This chapter describes methods for targeted knockouts using marker exchange mutagenesis and complementation of the Gram-negative bacteria Xanthomonas oryzae pv. oryzae. We have used these methods to demonstrate that type I secretion and modification systems are involved in avrXa21 activity of X. oryzae pv. oryzae.

Common bacterial blight is a devastating seed-borne disease of common beans that also occurs on other legume species including lablab and Lima beans. We sequenced and analyzed the genomes of 26 strains of Xanthomonas axonopodis pv. phaseoli and X. fuscans subsp. fuscans, the causative agents of this disease, collected over four decades and six continents. This revealed considerable genetic vari...

SUMMARY Xanthomonas oryzae pv. oryzae and Xanthomonas oryzae pv. oryzicola cause bacterial blight and bacterial leaf streak of rice (Oryza sativa), which constrain production of this staple crop in much of Asia and parts of Africa. Tremendous progress has been made in characterizing the diseases and breeding for resistance. X. oryzae pv. oryzae causes bacterial blight by invading the vascular t...

Comparison of the DNA sequences and genes of two genomes can be useful to investigate the common functionalities of the corresponding organisms and get a better understanding of how the genes or groups of genes are organized and involved in several functions. In this paper we use high-performance parallel computing to compare the whole genomes of two organisms, namely Xanthomonas axonopodis pv....

Disruption of ppsA, a key gene in gluconeogenesis, of Xanthomonas campestris pv. campestris resulted in the failure of the pathogen to grow in medium with pyruvate or C4-dicarboxylates as the sole carbon source and a significant reduction in virulence, indicating that X. campestris pv. campestris possesses only the malic enzyme-PpsA route in gluconeogenesis, which is required for virulence.

Xanthomonas axonopodis pv manihotis (Xam) is the causal agent of cassava bacterial blight (CBB) worldwide. To develop a well-organized disease management policy in a country, the diversity of pathogens population must be known. The bacterial populations of Xanthomonas axonopodis pv manihotis (Xam) obtained as flora cassava leaves and stems, in Nigeria were characterized by their biochemical and...

The taxonomy and evolutionary relationships among members of the genus Xanthomonas associated with tomato and pepper have been a matter of considerable controversy since their original description in 1921. These bacteria, which are a major affliction of tomato and pepper crops in warm and humid regions, were originally described as a single species, but subsequent research has shown the existen...