Project description:Abscisic acid (ABA) has an important role in the responses of plants to pathogens due to its ability to induce stomatal closure and interact with salicylic acid (SA) and jasmonic acid (JA). WRKY transcription factors serve as antagonistic or synergistic regulators in the response of plants to a variety of pathogens. Here, we demonstrated that CmWRKY15, a group IIa WRKY family member, was not transcriptionally activated in yeast cells. Subcellular localization experiments in which onion epidermal cells were transiently transfected with CmWRKY15 indicated that CmWRKY15 localized to the nucleus in vivo. The expression of CmWRKY15 could be markedly induced by the presence of Alternaria tenuissima inoculum in chrysanthemum. Furthermore, the disease severity index (DSI) data of CmWRKY15-overexpressing plants indicated that CmWRKY15 overexpression enhanced the susceptibility of chrysanthemum to A. tenuissima infection compared to controls. To illustrate the mechanisms by which CmWRKY15 regulates the response to A. tenuissima inoculation, the expression levels of ABA-responsive and ABA signaling genes, such as ABF4, ABI4, ABI5, MYB2, RAB18, DREB1A, DREB2A, PYL2, PP2C, RCAR1, SnRK2.2, SnRK2.3, NCED3A, NCED3B, GTG1, AKT1, AKT2, KAT1, KAT2, and KC1were compared between transgenic plants and controls. In summary, our data suggest that CmWRKY15 might facilitate A. tenuissima infection by antagonistically regulating the expression of ABA-responsive genes and genes involved in ABA signaling, either directly or indirectly.

| S-EPMC4658048 | biostudies-literature

Unconventional ST2- and CD127-negative lung ILC2 populations are induced by Alternaria

Project description:Background: Alternaria exposure is associated with severe asthma in humans. Alternaria exposure in mice potently activates group 2 innate lymphoid cells (ILC2s) via the IL-33/ST2 axis and causes ILC2s to robustly secrete type 2 cytokines. Objective: Our aim was to determine whether conventionally used ILC2 markers, ST2 (IL-33R) and CD127 (IL-7Ra), were sufficient to identify all Th2-cytokine producing ILCs after Alternaria exposure. Methods: Mice received intranasal Alternaria for three days prior to analysis. Lung ILCs were identified by flow cytometry as CD45+Lineage−Thy1.2+ lymphocyte-sized cells, divided into four subsets based on ST2 and CD127 expression, and stained for intracellular cytokines and transcription factors. Sort-purified ILC subpopulations were also analyzed by RNA sequencing and qPCR. Results: Alternaria exposure led to accumulation of all ILC populations regardless of ST2 or CD127 expression. Nearly half of the GATA-3+, IL-5+, and IL-13+ ILCs were “unconventional” as they were either single or double negative for ST2/CD127. Further, these populations upregulated CD25, KLRG1, and ICOS after Alternaria challenge. Some activated unconventional IL-5+ ILC2s also produced IFNγ and IL-17A. In addition to shared ILC2 transcripts (Gata3, Il5, Il13) in all populations, RNA-seq further identified novel transcripts enriched in each subset. Finally, transcripts from all populations that correlated best with IL-5 and IL-13 production included Tnfrsf18, Ffar2, and Pde4b. Conclusions: Unconventional ST2- and CD127-negative mouse lung ILC2 populations are induced by Alternaria. Thus, commonly used lung ILC2 identification methods based on ST2 and CD127 do not accurately account for the total ILC2 burden and may exclude nearly half of these cells.

2019-08-22 | GSE136156 | GEO

Alternaria alternata

Project description:Genomic and Transcriptomic Characterization of Alternaria alternata During Infection

| PRJNA895027 | ENA