Xanthomonas oryzae pv. oryzae in Rice by Benzothiadiazole (BTH)

Systemic acquired resistance induced by benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester (BTH) in rice against bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae was studied. Rice plants (IR 50) pre-treated with BTH showed resistance to a challenge infection with Xanthomonas oryzae pv. oryzae. About 50% reduction in disease intensity was observed in plants treated with BTH at 100 µg a.i./ml. Immunoblot analysis using barley chitinase antiserum revealed the induction of a 35 kDa chitinase in rice in response to treatment with BTH. The results indicate that the BLB resistance can be induced even in genetically susceptible cultivar through application of BTH.

The Arabidopsis ssi1 mutation restores pathogenesis-related gene expression in npr1 plants and renders defensin gene expression salicylic acid dependent.

The Arabidopsis NPR1 gene was previously shown to be required for the salicylic acid (SA)- and benzothiadiazole (BTH)-induced expression of pathogenesis-related (PR) genes and systemic acquired resistance. The dominant ssi1 (for suppressor of SA insensitivity) mutation characterized in this study defines a new component of the SA signal transduction pathway that bypasses the requirement of NPR1 for expression of the PR genes and disease resistance. The ssi1 mutation caused PR (PR-1, BGL2 [PR-2], and PR-5) genes to be constitutively expressed and restored resistance to an avirulent strain of Pseudomonas syringae pv tomato in npr1-5 (previously called sai1) mutant plants. In addition, ssi1 plants were small, spontaneously developed hypersensitive response-like lesions, accumulated elevated levels of SA, and constitutively expressed the antimicrobial defensin gene PDF1.2. The phenotypes of the ssi1 mutant are SA dependent. When SA accumulation was prevented in ssi1 npr1-5 plants by expressing the SA-degrading salicylate hydroxylase (nahG) gene, all of the phenotypes associated with the ssi1 mutation were suppressed. However, lesion formation and expression of the PR genes were restored in these plants by the application of BTH. Interestingly, expression of PDF1.2, which previously has been shown to be SA independent but jasmonic acid and ethylene dependent, was also suppressed in ssi1 npr1-5 plants by the nahG gene. Furthermore, exogenous application of BTH restored PDF1.2 expression in these plants. Our results suggest that SSI1 may function as a switch modulating cross-talk between the SA- and jasmonic acid/ethylene-mediated defense signal transduction pathways.