Evolutionary and Epidemiological Insights from Historical and Modern Genomes of pv. , the Causal Agent of Bacterial Leaf Streak of Rice.

pv. () causes bacterial leaf streak (BLS) of rice. This disease represents a major constraint for rice production, which is a crop feeding more than half of the world's population.

Closing the information gap between the field and scientific literature for improved disease management- with a focus on rice and bacterial blight.

A path to sustainably reduce world hunger, food insecurity, and malnutrition is to close the crop yield gap, particularly, losses due to pathogens. Breeding resistant crops is key to achieving this goal, an effort requiring collaboration among stakeholders, scientists, breeders, farmers and policymakers. During a disease outbreak, epidemiologists survey the occurrence of a disease after which pathologists investigate mechanisms to stop an infection.

Comparative transcriptomics reveals a highly polymorphic Xanthomonas HrpG virulence regulon.

Background: Bacteria of the genus Xanthomonas cause economically significant diseases in various crops. Their virulence is dependent on the translocation of type III effectors (T3Es) into plant cells by the type III secretion system (T3SS), a process regulated by the master response regulator HrpG. Although HrpG has been studied for over two decades, its regulon across diverse Xanthomonas species, particularly beyond type III secretion, remains understudied.

First report of Cassava Bacterial Blight caused by pv. in the Amazonian forest of Ecuador.

pv. () is a plant pathogenic bacterium known as the causal agent of cassava bacterial blight (CBB). CBB is the most limiting bacterial disease affecting cassava ( Crantz), characterized by diverse symptoms including angular water-soaked leaf lesions, blight, wilting, stem exudates, stem cankers and dieback.

Genome editing of an African elite rice variety confers resistance against endemic and emerging pv. strains.

Bacterial leaf blight (BB) of rice, caused by pv. (), threatens global food security and the livelihood of small-scale rice producers. Analyses of collections from Asia, Africa and the Americas demonstrated complete continental segregation, despite robust global rice trade.

A minisatellite-based MLVA for deciphering the global epidemiology of the bacterial cassava pathogen Xanthomonas phaseoli pv. manihotis.

Cassava Bacterial Blight (CBB) is a destructive disease widely distributed in the different areas where this crop is grown. Populations studies have been performed at local and national scales revealing a geographical genetic structure with temporal variations. A global epidemiology analysis of its causal agent Xanthomonas phaseoli pv.

CRISPRi in Xanthomonas demonstrates functional convergence of transcription activator-like effectors in two divergent pathogens.

Functional analysis of large gene families in plant pathogens can be cumbersome using classical insertional mutagenesis. Additionally, Cas9 toxicity has limited the application of CRISPR-Cas9 for directed mutagenesis in bacteria. Here, we successfully applied a CRISPR interference strategy to investigate the cryptic role of the transcription activator-like effector (tale) multigene family in several plant-pathogenic Xanthomonas bacterial species, owing to their contribution to pathogen virulence.

The Complete Genome Resource of pv. CIX2779 Includes the First Sequence of a Plasmid for an African Representative of This Rice Pathogen.

The bacterial plant pathogen pv. is responsible for the foliar rice bacterial blight disease. Genetically contrasted, continent-specific, sublineages of this species can cause important damages to rice production both in Asia and Africa.

The Rice Locus Is a Bidirectional Target of the African pv. Major Transcription Activator-like Effector TalC but Does Not Contribute to Disease Susceptibility.

pv. () strains that cause bacterial leaf blight (BLB) limit rice () production and require breeding more resistant varieties. Transcription activator-like effectors (TALEs) activate transcription to promote leaf colonization by binding to specific plant host DNA sequences termed effector binding elements (EBEs).

TAL Effectors with Avirulence Activity in African Strains of Xanthomonas oryzae pv. oryzae.

Background: Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial leaf blight, a devastating disease of rice. Among the type-3 effectors secreted by Xoo to support pathogen virulence, the Transcription Activator-Like Effector (TALE) family plays a critical role.

Confirmation report of Bacterial Leaf Streak disease of rice caused by pv. in Senegal.

pv. (), the causal agent of Bacterial Leaf Streak (BLS), is considered as one of the most important emerging pathogens of rice in Africa. This disease is estimated as responsible of 20 to 30% yield loss (Sileshi et Gebeyehu 2021) and has been characterized in several west African countries including Mali and Burkina Faso since 2003 and more recently in Ivory Coast (Wonni et al.

An atypical class of non-coding small RNAs is produced in rice leaves upon bacterial infection.

Non-coding small RNAs (sRNA) act as mediators of gene silencing and regulate plant growth, development and stress responses. Early insights into plant sRNAs established a role in antiviral defense and they are now extensively studied across plant-microbe interactions. Here, sRNA sequencing discovered a class of sRNA in rice (Oryza sativa) specifically associated with foliar diseases caused by Xanthomonas oryzae bacteria.

RXam2, a NLR from cassava (Manihot esculenta) contributes partially to the quantitative resistance to Xanthomonas phaseoli pv. manihotis.

