Cloning of the Cytochrome Gene From the Tomato Powdery Mildew Fungus Reveals High Levels of Allelic Variation and Heteroplasmy for the G143A Mutation.

is a major pathogen of tomato and several other crops that can cause substantial yield losses in favorable conditions for the fungus. Quinone outside inhibitor fungicides (QIs) are routinely used for the control of the pathogen in tomato fields across California, but their recurrent use could lead to the emergence of resistance against these compounds. Here, we partially cloned the cytochrome gene from () and searched within populations of the fungus collected from tomato fields across California for mutations that confer resistance to QIs.

Comparative Genomics of the Sigatoka Disease Complex on Banana Suggests a Link between Parallel Evolutionary Changes in Pseudocercospora fijiensis and Pseudocercospora eumusae and Increased Virulence on the Banana Host.

The Sigatoka disease complex, caused by the closely-related Dothideomycete fungi Pseudocercospora musae (yellow sigatoka), Pseudocercospora eumusae (eumusae leaf spot), and Pseudocercospora fijiensis (black sigatoka), is currently the most devastating disease on banana worldwide. The three species emerged on bananas from a recent common ancestor and show clear differences in virulence, with P. eumusae and P.

Structural Analysis of an Avr4 Effector Ortholog Offers Insight into Chitin Binding and Recognition by the Cf-4 Receptor.

Chitin is a key component of fungal cell walls and a potent inducer of innate immune responses. Consequently, fungi may secrete chitin-binding lectins, such as the Cf-Avr4 effector protein from the tomato pathogen Cladosporium fulvum, to shield chitin from host-derived chitinases during infection. Homologs of Cf-Avr4 are found throughout Dothideomycetes, and despite their modest primary sequence identity, many are perceived by the cognate tomato immune receptor Cf-4.

Effects of manure-application practices on curli production by Escherichia coli transported through soil.

The release of Escherichia coli into the environment from untreated manure can pose a threat to human health. Environmental survival of E. coli has been linked to extracellular fibers called curli.

Colloid transport and retention in unsaturated porous media: effect of colloid input concentration.

Colloids play an important role in facilitating transport of adsorbed contaminants in soils. Recent studies showed that under saturated conditions colloid retention was a function of its concentration. It is unknown if this is the case under unsaturated conditions.