Ideal plant architecture1 (IPA1) is critical in regulating rice (Oryza sativa) plant architecture and substantially enhances grain yield. To elucidate its molecular basis, we first confirmed IPA1 as a functional transcription activator and then identified 1067 and 2185 genes associated with IPA1 binding sites in shoot apices and young panicles, respectively, through chromatin immunoprecipitatio...

ABSTRACT The crown gall pathosystem was used to evaluate a model that describes the dose-response relationship between biological control agents and plant pathogens. The model predicts that this relationship can become asymptotic, such that increased antagonist doses cannot compensate for deficiencies in disease suppression. Wounded roots of tomato (Lycopersicon esculentum) and cherry (Prunus m...

Gall inducing insects most frequently oviposit in young tissues because these tissues have higher metabolism and potential for differentiation. However, these insects may also successfully establish in mature tissues as was observed in the super-host Copaifera langsdorffii. Among C. langsdorffii gall morphotypes, one of the most common is a midrib gall induced by an undescribed species of Cecid...

Reactive oxygen species (ROS) play a major role in plant defense against pathogens, but evidence for their role in defense against insects is still preliminary and inconsistent. In this study, we examined the potential role of ROS in defense of wheat (Triticum aestivum) and rice (Oryza sativa) against Hessian fly (Mayetiola destructor) larvae. Rapid and prolonged accumulation of hydrogen peroxi...

The bacterium Agrobacterium tumefaciens causes crown gall tumor formation in plants. During infection the bacteria translocate an oncogenic piece of DNA (transferred DNA, T-DNA) into plant cells at the infection site. A number of virulence proteins are cotransported into host cells concomitantly with the T-DNA to effectuate transformation. Using yeast as a model host, we find that one of these ...

By using a binary vector system, we examined the requirements for border sequences in T-DNA transformation of plant genomes. Mini-T plasmids consisting of small replicons with different extents of pTiT37 T-DNA were tested for plant tumor-inducing ability in Agrobacterium tumefaciens strain LBA4404 containing helper plasmid pAL4404 (which encodes virulence genes needed for T-DNA transfer). Assay...

The Ti plasmid sequences (T-DNA) from the octopine-producing crown gall tumor A6S/2 were isolated by molecular cloning, using the bacteriophage lambda vector Charon 4A. Analysis of the cloned DNA segments indicates that the Ti plasmid sequences are covalently joined to plant nuclear DNA. These data demonstrate that genetic recombination between a eukaryote and a prokaryote can occur as a natura...

Many hypotheses have been proposed to explain the diversity of gall-midge insects (Diptera: Cecidomyiidae), some of them taking into account plant diversity. This study aims to test the importance of size, age and composition of host plant taxa in the diversity of Cecidomyiidae. For this we used inventories data on the diversity of galling and host plants in Brazil. We found that Asterales, Myr...

Nonchemical methods and strategies for nematode management including cultural methods and engineered measures have been recommended as an alternative to methyl bromide (a major soil fumigant), due to its role in the depletion of the ozone layer. Hence, an international agreement has recently been reached calling for its reduced consumption and complete phasing out. This present research evaluat...

Plant populations frequently maintain submaximal levels of resistance to natural enemies, even in the presence of substantial genetic variation for resistance. Identifying constraints on the evolution of increased resistance has been a major goal of researchers of plant-herbivore interactions. In a glasshouse study, we measured relative costs and benefits of resistance of tall goldenrod (Solida...