Xanthomonas campestris strains have been reported to undergo programmed cell death (PCD) in a protein rich medium. Protein hydrolysates used in media such as nutrient broth comprise of casein digest with abundance of proline and glutamate. In the current study, X. campestris pv. campestris (Xcc) cells displayed PCD when grown in PCD inducing medium (PIM) containing casein tryptic digest. This P...

We have devised a rapid four-step procedure for the generation of directed and unmarked chromosomal deletions in bacteria, based on the use of a novel cloning vector containing the Bacillus subtilis sacB gene that encodes levansucrase and confers sucrose sensitivity, which can be used for counter-selection. Using this technique, we describe the construction of a 6.5 kb directed and unmarked del...

Xanthomonas campestris JX, a soil bacterium, is an industrially productive strain for xanthan gum. Here we present a 5.0-Mb assembly of its genome sequence. We have annotated 12 coding sequences (CDSs) responsible for xanthan gum biosynthesis, 346 CDSs encoding carbohydrate metabolism, and 69 CDSs related to virulence, defense, and plant disease.

We describe useful vectors to select double-crossover events directly in site-directed marker exchange mutagenesis in gram-negative bacteria. These vectors contain the gusA marker gene, providing colorimetric screens to identify bacteria harboring those sequences. The applicability of these vectors was shown by mapping the 3' end of the Xanthomonas campestris gum operon, involved in biosynthesi...

Seeds are involved in the vertical transmission of microorganisms from one plant generation to another and consequently act as reservoirs for the plant microbiota. However, little is known about the structure of seed-associated microbial assemblages and the regulators of assemblage structure. In this work, we have assessed the response of seed-associated microbial assemblages of Raphanus sativu...

Computational analyses of four bacterial genomes of the Xanthomonadaceae family reveal new unique genes that may be involved in adaptation, pathogenicity, and host specificity. The Xanthomonas genus presents 3636 unique genes distributed in 1470 families, while Xylella genus presents 1026 unique genes distributed in 375 families. Among Xanthomonas-specific genes, we highlight a large number of ...

Banana Xanthomonas wilt is a newly emerging disease that is currently threatening the livelihoods of millions of farmers in East Africa. The causative agent is Xanthomonas campestris pathovar musacearum (Xcm), but previous work suggests that this pathogen is much more closely related to species Xanthomonas vasicola than to X. campestris. We have generated draft genome sequences for a banana-pat...

Ralstonia solanacearum GMI1000 is a gram-negative plant pathogen which contains an hrp gene cluster which codes for a type III protein secretion system (TTSS). We identified two novel Hrp-secreted proteins, called PopF1 and PopF2, which display similarity to one another and to putative TTSS translocators, HrpF and NopX, from Xanthomonas spp. and rhizobia, respectively. They also show similariti...

AvrBsT is a type III effector from Xanthomonas campestris pv vesicatoria that is translocated into plant cells during infection. AvrBsT is predicted to encode a Cys protease that targets intracellular host proteins. To dissect AvrBsT function and recognition in Arabidopsis thaliana, 71 ecotypes were screened to identify lines that elicit an AvrBsT-dependent hypersensitive response (HR) after Xa...

ABSTRACT Xanthomonas campestris pv. campestris (X. campestris) infects a large number of cruciferous plants, including weeds. California has one of the largest and most diverse populations of wild cruciferous plants in the world. Although considerable information is available on the genetic diversity of X. campestris in commercial crop plants, nothing is known about the diversity in strains inf...