30 results about "Xanthomonas citri" patented technology

The invention discloses a 1,4-pentadiene-3-ketone derivative with thiophene sulphonate. The derivative is characterized in that the general formula of the derivative is shown in the following formula,wherein R is substituted phenyl or a substituted aromatic heterocyclic group. According to the derivative, 1-(4-hydroxy phenyl)-5-(substituted aryl)-1,4-pentadiene-3-ketone and thiophene sulphonate with good biological activity react to generate the 1,4-pentadiene-3-ketone derivative with the thiophene sulphonate, and when the concentration is 100 mcg / mL and 50 mcg / mL, the plant bacterium inhibition activity of a target compound is measured. It is proved through a bacterium inhibition activity testing result that at the experiment testing concentration, most compounds have good inhibition activity on xanthomonas oryzae, ralstonia solanacearum and xanthomonas citri and can be applied to preparation of an agent for inhibiting plant bacteria.

The invention discloses a method for screening a marker-free deletion mutant of an Xanthomonas citri subsp.citri hfq gene. The method for screening the marker-free deletion mutant of the Xanthomonas citri subsp.citri hfq gene comprises the steps: (1) extracting Xanthomonas citri subsp.citri DNA; (2) constructing an hfq gene deleted recombinant suicide plasmid vector: A, respectively amplifying upstream and downstream flanking sequences of the Xanthomonas citri subsp.citri hfq gene by using primers of Hfq-up-F, Hfq-up-R, Hfq-down-F and Hfq-down-R; B, recycling a PCR fragment; C, connecting a recycled product with a vector pEASY-T1vector; D, converting a connection product into escherichia coli; E, extracting a positive cloning plasmid; F, carrying out double enzyme digestion on upstream / downstream T-vector recombinant plasmid and pK18mobSacB; and G, connecting enzyme digestion products and converting a connection liquid into DH5(alpha) escherichia coli; (3) converting the recombinant suicide plasmid vector into Xanthomonas citri subsp.citri; and (4) screening the mutant by using a sucrose medium method.

The invention discloses a pyrazolyl-oxa(thia)diazole compound containing pyridinium salt, and a preparation method and application thereof. The compound has the structure as shown in the following general formula (I). On the basis of a pyrazolyl-oxa(thia)diazole thioether(oxoether) compound, a pyridinium group capable of improving the biological activity of a target compound is introduced into the system to synthesize a series of pyrazolyl-oxa(thia)diazole oxoether or thioether amphipathic molecules containing the pyridinium salt; moreover, the compound has a good inhibition effect on pathogenic bacteria and fungi, has good inhibition effects on bacteria (bacterial leaf blight of rice, ralstonia solanacearum, xanthomonas citri and the like) and fungi (gibberella zeae, phytophthora infestans, rhizoctonia solani, botrytis cinerea pers, fusarium oxysporum, apple rot pathogenic bacteria and the like), and provides an important scientific base for research, development and creation of novel pesticides.

The invention pertains to a plant cell or a plant having one or more mutations in the promoters of both the alleles for CsLOB1 gene, wherein the one or more mutations are in the promoter binding sites for PthA4 protein from Xanthomonas spp., and wherein the one or more mutations reduce or abolish the binding of the Xanthomonas spp. PthA4 protein on to the binding sites in the promoters of the CsLOB1 genes. Also, a plant cell or a plant having one or more mutations in the coding regions of both the alleles for CsLOB1 gene, wherein the one or more mutations reduce or abolish the binding of the function of CsLOB1 protein are provided. The invention further pertains to the methods of making the plant cell or the plant resistant to infection by Xanthomonas spp.