Wheat blast: from its origins in South America to its emergence as a global threat.

Wheat blast was first reported in Brazil in 1985. It spread rapidly across the wheat cropping areas of Brazil to become the most important biotic constraint on wheat production in the region. The alarming appearance of wheat blast in Bangladesh in 2016 greatly increased the urgency to understand this disease, including its causes and consequences. Here, we summarize the current state of knowledge of wheat blast and aim to identify the most important gaps in our understanding of the disease. We also propose a research agenda that aims to improve the management of wheat blast and limit its threat to global wheat production.

Novel Insights Into the Early Stages of Ratoon Stunting Disease of Sugarcane Inferred from Transcript and Protein Analysis.

Despite of the importance of ratoon stunting disease, little is known on the responses of sugarcane to its causal agent, the vascular bacterial endophyte Leifsonia xyli subsp. xyli. The transcriptome and proteome of young plants of a susceptible cultivar with no symptoms of stunting but with relative low and high bacterial titers were compared at 30 and 60 days after inoculation. Increased bacterial titers were associated with alterations in the expression of 267 cDNAs and in the abundance of 150 proteins involved in plant growth, hormone metabolism, signal transduction and defense responses. Some alterations are predicted to benefit the pathogen, such as the up-regulation of genes involved in the synthesis of methionine. Also, genes and proteins of the cell division cycle were all down-regulated in plants with higher titers at both times. It is hypothesized that the negative effects on cell division related to increased bacterial titers is cumulative over time and its modulation by other host and environmental factors results in the stunting symptom.