Transcriptional Association between mRNAs and Their Paired Natural Antisense Transcripts Following Fusarium oxysporum Inoculation in Brassica rapa L

Differences in the transcriptional immune response to Albugo candida between white rust resistant and susceptible cultivars in Brassica rapa L

Albugo candida causing white rust disease decreases the yield of Brassica rapa vegetables greatly. Resistant and susceptible cultivars in B. rapa vegetables have different immune responses against A. candida inoculation, however, the mechanism of how host plants respond to A. candida is still unknown. Using RNA-sequencing, we identified differentially expressed genes (DEGs) between A. candida inoculated [48 and 72 h after inoculation (HAI)] and non-inoculated samples in resistant and susceptible cultivars of komatsuna (B. rapa var. perviridis). Functional DEGs differed between the resistant and susceptible cultivars in A. candida inoculated samples. Salicylic acid (SA) responsive genes tended to be changed in their expression levels by A. candida inoculation in both resistant and susceptible cultivars, but different genes were identified in the two cultivars. SA-dependent systemic acquired resistance (SAR) involving genes were upregulated following A. candida inoculation in the resistant cultivar. Particular genes categorized as SAR that changed expression levels overlapped between A. candida and Fusarium oxysporum f. sp. conglutinans inoculated samples in resistant cultivar, suggesting a role for SAR in defense response to both pathogens particularly in the effector-triggered immunity downstream pathway. These findings will be useful for understanding white rust resistance mechanisms in B. rapa.

Antisense Transcription in Plants: A Systematic Review and an Update on cis-NATs of Sugarcane

Initially, natural antisense transcripts (NATs, natRNAs, or asRNAs) were considered repressors; however, their functions in gene regulation are diverse. Positive, negative, or neutral correlations to the cognate gene expression have been noted. Although the first studies were published about 50 years ago, there is still much to be investigated regarding antisense transcripts in plants. A systematic review of scientific publications available in the Web of Science databases was conducted to contextualize how the studying of antisense transcripts has been addressed. Studies were classified considering three categories: “Natural antisense” (208), artificial antisense used in “Genetic Engineering” (797), or “Natural antisense and Genetic Engineering”-related publications (96). A similar string was used for a systematic search in the NCBI Gene database. Of the 1132 antisense sequences found for plants, only 0.8% were cited in PubMed and had antisense information confirmed. This value was the lowest when compared to fungi (2.9%), bacteria (2.3%), and mice (54.1%). Finally, we present an update for the cis-NATs identified in Saccharum spp. Of the 1413 antisense transcripts found in different experiments, 25 showed concordant expressions, 22 were discordant, 1264 did not correlate with the cognate genes, and 102 presented variable results depending on the experiment.