New species of Septoria associated with leaf spot diseases in Iran

Effect of Warming on Soil Fungal Community Along Altitude Gradients in a Subalpine Meadow

The subalpine grassland ecosystem is sensitive to climatic changes. Previous studies investigated the effects of warming on grassland ecosystems at a single altitude, with little information about the response of subalpine meadows to warming along altitude gradients. This study aimed to evaluate the effects of warming on aboveground grass, belowground soil properties, and fungal community along altitude gradients in the subalpine meadow of Mount Wutai using the high-throughput sequencing method. Warming reduced the restriction of low temperatures on the growth of subalpine grass, resulting in increasing grass biomass, community height, and coverage. More grass biomass led to higher soil organic carbon resources, which primarily affected fungal community composition following warming. Warming might induce more stochastic processes of fungal community assembly, increasing fungal diversity at low altitudes. In contrast, warming triggered more deterministic processes to decrease fungal diversity at medium and high altitudes. Warming might improve the efficiency of soil nutrient cycling and organic matter turnover by increasing the relative abundance of soil saprotrophs and improving fungal network connectivity. The relative abundance of certain grass pathogens significantly increased following warming, thereby posing potential risks to the sustainability and stability of subalpine meadow ecosystems. Overall, this study comprehensively evaluated the response of the subalpine meadow ecosystems to warming along altitude gradients, clarifying that warming changes soil fungal community composition at different altitudes. The long-term monitoring of pathogen-related shifts should be conducted in subalpine meadow ecosystem following warming. This study provided significant scientific insights into the impact of future climatic changes on subalpine ecosystems.

Editing Metabolism, Sex, and Microbiome: How Can We Help Poplar Resist Pathogens?

Poplar (Populus) is a genus of woody plants of great economic value. Due to the growing economic importance of poplar, there is a need to ensure its stable growth by increasing its resistance to pathogens. Genetic engineering can create organisms with improved traits faster than traditional methods, and with the development of CRISPR/Cas-based genome editing systems, scientists have a new highly effective tool for creating valuable genotypes. In this review, we summarize the latest research data on poplar diseases, the biology of their pathogens and how these plants resist pathogens. In the final section, we propose to plant male or mixed poplar populations; consider the genes of the MLO group, transcription factors of the WRKY and MYB families and defensive proteins BbChit1, LJAMP2, MsrA2 and PtDef as the most promising targets for genetic engineering; and also pay attention to the possibility of microbiome engineering.

Update of pistachio leaf spot caused by Septoria pistaciarum in light of new taxonomic advances in Italy

Septoria leaf spot is one the most widespread disease affecting pistachio (Pistacia vera) in countries of the Mediterranean region. Traditionally, three species have been associated with pistachio, including Septoria pistaciae, Septoria pistaciarum and S. pistacina. However, recent taxonomic studies have reordered and clarified the status of Septoria and septoria-like pathogens affecting pistachio. In our study, field surveys conducted in the traditional Sicilian pistachio production area of Bronte revealed the presence of trees showing characteristic septoria-like leaf spot. Collected isolates were morphologically and molecularly characterized. Morphological characterization was based on conidia measurements and evaluation of mycelial growth on different artificial media. Tested media included CMA, MEA, OA, PDA, and SNA. Phylogenetic analysis was conducted on a multi-locus approach (ITS + tef1 + tub2) based on Maximum Parsimony and Maximum Likelihood. Results showed that our isolates clustered with S. pistaciarum. Pathogenicity test was conducted in the field using conidia suspensions in order to fulfill Koch's postulates. Presence of characteristic rounded spots and pycnidia was evaluated on the inoculated leaves 9 and 23 days after inoculation. This study represents the first update on S. pistaciarum in Italy since its first identification in 1934.

Occurrence and Characterization of Leaf Spot Caused by Septoria melissae on Lemon Balm in Korea

Leaf spot on lemon balm is frequently observed in Korea, causing considerable damage to crops. In 2014 and 2015, the occurrence of leaf spot was observed in several production greenhouses at Suwon, Gongju, and Namwon in Korea. Symptoms on lower leaves initially developed as small, distinct, discolored lesions, which enlarged progressively turning into dark brown, angular spots surrounded by purplish-brown margins. Based on the morphological characteristics and sequence analysis of actin (ACT), translation elongation factor 1-alpha (EF-1α), internal transcribed spacer (ITS), 28S nrDNA (LSU), and RNA polymerase II second largest subunit (RPB2), the fungus associated with the lemon balm leaf spot was determined as Septoria melissae. To the best of our knowledge, this is the first report of lemon balm leaf spot caused by S. melissae in Asia as well as in Korea.