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Citral is a mixture of neral and geranial, which are of great interest to the fragrance industry due to its lemon-scented aroma. A newly characterized nerol dehydrogenase of Persicaria minor (PmNeDH) from our recent findings has shown a capacity to convert citral from nerol. Differential gene expression analysis revealed that the expression level of PmNeDH was highly upregulated during early treatment of several stress-related phytohormones i.e. methyl jasmonate (MeJA), salicylic acid (SA) and abscisic acid (ABA). SA and ABA were shown to have a prolonged effect on PmNeDH expression level until second day of treatment. The findings were in agreement with the cis-regulatory elements predicted from the gene promoter. The phylogenetic relationship of PmNeDH with its homologs from the medium-chain dehydrogenases/reductases (MDR) superfamily was also mentioned. In this study, we proposed a possible biological function of PmNeDH gene in P. minor, which might play significant roles in plant defence mechanism.

Amino acid metabolic pathways are involved in the plant immune system. Pipecolic acid (Pip), a lysine‐derived non‐protein amino acid, acts as an important regulator of disease resistance. Here, we report the functions of Pip on tomato disease resistance. Tomato seedlings treated with 0.5 mM Pip showed increased resistance to Pst DC3000 and B. cinerea compared with the control. After pathogen infection, the expression of defence‐related genes increased in plants pretreated with Pip, while reactive oxygen species (ROS) accumulation decreased. These data demonstrated that exogenous application of Pip induced resistance against Pst DC3000 and B. cinerea in tomatoes, possibly through the regulation of ROS accumulation and defence‐related gene expression. [ABSTRACT FROM AUTHOR]

Citral is a mixture of neral and geranial, which are of great interest to the fragrance industry due to its lemon-scented aroma. A newly characterized nerol dehydrogenase of Persicaria minor (PmNeDH) from our recent findings has shown a capacity to convert citral from nerol. Differential gene expression analysis revealed that the expression level of PmNeDH was highly upregulated during early treatment of several stress-related phytohormones i.e. methyl jasmonate (MeJA), salicylic acid (SA) and abscisic acid (ABA). SA and ABA were shown to have a prolonged effect on PmNeDH expression level until second day of treatment. The findings were in agreement with the cis-regulatory elements predicted from the gene promoter. The phylogenetic relationship of PmNeDH with its homologs from the medium-chain dehydrogenases/reductases (MDR) superfamily was also mentioned. In this study, we proposed a possible biological function of PmNeDH gene in P. minor, which might play significant roles in plant defence mechanism. [ABSTRACT FROM AUTHOR]

BACKGROUND: The soybean cyst nematode Heterodera glycines (Ichinohe) is the most devastating pathogen affecting soybean production worldwide. Biocontrol agents have become eco‐friendly candidates to control pathogens. The aim of this study was to discover novel biocontrol agents against H. glycines. RESULTS: Microbacterium maritypicum Sneb159, screened from 804 strains, effectively reduced the number of females in field experiments conducted in 2014 and 2015. The stability and efficiency of H. glycines control by Sneb159 was further assessed in growth chamber and field experiments. Sneb159 decreased H. glycines population densities, especially the number of females by 43.9%–67.7%. To confirm Sneb159 induced plant resistance, a split‐root assay was conducted. Sneb159 induced local and systemic resistance to suppress the penetration and development of H. glycines, and enhanced the gene expression of PR2, PR3b, and JAZ1, involved in the salicylic acid and jasmonic acid pathways. CONCLUSION: This is the first report of M. maritypicum Sneb159 suppressing H. glycines infection. This effect may be the result of Sneb159‐induced resistance. Our study indicates that M. maritypicum Sneb159 is a promising biocontrol agent against H. glycines. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In this study, we investigated the activities of β-1,3-glucanase and peroxidase enzymes in the leaves of pepper cultivar A3 infected with the incompatible strain PC and the compatible strain HX-9 of Phytophthora capsici. The activities of β-1,3-glucanase and peroxidase enzymes substantially increased in the incompatible interactions compared to the compatible interactions. We also analysed the expression patterns of four defence-related genes, including CABPR1 , CABGLU, CAPO1 and CaRGA1, in the leaves and roots of pepper inoculated with different strains of P. capsici. All gene expression levels were higher in the leaves than in the roots. Markedly different expression patterns were observed between incompatible and compatible host-pathogen interactions. In the incompatible interactions, the expression levels of CABPR1 , CABGLU and CAPO1 genes in leaves increased by a maximum of 17.2-, 13.2- and 20.5-fold at 24, 12 and 12 h, respectively, whereas the CaRGA1 gene expression level increased to a lesser degree, 6.0-fold at 24 h. However, in the compatible interactions, the expression levels of the four defence-related genes increased by a maximum of 11.2-, 8.6-, 7.9- and 2.0-fold at 48, 24, 48 and 72 h, respectively. Compared to the leaves, the expression levels of the four defence-related genes were much lower in the roots. The highest levels of mRNA were those of the CABPR1 gene, which increased 5.1-fold at 24 h in the incompatible and 3.2-fold at 48 h in the compatible interactions. The other three genes exhibited lower expression levels in the incompatible and compatible interactions. These results further confirmed that defence-related genes might be involved in the defence response of pepper to P. capsici attack. [ABSTRACT FROM AUTHOR]

Wheat sharp eyespot, primarily caused by a soil-borne fungus Rhizoctonia cerealis, has become one of the most serious diseases of wheat in China. In this study, an ethylene response factor (ERF) gene from a wheat relative Thinopyrum intermedium, TiERF1, was characterized further, transgenic wheat lines expressing TiERF1 were developed, and the resistance of the transgenic wheat lines against R. cerealis was investigated. Southern blotting analysis indicated that at least two copies of the TiERF1 gene exist in the T. intermedium genome. Yeast one-hybrid assay indicated that the activation domain of TiERF1 is essential for activating the transcript of the reporter gene with the GCC-box cis-element. The TiERF1 gene was introduced into a Chinese wheat cultivar, Yangmai12, by biolistic bombardment. Results of PCR and Southern blotting analyses indicated that TiERF1 was successfully integrated into the genome of the transgenic wheat, where it can be passed down from the T0 to T4 generations. Quantitative reverse transcription-PCR analysis demonstrated that TiERF1 could be overexpressed in the stable transgenic plants, in which the expression levels of wheat pathogenesis-related (PR) genes primarily in the ethylene-dependent signal pathway, such as a chitinase gene and a β-1,3-glucanase gene, were increased dramatically. Disease tests indicated that the overexpression of TiERF1 conferred enhanced resistance to sharp eyespot in the transgenic wheat lines compared with the wild-type and silenced TiERF1 plants. These results suggested that the overexpression of TiERF1 enhances resistance to sharp eyespot in transgenic wheat lines by activating PR genes primarily in the ethylene-dependent pathway. [ABSTRACT FROM PUBLISHER]