Medicinal plants are beneficial to human health. However,most of the major producing regions of medicinal plants suffer from rust disease,which threatens the yield and quality of Chinese medicinal materials,thus causes huge economic loss,and hinders the sustainable development of the Chinese medicine industry. By the end of 2020,rust disease had been reported in medicinal plants of 76 species and 33 families. In the 76 species,79 rust pathogens were detected. The majority of these pathogens belonged to Puccinia( 33,39. 24%),Coleosporium( 14,15. 19%),and Aecidium( 11,13. 92%). Of these 79 rust pathogens,10 were autoecious and 13 were heteroecious. Through literature research,this study reviewed the symptoms,pathogen species,severity and distribution,prevalence and occurrence conditions,and control measures of rust disease in medicinal plants,and thereby summarized the research status of rust disease in medicinal plants and the gap with other plants,which is expected to serve as a reference for further research on rust disease in medicinal plants.
Basidiomycota/genetics* ; Humans ; Plant Diseases ; Plants, Medicinal

The cultivation and production of cucumber are seriously affected by downy mildew caused by Pseudoperonospora cubensis. Downy mildew damages leaves, stems and inflorescences, and then reduces the yield and quality of cucumber. This review summarized the research advances in cucumber downy mildew, including pathogen detection and defense pathways, regulatory factors, mining of pathogens-resistant candidate genes, proteomic and genomic analysis, and development of QTL remarks. This review may facilitate clarifying the resistance mechanisms of cucumber to downy mildew.
Cucumis sativus/genetics* ; Oomycetes/genetics* ; Peronospora ; Plant Diseases/genetics* ; Proteomics

Leymus racemosus had a high resistant capacity to wheat scab (Fusarum head blight). The transfer of scab resistant gene from L. racemosus to Triticum aestivum is of great significance for broadening the germplasm of wheat resistance. To obtain Triticum aestivum-Leymus racemosus translocation line with scab resistance, we irradiated the pollen of T. aestivum-L. racemosus disomic addition line DA7Lr by ⁶⁰Co-γ-rays 1 200 R (100 R/min) prior to pollinating to emasculation T. aestivum cv. Chinese Spring. One plant with one translocation chromosome was detected in the M1 by GISH. The plant with one translocation chromosome was self-pollinated, and at meiotic metaphase I its progenies with two translocation chromosomes were analyzed for chromosome pairing behavior in their pollen mother cells (PMCs). One rod bivalent was observed at meiotic metaphase I, indicating that the plant with two translocation chromosomes was one translocation homozygote. Sequential GISH-FISH analysis, using Oligo-pAs1-2 and Oligo-pSc119.2-2 as probe, translocation line was confirmed as T6DL·7LrS. The translocation line had higher resistance to wheat scab and feasibility to be used as a new source in wheat breeding resistant to scab disease.
Chromosomes, Plant ; Disease Resistance ; genetics ; In Situ Hybridization, Fluorescence ; Plant Breeding ; Plant Diseases ; genetics ; Poaceae ; genetics ; Pollen ; Translocation, Genetic ; Triticum ; genetics

G46B is a promising holding line used for three-lines breeding strategy in hybrid rice, but it is susceptible to blast disease caused by Pyricularia grisea. To improve its blast resistance, three rice varieties, Digu, BL-1, and Pi-4, with blast resistance genes, Pi-d(t), Pi-b, and Pi-ta2, respectively, were used to be crossed with G46B, and 15 plants with these three blast resistance genes, Pi-d(t)1, Pi-b, and Pi-ta2, were selected from their F2 and B1C1 populations via a marker-aided crossing procedure. Among them, four plants were heterozygotes in the three resistance genes, with the genotype of Pi-d(t)1 pi-d(t)/Pi-b pi-b/ Pi-ta2 pi-ta2; ten plants were heterozygotes in two of the three resistance genes, of which six with the genotype of Pi-d(t)1 Pi-d(t)1/Pi-b pi-b/Pi-ta2 pi-ta2, three with the genotype of Pi-d(t)1 pi-d(t)1/Pi-b pi-b/Pi-ta2 Pi-ta2, and one with the genotype of Pi-d(t)1pi-d(t)1/Pi-b Pi-b/Pi-ta2 pi-ta2; and only one plant was homozygote in two of the three resistance genes with the genotype of Pi-d(t)1 Pi-d(t)/Pi-b pi-b/Pi-ta2 Pi-ta2. These results demonstrate the capacity of maker-assisted selection (MAS) in gene pyramiding for rice blast resistance and its enhancement for the efficiency in rice resistance breeding.
Crosses, Genetic ; Genes, Plant ; Genetic Markers ; Genotype ; Oryza ; genetics ; Plant Diseases ; genetics ; Selection, Genetic

