Dual species dynamic transcripts reveal the interaction mechanisms between Chrysanthemum morifolium and Alternaria alternata

Abstract

Background Chrysanthemum (Chrysanthemum morifolium) black spot disease caused by Alternaria alternata is one of the plant’s most destructive diseases. Dual RNA-seq was performed to simultaneously assess their transcriptomes to analyze the potential interaction mechanism between the two species, i.e., host and pathogen. Results C. morifolium and A. alternata were subjected to dual RNA-seq at 1, 12, and 24 h after inoculation, and differential expression genes (DEGs) in both species were identified. This analysis confirmed 153,532 DEGs in chrysanthemum and 14,932 DEGs in A. alternata, which were involved in plant-fungal interactions and phytohormone signaling. Fungal DEGs such as toxin synthesis related enzyme and cell wall degrading enzyme genes played important roles during chrysanthemum infection. Moreover, a series of key genes highly correlated with the early, middle, or late infection stage were identified, together with the regulatory network of key genes annotated in the Plant Resistance Genes database (PRGdb) or Pathogen-Host Interactions database (PHI-base). Highly correlated genes were identified at the late infection stage, expanding our understanding of the interplay between C. morifolium and A. alternata. Additionally, six DEGs each from chrysanthemum and A. alternata were selected for quantitative real-time PCR (qRT-PCR) assays to validate the RNA-seq output. Conclusions Collectively, data obtained in this study enriches the resources available for research into the interactions that exist between chrysanthemum and A. alternata, thereby providing a theoretical basis for the development of new chrysanthemum cultivars with resistance to pathogen.

Evaluation of Five Chrysanthemum morifolium Cultivars against Leaf Blight Disease Caused by Alternaria alternata at Rooting and Seedling Growth Stages

“…Previously, only a few studies have been published on leaf blight disease caused by A. alternata on chrysanthemum. This includes a study in Prayagraj, India [ 36 ], Nanjing, China [ 12 , 21 ], and Greater Cairo, Egypt [ 35 ], the latter using seven cultivars (where ‘Dayangju’, ‘Jinba’, and ‘Chrystal Fresh White’ were among them. In the current study, the histological studies in the cross sections in both leaves and stems showed the highest values of cuticle thickness, cortex thickness, stem diameter, xylem vessel diameter, thickness of leaf epidermis, as well as lamina thickness in ‘Podolsk Purple’.…”

“…can be destructive, causing black spot or leaf blight disease [ 9 ]. Leaf blight disease has severe impacts on chrysanthemum, which results in invaded Alternaria alternata that attacks mature leaves, with a rapid spread through plant tissues, soil, and surrounding air, especially under high temperature conditions [ 21 ]. A. alternata can cause serious damage after infection by secreting fungus toxins and enzymes for cell wall degrading in chrysanthemum tissues.…”

Identification of resistance to black spot disease and potential defense mechanisms in Chrysanthemum-related genera

“…The rooted seedlings were cultured in a 3:1 vermiculite mixture. Seedlings were grown in long-day conditions (16 hours of light, 25℃, relative humidity 75%) (Liu et al, 2021;Liu et al, 2020). Plants with uniform growth were randomly divided into two groups (n = 15): the control group and the treatment group.…”

Jasmonate signaling drives defense responses against Alternaria alternata in chrysanthemum

“…Using transcriptomic analysis, we reported that A. alternata activates the transcription of JA biosynthesis and signaling genes in chrysanthemum [ 31 ]. However, the molecular mechanism associated with JA-induced defense responses against A. alternata in chrysanthemum is largely unknown.…”