Vishnu Narayanan Madhavan

University of Southern Denmark | SDU · Department of Biochemistry and Molecular Biology

Historically, Xanthomonas species are primarily known for their pathogenicity against plants, but recently, there have been more findings of non-pathogenic xanthomonads. In the present study, we report isolates from healthy rice seeds that belong to a new species, X. protegens, a protector of the rice plants against a serious pathogenic counterpart...

Xanthomonas species are major pathogens of plants and have been studied extensively. There is increasing recognition of the importance of non-pathogenic species within the same genus. With this came the need to understand the genomic and functional diversity of non-pathogenic Xanthomonas (NPX) at the species and strain level. This study reports iso...

Rice seed microbiota play a vital role throughout their growth and developmental stages. Xanthomonas sontii is known as an abundant, core-vertically transmitted rice seed endophyte with probiotic properties. Studies reveal a less explored world of non-pathogenic Xanthomonas (NPX) species like X. sontii and X. indica that are associated with healthy...

Bacteria respond to environmental cues in different ways. Phase variation is one such adaptation where heritable and reversible changes in DNA aid bacteria to alter the expression of specific genes. The bacterial plant pathogen Xanthomonas oryzae pv. oryzae (Xoo) causes the serious bacterial blight disease of rice. The mucoid phenotype of Xoo colon...

Xanthomonas species have been extensively studied as major and model pathogens of plants. However, there is an increasing recognition of the complex and large world of non-pathogenic species of Xanthomonas in recent decades. One pathogenic Xanthomonas species has been known in rice for the last hundred years, yet in recent years, three non-pathogen...

Xanthomonas is a major group of pathogenic bacteria infecting staple food crops like rice. Increasingly it is being recognized that non-pathogenic Xanthomonas (NPX) are also important members of a healthy plant microbiome. However, the vast majority of the species described in this genus are of pathogenic nature, and only a few NPX species have bee...

Two yellow pigmented bacterial strains were isolated from healthy rice seeds. The strains designated as PPL560 T and PPL568 were identified as members of genus Xanthomonas based on analysis of biochemical and 16S rRNA gene sequence retrieved from whole genome sequence. Isolates formed a distinct monophyletic lineage with X. sontii and X. sacchari a...

The plant immune system has evolved to resist attack by pathogens and pests. However, successful phytopathogens deliver effector proteins into plant cells where they hijack the host cellular machinery to suppress the plant immune responses and promote infection. This manipulation of the host cellular pathways is done by the pathogen using various e...

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 rema...

Figure S1. Evolutionary relationship between vascular pathogenesis and a conserved cell wall-degrading enzyme in Xanthomonas bacteria. Figure S2. Vascular, xylem pathogenesis strongly correlates with presence of cbsA but not host species. Figure S3. The evolution and genomic context of cbsA. Figure S4. Specific inactivation events for cbsA homol...

Figure S8. Mid-point rooted, nucleotide-based maximum likelihood phylogenies of all genes in the type 3 cbsA neighborhood, with midpoint rooting. Bootstrap support values (out of 100) are indicated above each bipartition. Each tip of the tree lists the full name of the isolate from which the sequence was retrieved in addition to the sequence’s acce...

Figure S7. Mid-point rooted, nucleotide-based maximum likelihood phylogenies of all genes in the type 4 cbsA neighbourhood. Bootstrap support values (out of 100) are indicated above each bipartition. Each tip of the tree lists the full name of the isolate from which the sequence was retrieved in addition to the sequence’s accession number. Tree tip...

Table S1: Metadata of all genomes included in this study. Table S2: Metadata and BayesTraits scores of orthogroups. Table S3: All genomic neighborhoods identified in this study. Table S4: Topology tests for cbsA and flanking genes to test hypothesis of horizontal gene transfer from X. phaseoli clade to X. campestris. Table S5: Topology tests for cb...

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