The aquatic grass Zizania latifolia grows symbiotically with the fungus Ustilago esculenta producing swollen structures called Jiaobai, widely cultivated in China. A new disease of Z. latifolia was found in Zhejiang Province, China. Initial lesions appeared on the leaf sheaths or sometimes on the leaves near the leaf sheaths. The lesions extended along the axis of the leaf shoots and formed long brown to dark brown streaks from the leaf sheath to the leaf, causing sheath rot and death of entire leaves on young plants. The pathogen was isolated and identified as the bacterium Pantoea ananatis, based on 16S ribosomal RNA (rRNA) gene sequencing, multilocus sequence analysis (atpD (β-subunit of ATP synthase F1), gyrB (DNA gyrase subunit B), infB (translation initiation factor 2), and rpoB (β‍-subunit of RNA polymerase) genes), and pathogenicity tests. Ultrastructural observations using scanning electron microscopy revealed that the bacterial cells colonized the vascular tissues in leaf sheaths, forming biofilms on the inner surface of vessel walls, and extended between vessel elements via the perforated plates. To achieve efficient detection and diagnosis of P. ananatis, species-specific primer pairs were designed and validated by testing closely related and unrelated species and diseased tissues of Z. latifolia. This is the first report of bacterial sheath rot disease of Z. latifolia caused by P. ananatis in China.
Pantoea/genetics* ; Plant Diseases/microbiology* ; Poaceae/microbiology* ; Virulence

Rice bacterial leaf streak,caused by Xanthomonas oryzae pv. oryzicola is a destructive bacterial disease in China. Single-gene resistance to X. oryzae pv. oryzicola has not been found in rice germplasm. A cloned non-host gene from maize with resistance to bacterial leaf streak, Rxo1, was transferred into four Chinese rice varieties through an Agrobacterium-mediated system, including Zhonghua11, 9804, C418 and Minghui86. PCR and Southern analysis of the transgenic plants revealed the integration of the Rxo1 gene into the rice genomes. The integrated Rxo1 was stably inherited, and segregated in a 3:1 (Resistance:Susceptible) ratio in the selfed T1 generations derived from some T0 plants, indicating that Rxo1 inherited as a dominate gene in rice. Transgenic T0 plants and PCR-positive T1 plants were resistant to X. oryzae pv. oryzicola on the basis of artificial inoculation.
Bacterial Proteins ; genetics ; metabolism ; Genes, Plant ; genetics ; Oryza ; genetics ; Plant Diseases ; genetics ; microbiology ; Plants, Genetically Modified ; genetics ; Rhizobium ; genetics ; Transformation, Genetic ; Xanthomonas ; genetics ; Zea mays ; genetics ; microbiology

