Global Transcriptomic Changes Induced by Infection of Cucumber (Cucumis sativus L.) with Mild and Severe Variants of Hop Stunt Viroid

Abstract

Fifteen years after transfer to hops, hop stunt viroid-grapevine (HSVd-g) was replaced by HSVd-hop (HSVd-h), a sequence variant that contains changes at five different positions. HSVd-g54 is a laboratory mutant derived from HSVd-g that differs from its progenitor by a single G to A substitution at position 54. While infection by HSVd-h induces only mild stunting in cucumber (Cucumis sativus L.), HSVd-g54 induces much more severe symptoms in this indicator host. Comparison of transcriptome profiles of cucumber infected with HSVd-h or HSVd-g54 with those of mock-inoculated controls obtained by whole transcriptome shotgun sequencing revealed that many genes related to photosynthesis were down-regulated following infection. In contrast, genes encoding RNA-dependent RNA polymerase 1 (CsRDR1), especially CsRDR1c1 and CsRDR1c2, as well as those related to basal defense responses were up-regulated. Expression of genes associated with phytohormone signaling pathways were also altered, indicating that viroid infection initiates a complex array of changes in the host transcriptome. HSVd-g54 induced an earlier and stronger response than HSVd-h, and further examination of these differences will contribute to a better understanding of the mechanisms that determine viroid pathogenicity.

Transcriptomic Analysis Reveals Cu/Zn SODs Acting as Hub Genes of SODs in Hylocereus undatus Induced by Trypsin during Storage

“…It has been confirmed that trypsin significantly impacts on the free radical scavenging activities of flavonoids [8]. Our previous results also showed that trypsin scavenges superoxide anions (O 2 • − ) and protects cells [9].In the area of phytopathology, transcriptomic analysis has been successful used on lots of plants [10][11][12][13]. However, few of transcriptomic works have been focused on the preservation of fruits.…”

Time-series expression profiling of sugarcane leaves infected withPuccinia kuehniireveals an ineffective defense system leading to susceptibility

“…Photosynthesis-related genes, such as the photosystem ones, can be downregulated by 522 biotic agents [114]. Furthermore, microarray gene expression studies of Arabidopsis and photosynthesis genes for weeks after infection [33,116]. This is in agreement with 530 the physiological impact of orange rust, because measures of chlorophyll content and net 531 photosynthetic rate of sugarcane leaves decrease according to susceptibility to P.…”

“…In contrast, phenylpropanoid biosynthesis was enriched at 12 hai in 449 the compatible interaction of an apple cultivar and A. alternata [38]. Furthermore, this 450 pathway was enriched with downregulated genes in cucumber infected by a mutant of 451 hop stunt viroid-grapevine at 28 dai [33]. In sugarcane smut, tyrosine accumulation is 452 characteristically associated with phenylpropanoid biosynthesis [104].…”

“…To achieve an overview of the showed temporary activation at 36 hai of genes encoding these last two enzymes [103]. 445 Several authors noted that genes encoding enzymes of the phenylpropanoid pathway are 446 differentially expressed in the first hours or many days after infection [33,38,39,42]. 447 Other authors observed that upregulation of these genes can be associated with 448 resistance [40,90].…”

Impaired expression of chloroplast HSP90C chaperone activates plant defense responses leading to a disease symptom-like phenotype

“…Exploiting the advantage in the present study, we explored the early molecular changes leading to the development of chlorosis using RNA-seq analysis. Although studies have shown the transcriptome changes in virus- and viroid-infected plants (Mochizuki et al ., 2014; Xia et al ., 2017; Zheng et al ., 2017), the strength of the present study is that we could detect any changes that precede detectable chlorosis.…”