Jianchi Chen

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Xylella fastidiosa is a Gram-negative plant-pathogenic bacterium causing many economically important diseases, including almond leaf scorch disease (ALSD) in California. Genome information greatly facilitates research on this nutritionally fastidious organism. Here we report the complete genome sequences of two ALSD strains of this bacterium, M12 and M23.
Xylella fastidiosa causes diseases on a growing list of economically important plants. An understanding of how xylellae diseases originated and evolved is important for disease prevention and management. In this study, we evaluated the phylogenetic relationships of X. fastidiosa strains from citrus, grapevine, and mulberry through the analyses of random(More)
Little is known about specific host chemistry effects on zebra chip disease symptom development in potatoes (Solanum tuberosum). This research compared chemical profiles and defense-related enzyme levels between non-symptomatic and zebra chip-symptomatic potato tubers. Levels of phenolics, five amino acids, peroxidases, polyphenol oxidases, chitinases, and(More)
In the past years we have witnessed an explosive growth of the data and information on the World Wide Web, which makes it difficult for normal users to find the information that they are interested in. On the other hand, the majority of the data and resources are very unpopular, which can be considered as “hidden information”, and are very difficult to(More)
Pierce's disease of grapevine (PD), caused by the bacterial pathogen Xylella fastidiosa, remains a serious problem for grape production in California and elsewhere. This research examined induction of phenolic compounds in grapevines ('Thompson Seedless') infected with X. fastidiosa over a 6-month period. Two months postinoculation with X. fastidiosa,(More)
The xylem-limited bacterium Xylella fastidiosa (Xf) causes Pierce's disease (PD), an important disease of grapevine, Vitis vinifera L. Grapevine rootstocks were developed to provide increased resistance to root disease, but rootstock effects on cane and vine diseases remain unclear. Grapevines that consisted of Cabernet Sauvignon or Chardonnay grafted to 13(More)
Long-term sustainable management of zebra chip (ZC) disease of potato requires development of tolerant or resistant germplasm. To this end, 283 potato varieties and breeding clones were infected with the ZC putative causal agent 'Candidatus Liberibacter solanacearum' (Lso) by potato psyllid vector inoculations in 2010, 2011, 2012, and 2013. Potato germplasm(More)
Pierce's disease (PD, Xylella fastidiosa) of grapevine is the primary pathogen limiting vinifera grape production in Florida and other regions of the southeastern United States. Quick and accurate detection of PD strains is essential for PD studies and control. A unique random amplified polymorphic DNA (PD1-1-2) was isolated from a PD strain from Florida.(More)
The nucleotide sequences of 16S rDNAs (coding for the small subunit ribosomal RNAs) were used to identify Xylella fastidiosa, a nutritionally fastidious plant pathogenic bacterium. The near-complete 16S rDNAs from nine strains of Xyl. fastidiosa, including seven pathotypes and one strain of Xanthomonas campestris pv. campestris, were amplified through PCR(More)
The bacterium 'Candidatus Liberibacter solanacearum' is associated with zebra chip disease (ZC), a threat to potato production in North America and New Zealand. It is vectored by potato psyllids. Previous studies observed that 'Ca. L. solanacearum' infection causes potato tubers to undergo ZC-symptom-associated shifts in physiology, such as increased levels(More)