Functional stacking of three resistance genes against Phytophthora infestans in potato

Functional stacking of broad spectrum resistance (R) genes could potentially be an effective strategy for more durable disease resistance, for example, to potato late blight caused by Phytophthora infestans (Pi). For this reason, three broad spectrum potato R genes (Rpi), Rpi-sto1 (Solanum stoloniferum), Rpi-vnt1.1 (S. venturii) and Rpi-blb3 (S. bulbocastanum) were selected, combined into a single binary vector pBINPLUS and transformed into the susceptible cultivar Desiree. Among the 550 kanamycin resistant regenerants, 28 were further investigated by gene specific PCRs. All regenerants were positive for the nptII gene and 23 of them contained the three Rpi genes, referred to as triple Rpi gene transformants. Detached leaf assay and agro-infiltration of avirulence (Avr) genes showed that the 23 triple Rpi gene transformants were resistant to the selected isolates and showed HR with the three Avr effectors indicating functional stacking of all the three Rpi genes. It is concluded that Avr genes, corresponding to the R genes to be stacked, must be available in order to assay for functionality of each stack component. No indications were found for silencing or any other negative effects affecting the function of the inserted Rpi genes. The resistance spectrum of these 23 triple Rpi gene transformants was, as expected, a sum of the spectra from the three individual Rpi genes. This is the first example of a one-step approach for the simultaneous domestication of three natural R genes against a single disease by genetic transformation

Revealing the Pharmacological Mechanism of Acorus tatarinowii in the Treatment of Ischemic Stroke Based on Network Pharmacology

Aim. Stroke is the second significant cause for death, with ischemic stroke (IS) being the main type threatening human being’s health. Acorus tatarinowii (AT) is widely used in the treatment of Alzheimer disease, epilepsy, depression, and stroke, which leads to disorders of consciousness disease. However, the systemic mechanism of AT treating IS is unexplicit. This article is supposed to explain why AT has an effect on the treatment of IS in a comprehensive and systematic way by network pharmacology. Methods and Materials. ADME (absorbed, distributed, metabolized, and excreted) is an important property for screening-related compounds in AT, which were screening out of TCMSP, TCMID, Chemistry Database, and literature from CNKI. Then, these targets related to screened compounds were predicted via Swiss Targets, when AT-related targets database was established. The gene targets related to IS were collected from DisGeNET and GeneCards. IS-AT is a common protein interactive network established by STRING Database. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were analysed by IS-AT common target genes. Cytoscape software was used to establish a visualized network for active compounds-core targets and core target proteins-proteins interactive network. Furthermore, we drew a signal pathway picture about its effect to reveal the basic mechanism of AT against IS systematically. Results. There were 53 active compounds screened from AT, inferring the main therapeutic substances as follows: bisasaricin, 3-cyclohexene-1-methanol-α,α,4-trimethyl,acetate, cis,cis,cis-7,10,13-hexadecatrienal, hydroxyacoronene, nerolidol, galgravin, veraguensin, 2′-o-methyl isoliquiritigenin, gamma-asarone, and alpha-asarone. We obtained 398 related targets, 63 of which were the same as the IS-related genes from targets prediction. Except for GRM2, remaining 62 target genes have an interactive relation, respectively. The top 10 degree core target genes were IL6, TNF, IL1B, TLR4, NOS3, MAPK1, PTGS2, VEGFA, JUN, and MMP9. There were more than 20 terms of biological process, 7 terms of cellular components, and 14 terms of molecular function through GO enrichment analysis and 13 terms of signal pathway from KEGG enrichment analysis based on P<0.05. Conclusion. AT had a therapeutic effect for ischemic via multicomponent, multitarget, and multisignal pathway, which provided a novel research aspect for AT against IS

An updated conventional- and a novel GM potato late blight R gene differential set for virulence monitoring of Phytophthora infestans

Late blight is an important disease in potato that is caused by the oomycete Phytophthora infestans. In the past, Solanum demissum late blight resistance (R) genes were introgressed into cultivated potato (Solanum tuberosum). Eleven of these resistant plants were selected to characterize the virulence spectrum of individual P. infestans isolates and to monitor the dynamics of virulence in P. infestans populations. These plants are referred to as the Mastenbroek and Black differential sets. It has long been assumed that each differential plant contained one single R gene. In the current study and previous studies, however, most Mastenbroek differential plants were shown to harbor multiple R gene(s), which blurs virulence typing of late blight isolates. In order to acquire more accurate virulence profiles, we extended the Mastenbroek differential set with Solanum spp. plants harboring reduced R gene complexity and with plants containing recently identified R genes from related but different Solanum species. In addition, a differential set of ten Genetically Modified (GM) plants harboring single late blight R genes in the same genetic background (Desiree). By analyzing the virulence spectra of recently collected isolates using both newly described differential sets, we found that the GM Desiree differential set was more accurate for isolate virulence typing than the conventional (extended) differential set. Besides, the GM Desiree differential set was shown to be useful as trap plants to isolate novel P. infestans strains and to monitor virulence towards particular R genes in P. infestans populations `on site´. Legislative restrictions are, however, limiting the use of the GM Desiree differential set