Characterization of the small RNA transcriptome in plant-microbe (Brassica/Erwinia) interactions by high-throughput sequencing.

Non-coding, small RNAs (sRNAs) have been identified in a wide spectrum of organisms ranging from bacteria to humans; however, the role and mechanisms of these sRNA in plant immunity is largely unknown. To determine possible roles of sRNA in plant-pathogen interaction, we carried out a high-throughput sRNA sequencing of Brassica campestris using non-infected plants and plants infected with Erwinia carotovora. Consistent with our hypothesis that distinct classes of host sRNAs alerts their expression levels in response to infection, we found that: (1) host 28-nt sRNAs were strongly increased under pathogen infection; and (2) a group of host sRNAs homologous to the pathogen genome also accumulated at significantly higher level.

[Epigenetics of plant vernalization regulated by non-coding RNAs].

Many higher plants must experience a period of winter cold to accomplish the transition from vegetative to reproductive growth. This biological process is called vernalization. Some crops such as wheat (Triticum aestivum L.

A novel method for constructing pathogen-regulated small RNA cDNA library.

Pathogen-responsive endogenous small non-coding RNAs regulate gene expression in relation to plant immune responses by serving as RNA silencing machinery. Decay caused by the bacterium, Erwinia carotovora subsp. carotovora (Ecc), often leads to soft rot disease in the plant Brassica campestris L.

A multidrug resistance transporter in Magnaporthe is required for host penetration and for survival during oxidative stress.

In prokaryotes and eukaryotes, multidrug resistance (MDR) transporters use energy-dependent efflux action to regulate the intracellular levels of antibiotic or xenobiotic compounds. Using mutational analysis of ABC3, we define an important role for such MDR-based efflux during the host penetration step of Magnaporthe grisea pathogenesis. Mutants lacking ABC3 were completely nonpathogenic but were surprisingly capable of penetrating thin cellophane membranes to some extent.