- Strategies of Nitrosomonas europaea 19718 to Counter Low Dissolved Oxygen and High Nitrite Concentrations

Abstract

Background: Stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases of wheat worldwide. Due to special features of hexaploid wheat with large and complex genome and difficulties for transformation, and of Pst without sexual reproduction and hard to culture on media, the use of most genetic and molecular techniques in studying genes involved in the wheat-Pst interactions has been largely limited. The objective of this study was to identify transcriptionally regulated genes during an incompatible interaction between wheat and Pst using cDNA-AFLP technique Results: A total of 52,992 transcript derived fragments (TDFs) were generated with 64 primer pairs and 2,437 (4.6%) of them displayed altered expression patterns after inoculation with 1,787 up-regulated and 650 down-regulated. We obtained reliable sequences (>100 bp) for 255 selected TDFs, of which 113 (44.3%) had putative functions identified. A large group (17.6%) of these genes shared high homology with genes involved in metabolism and photosynthesis; 13.8% to genes with functions related to disease defense and signal transduction; and those in the remaining groups (12.9%) to genes involved in transcription, transport processes, protein metabolism, and cell structure, respectively. Through comparing TDFs identified in the present study for incompatible interaction and those identified in the previous study for compatible interactions, 161 TDFs were shared by both interactions, 94 were expressed specifically in the incompatible interaction, of which the specificity of 43 selected transcripts were determined using quantitative real-time polymerase chain reaction (qRT-PCR). Based on the analyses of homology to genes known to play a role in defense, signal transduction and protein metabolism, 20 TDFs were chosen and their expression patterns revealed by the cDNA-AFLP technique were confirmed using the qRT-PCR analysis. Conclusion: We uncovered a number of new candidate genes possibly involved in the interactions of wheat and Pst, of which 11 TDFs expressed specifically in the incompatible interaction. Resistance to stripe rust in wheat cv. Suwon11 is executed after penetration has occurred. Moreover, we also found that plant responses in compatible and incompatible interactions are qualitatively similar but quantitatively different soon after stripe rust fungus infection.

Transcriptome Profiling of Rust Resistance in Switchgrass Using RNA‐Seq Analysis

“…We speculated these transcripts represent new candidate genes for rust resistance in switchgrass. Transcripts of unknown function have also been reported in wheat yellow rust and leaf rust resistance studies (Wang et al, 2010; Raman et al, 2011). Out of the identified homologs, 29 are expressed proteins with no known function.…”

“…This was similar to what was reported for leaf rust resistance in wheat ( Triticum aestivum L.), where differential expression between the resistant and susceptible cultivars was found after 48 hpi, with the highest abundance appearing at 96 hpi (Raman et al, 2011). The profusion of the stress‐tolerance‐related transcripts may be attributed to recognition of the pathogen by the host resistance genes before 60 hpi and initiation of the defense mechanism in host cells carrying the resistance gene against the rust pathogen (Bolton, 2009; Wang et al, 2010). We speculate that the expression of genes by the moderately resistant progenies is caused by massive reprogramming of the moderately resistant plant cells to restrict pathogen invasion.…”

“…Plants respond to a pathogen attack through a variety of signaling pathways consisting of a large number of constitutive as well as inducible genes (Van Verk et al, 2009). This phenomenon has been documented in wheat stripe rust ( Puccinia striiformis ) (Wang et al, 2010) and barley powdery mildew ( Blumeria graminis f. sp. hordei )(Caldo et al, 2004), as different sets of genes were expressed during the infection process.…”

TaCIPK10 interacts with and phosphorylates TaNH2 to activate wheat defense responses to stripe rust

“…In our study, the expression of TaNH2 was found to be induced by Pst infection. As a previous study shown (Wang et al ., ), the up‐regulation of host genes during infection may indicate the exploitation of cellular resources and/or the activation of defense responses, suggesting that TaNH2 is involved in wheat resistance. In addition, TaNH2 was shown to positively regulate wheat resistance characterized by decreased necrotic area, reduced ROS accumulation and increased uredia production in TaNH2 ‐knockdown plants (Figure and Figure S15).…”

Transcriptional profiling reveals no response of fungal pathogens to the durable, quantitative Lr34 disease resistance gene of wheat

“…Similar results were described by Wang et al . () where 94 wheat genes were preferentially induced during the compatible interaction compared to the incompatible interaction of stripe rust between 12 to 24 h post‐infection. In addition, rice variety Nipponbare, carrying the resistance gene Pia , showed differential gene expression when infected with the rice blast ( Magnaporthe oryzae ) isolate P91‐15B (compatible interaction) compared to when infected with isolate Ina 86‐137 (incompatible interaction; Kawahara et al ., ).…”