A wheat stripe rust resistance gene was screened out from Aegilops tauschii which is relative genera of wheat species, broadening the genetic basis of the anti-disease character of wheat species. By hybridizing diversed Ae. Tauschii species, which is either resistant or susceptible to wheat stripe rust, a dominant wheat stripe rust resistance gene was detected from Ae. Tauschii (Coss.) Schmal Y206. The novel gene was temporarily designated as YrY206. By bulk segregation analysis, four microsatellite markers Wmc11a, Xgwm71c, Xgwm161 and Xgwm183 were found to be linked to YrY206 with genetic distances of 4.0, 3.3, 1.5 and 9.3 cM, respectively. According to the locations of the linked markers, the resistance gene was located on chromosome 3DS. Based on the chromosomal location and the resistance pattern of the gene, YrY206 should be a novel stripe rust resistance gene.
Basidiomycota ; pathogenicity ; Chromosome Mapping ; Immunity, Innate ; genetics ; Microsatellite Repeats ; genetics ; Plant Diseases ; genetics ; microbiology ; Plant Proteins ; genetics ; Poaceae ; genetics ; microbiology ; Triticum ; genetics ; microbiology

With the development of structural and functional genomics, nowadays specific plant genome and transcriptome sequences can be cloned much easier and faster. Next step is to identify the functions of different genes and regulating elements to unravel the genetic mechanisms behind plant growth and development. Expression and its regulation are the language and dynamic property of genetic material, so expression and regulation analysis of target genes and sequences in plant cell is the basis for function study. Besides stable genetic transformation, plant transient expression system gains broad application in recent years, and its combination with other new technologies as gene shuffling, VIGS and RNAi plays a more and more important role in plant functional genomics.
Gene Expression Profiling ; Genome, Plant ; genetics ; Genomics ; methods ; trends ; Immunity, Innate ; genetics ; Plant Diseases ; genetics ; Plants ; genetics ; Plants, Genetically Modified ; genetics ; RNA Interference

Genetic improvement for drought stress tolerance in rice involves the quantitative nature of the trait, which reflects the additive effects of several genetic loci throughout the genome. Yield components and related traits under stressed and well-water conditions were assayed in mapping populations derived from crosses of AzucenaxIR64 and AzucenaxBala. To find the candidate rice genes underlying Quantitative Trait Loci (QTL) in these populations, we conducted in silico analysis of a candidate region flanked by the genetic markers RM212 and RM319 on chromosome 1, proximal to the semi-dwarf (sd1) locus. A total of 175 annotated genes were identified from this region. These included 48 genes annotated by functional homology to known genes, 23 pseudogenes, 24 ab initio predicted genes supported by an alignment match to an EST (Expressed sequence tag) of unknown function, and 80 hypothetical genes predicted solely by ab initio means. Among these, 16 candidate genes could potentially be involved in drought stress response.
Disasters ; Expressed Sequence Tags ; Gene Expression Regulation, Plant ; genetics ; Gene Library ; Genes, Plant ; genetics ; Genome, Plant ; Oryza ; genetics ; Physical Chromosome Mapping ; Plant Diseases ; genetics ; Quantitative Trait Loci ; genetics ; Signal Transduction ; Water ; metabolism

Gummy stem blight, a plant disease caused by Didymella bryoniae, is one of the major diseases in melon. The disease can seriously reduce melon yield and quality. However, little information is available on the genetics and functional genomics of the fungal pathogen. In this study, we developed an Agrobacterium-mediated transformation system for D. bryoniae by using a universal pathogenic isolate DB11 and the Agrobacterium tumefaciens strain C58C1 carrying plasmid pBIG2RHPH2 harboring the hygromycin B phosphotransferase gene (hph). Total 45 transformants could be obtained per 1 x 10(5) spores when 1 x 10(6) spores per milliliter of D. bryoniae spore suspension were cocultivated with Agrobacterium cells at OD600 = 0.15 for 48 h in the presence of induction medium (pH 5.2) containing acetosyringone at 200 microg/mL and selection medium contained 100 microg/mL of hygromycin B and 200 microg/mL of cefotaxime sodium, ampicillin and tetracycline, respectively. The transformants were stable when grown on PDA medium without hygromycin B for five times and were verified by PCR amplification with the hph primers and by Southern blot analysis with the hph probe. The transformation system will be useful for further studies of functional genes in D. bryoniae.
Agrobacterium tumefaciens ; genetics ; Ascomycota ; genetics ; Cucumis melo ; microbiology ; Plant Diseases ; microbiology ; Plants, Genetically Modified ; Transformation, Genetic