The overexpression of RXam2, a cassava NLR (nucleotide-binding leucine-rich repeat) gene, by stable transformation and gene expression induction mediated by dTALEs, reduce cassava bacterial blight symptoms. Cassava (Manihot esculenta) is a tropical root crop affected by different pathogens including Xanthomonas phaseoli pv. manihotis (Xpm), the causal agent of cassava bacterial blight (CBB).

First historical genome of a crop bacterial pathogen from herbarium specimen: Insights into citrus canker emergence.

Over the past decade, ancient genomics has been used in the study of various pathogens. In this context, herbarium specimens provide a precious source of dated and preserved DNA material, enabling a better understanding of plant disease emergences and pathogen evolutionary history. We report here the first historical genome of a crop bacterial pathogen, Xanthomonas citri pv.

Cassava diseases caused by Xanthomonas phaseoli pv. manihotis and Xanthomonas cassavae.

Xanthomonas phaseoli pv. manihotis (Xpm) and X. cassavae (Xc) are two bacterial pathogens attacking cassava.

Stop helping pathogens: engineering plant susceptibility genes for durable resistance.

Alternatives to protect crops against diseases are desperately needed to secure world food production and make agriculture more sustainable. Genetic resistance to pathogens utilized so far is mostly based on single dominant resistance genes that mediate specific recognition of invaders and that is often rapidly broken by pathogen variants. Perturbation of plant susceptibility (S) genes offers an alternative providing plants with recessive resistance that is proposed to be more durable.

TAL Effector Repertoires of Strains of pv. in Commercial Cassava Crops Reveal High Diversity at the Country Scale.

Transcription activator-like effectors (TALEs) play a significant role for pathogenesis in several xanthomonad pathosystems. pv. (), the causal agent of Cassava Bacterial Blight (CBB), uses TALEs to manipulate host metabolism.

Repeated gain and loss of a single gene modulates the evolution of vascular plant pathogen lifestyles.

Vascular plant pathogens travel long distances through host veins, leading to life-threatening, systemic infections. In contrast, nonvascular pathogens remain restricted to infection sites, triggering localized symptom development. The contrasting features of vascular and nonvascular diseases suggest distinct etiologies, but the basis for each remains unclear.

The Rice DNA-Binding Protein ZBED Controls Stress Regulators and Maintains Disease Resistance After a Mild Drought.

Background: Identifying new sources of disease resistance and the corresponding underlying resistance mechanisms remains very challenging, particularly in Monocots. Moreover, the modification of most disease resistance pathways made so far is detrimental to tolerance to abiotic stresses such as drought. This is largely due to negative cross-talks between disease resistance and abiotic stress tolerance signaling pathways.

Diagnostic kit for rice blight resistance.

Blight-resistant rice lines are the most effective solution for bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo). Key resistance mechanisms involve SWEET genes as susceptibility factors.

Broad-spectrum resistance to bacterial blight in rice using genome editing.

Bacterial blight of rice is an important disease in Asia and Africa. The pathogen, Xanthomonas oryzae pv. oryzae (Xoo), secretes one or more of six known transcription-activator-like effectors (TALes) that bind specific promoter sequences and induce, at minimum, one of the three host sucrose transporter genes SWEET11, SWEET13 and SWEET14, the expression of which is required for disease susceptibility.

A Plant Pathogen Type III Effector Protein Subverts Translational Regulation to Boost Host Polyamine Levels.

Pathogenic bacteria inject effector proteins into host cells to manipulate cellular processes and facilitate the infection. Transcription-activator-like effectors (TALEs), an effector class in plant pathogenic bacteria, transcriptionally activate host genes to promote disease. We identify arginine decarboxylase (ADC) genes as the host targets of Brg11, a TALE-like effector from the plant pathogen Ralstonia solanacearum.

A Decade Decoded: Spies and Hackers in the History of TAL Effectors Research.

Transcription activator-like effectors (TALEs) from the genus are proteins with the remarkable ability to directly bind the promoters of genes in the plant host to induce their expression, which often helps bacterial colonization. Metaphorically, TALEs act as spies that infiltrate the plant disguised as high-ranking civilians (transcription factors) to trick the plant into activating weak points that allow an invasion. Current knowledge of how TALEs operate allows researchers to predict their activity (counterespionage) and exploit their function, engineering them to do our bidding (a Manchurian agent).

A Pathovar of Infecting Wild Grasses Provides Insight Into the Evolution of Pathogenicity in Rice Agroecosystems.

() are globally important rice pathogens. Virulent lineages from Africa and Asia and less virulent strains from the United States have been well characterized. pv.

Enhancement of vitamin B levels in rice expressing Arabidopsis vitamin B biosynthesis de novo genes.

Vitamin B (pyridoxine) is vital for key metabolic reactions and reported to have antioxidant properties in planta. Therefore, enhancement of vitamin B content has been hypothesized to be a route to improve resistance to biotic and abiotic stresses. Most of the current studies on vitamin B in plants are on eudicot species, with monocots remaining largely unexplored.