Endophytic fungi infect plant tissues by evading the immune response, potentially stimulating stress-tolerant plant growth. The plant selectively allows microbial colonization to carve endophyte structures through phenotypic genes and metabolic signals. Correspondingly, fungi develop various adaptations through symbiotic signal transduction to thrive in mycorrhiza. Over the past decade, the regulatory mechanism of plant-endophyte interaction has been uncovered. Currently, great progress has been made on plant endosphere, especially in endophytic fungi. Here, we systematically summarize the current understanding of endophytic fungi colonization, molecular recognition signal pathways, and immune evasion mechanisms to clarify the transboundary communication that allows endophytic fungi colonization and homeostatic phytobiome. In this work, we focus on immune signaling and recognition mechanisms, summarizing current research progress in plant-endophyte communication that converge to improve our understanding of endophytic fungi.
1 May 2019 in International Journal of Biological Macromolecules
Hydroxypropylation and cross-linking were carried out on three rice starches with 6.93%, 19.02% and 48.41% AAC respectively. AAC affected the efficiency of modification, with AAC increased, the molar substitution of hydroxypropylated starch decreased while degree of substitution of cross-linked starch increased. Modifications decreased starch relative crystallinity while the impacts were dependent on rice varieties. Starch granules of high AAC rice were liable to be disrupted by modification. High AAC rice starch had better processability, modifications have more pronounced influences on starch properties of high AAC. Different modifications showed different influences on starch properties, cross-linking decreased AAC content, pasting clarity and swelling power of all three starches, while hydroxypropylation increased pasting clarity and swelling power of high AAC starch. High-degree modifications decreased starch digestibility, higher-CLD crosslinked starch showed constant digestion rate and might be a suitable modification for produce starchy food for equilibrium glucose level.
Summary: Emerging evidence indicates a close connection between cell‐cycle progression and the plant immune responses. In Arabidopsis, MODIFIER OF snc1‐1 (MOS1) modulates a number of processes including endoreduplication and plant disease resistance, but the molecular mechanism underlying this modulation was not fully understood. Here, we provide biochemical and genetic evidence that TEOSINTE BRANCHED 1, CYCLOIDEA, PCF1 (TCP) transcription factors TCP15 and its homologues are mediators of MOS1 function in the immune response and are likely to be also involved in cell‐cycle control. MOS1 and TCP proteins have a direct physical interaction. They both bind to the promoter of the immune receptor gene SUPRESSOR OF npr1‐1,CONSTITUTIVE 1 (SNC1) and modulate its expression and consequently immune responses. MOS1 and TCP15 both affect the expression of cell‐cycle genes D‐type CYCLIN 3;1 (CYCD3;1), which may mediate the MOS1 function in cell‐cycle modulation. In addition, CYCD3;1 overexpression upregulates immune responses, and SNC1 expression. This study investigated and revealed a role for MOS1 in transcriptional regulation through TCP15 and its homologues. This finding suggests the coordination of cell‐cycle progression and plant immune responses at multiple levels.
Cymbidium is a genus of 68 species in the orchid family, with extremely high ornamental value. Marker-assisted selection has proven to be an effective strategy in accelerating plant breeding for many plant species. Analysis of cymbidiums genetic background by molecular markers can be of great value in assisting parental selection and breeding strategy design, however, in plants such as cymbidiums limited genomic resources exist. In order to obtain efficient markers, we deep sequenced the C. ensifolium transcriptome to identify simple sequence repeats derived from gene regions (genic-SSR). The 7,936 genic-SSR markers were identified. A total of 80 genic-SSRs were selected, and primers were designed according to their flanking sequences. Of the 80 genic-SSR primer sets, 62 were amplified in C. ensifolium successfully, and 55 showed polymorphism when cross-tested among 9 Cymbidium species comprising 59 accessions. Unigenes containing the 62 genic-SSRs were searched against Non-redundant (Nr), Gene Ontology database (GO), eukaryotic orthologous groups (KOGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The search resulted in 53 matching Nr sequences, of which 39 had GO terms, 18 were assigned to KOGs, and 15 were annotated with KEGG. Genetic diversity and population structure were analyzed based on 55 polymorphic genic-SSR data among 59 accessions. The genetic distance averaged 0.3911, ranging from 0.016 to 0.618. The polymorphic index content (PIC) of 55 polymorphic markers averaged 0.407, ranging from 0.033 to 0.863. A model-based clustering analysis revealed that five genetic groups existed in the collection. Accessions from the same species were typically grouped together; however, C. goeringii accessions did not always form a separate cluster, suggesting that C. goeringii accessions were polyphyletic. The genic-SSR identified in this study constitute a set of markers that can be applied across multiple Cymbidium species and used for the evaluation of genetic relationships as well as qualitative and quantitative trait mapping studies. Genic-SSR’s coupled with the functional annotations provided by the unigenes will aid in mapping candidate genes of specific function.