Targeted spatio-temporal expression based characterization of state of infection and time-point of maximum defense in wheat NILs during leaf rust infection

Abstract

Leaf rust, caused by the fungus Puccinia triticina, is the most devastating disease of wheat worldwide, which sometimes becomes epidemic. The pathogen evolves into new strains, making its control difficult. Though more than 60 leaf rust resistant genes are now known, only limited insight is available into the molecular mechanism involved in this host pathogen interaction. In the present study, quantitative real-time PCR based differential gene expression profiling was examined for five target genes encoding for chitinase3, β-1,3/1,4 glucanase, thaumatin-like protein, peroxidase2 and mitogen activated protein kinase1 to unravel their coordinated action during compatible and incompatible interaction, to inhibit the pathogen progression and to identify the time-period of maximum defense activity. Spatio-temporal expression profiling suggested that the maximum defense activity occurred at 12-24 hours post inoculation, whereas the state of infection and degree of resistance was predicted using coordinated unique expression signatures of target genes. The significant differences of targeted gene expression between resistant mock inoculated, resistant infected and susceptible infected plants were evaluated using t test at significance level of p < 0.01. The differences occurred can be attributed to the presence of seedling leaf rust resistance Lr28 gene, which facilitated prevention of leaf rust infection in resistant wheat plants.

Comparative genomics of six Juglans species reveals disease‐associated gene family contractions

“…The observed loss of Chitinase‐3 (Cht3) (OG0001222) in J. hindsii is consistent with the loss of FERONIA and RWA2. Cht3 (along with glucanase and thaumatin‐like protein) are aspects of plant response to fungal invasion (Singh et al , ), and was found to be under positive selection in the additional Juglans species (Table S7). If the loss of FERONIA and RWA2 do correspond to a weakened compatible host signature, the decreased incidence of fungal infection would render such defense responses inessential.…”

De Novo Assembled Wheat Transcriptomes Delineate Differentially Expressed Host Genes in Response to Leaf Rust Infection

“…After inoculation, misting of the growth chamber was performed to create conditions of high humidity (>90%) for 24 hours post inoculation (hpi) in the dark to facilitate infection. Thereafter, the plants were maintained in a standard growth chamber as mentioned earlier [ 32 ]. The wheat leaf samples (5 leaves from separate plants of each treatment) were collected at 24 hpi and immediately dipped in liquid nitrogen and kept for RNA isolation ( Fig 1 ).…”

Discovery of Novel Leaf Rust Responsive microRNAs in Wheat and Prediction of Their Target Genes

“…Puccinia triticina pathotype 77-5, the most predominant and devastating pathotype in all parts of the Indian subcontinent, was selected as experimental pathogen. Plant growth, pathogen inoculum preparation, inoculation of the pathogen, and infectivity screening were performed at the National Phytotron Facility, IARI, New Delhi, exactly as mentioned in Singh et al [35]. …”

“…Total RNA was isolated using TRI Reagent (Molecular Research Center Inc., USA) as recommended by manufacturer. The RNA isolation time-point was based on earlier studies on development of infection structures [36] and activation of resistant signaling genes [35, 37]. The integrity of the isolated RNAs was confirmed on an Agilent Bioanalyser 2100.…”