Stop helping pathogens: engineering plant susceptibility genes for durable resistance

Alternatives to protect crops against diseases are desperately needed to secure world food production and make agriculture more sustainable. Genetic resistance to pathogens utilized so far is mostly based on single dominant resistance genes that mediate specific recognition of invaders and that is often rapidly broken by pathogen variants. Perturbation of plant susceptibility (S) genes offers an alternative providing plants with recessive resistance that is proposed to be more durable. S genes enable the establishment of plant disease, and their inactivation provides opportunities for resistance breeding of crops. However, loss of S gene function can have pleiotropic effects. Developments in genome editing technology promise to provide powerful methods to precisely interfere with crop S gene functions and reduce tradeoffs

A high finesse bow-tie cavity for strong atom-photon coupling in Rydberg arrays

We report a high-finesse bow-tie cavity designed for atomic physics experiments with Rydberg atom arrays. The cavity has a finesse of $51,000$ and a waist of $7.1$ $\mu$m at the cesium D2 line ($852$ nm). With these parameters, the cavity induces strong coupling between a single atom and a single photon, corresponding to a cooperativity per traveling mode of $35$ at the cavity waist. To trap and image atoms, the cavity setup utilizes two in-vacuum aspheric lenses with numerical aperture (N.A.) $0.35$ and is capable of housing N.A. $0.5$ microscope objectives. In addition, the large atom-mirror distance ($\gtrsim1.5$ cm) provides good optical access and minimizes stray electric fields at the position of the atoms. This cavity setup can operate in tandem with the Rydberg array platform, creating a fully connected system for quantum simulation and computation

In planta gene expression analysis of Xanthomonas oryzae pathovar oryzae, African strain MAI1

<p>Abstract</p> <p>Background</p> <p>Bacterial leaf blight causes significant yield losses in rice crops throughout Asia and Africa. Although both the Asian and African strains of the pathogen, <it>Xanthomonas oryzae </it>pv. <it>oryzae </it>(<it>Xoo</it>), induce similar symptoms, they are nevertheless genetically different, with the African strains being more closely related to the Asian <it>X. oryzae </it>pv. <it>oryzicola </it>(<it>Xoc</it>).</p> <p>Results</p> <p>Changes in gene expression of the African <it>Xoo </it>strain MAI1 in the susceptible rice cultivar Nipponbare were profiled, using an SSH <it>Xoo </it>DNA microarray. Microarray hybridization was performed comparing bacteria recovered from plant tissues at 1, 3, and 6 days after inoculation (dai) with bacteria grown <it>in vitro</it>. A total of 710 bacterial genes were found to be differentially expressed, with 407 up-regulated and 303 down-regulated. Expression profiling indicated that less than 20% of the 710 bacterial transcripts were induced in the first 24 h after inoculation, whereas 63% were differentially expressed at 6 dai. The 710 differentially expressed genes were one-end sequenced. 535 sequences were obtained from which 147 non-redundant sequences were identified. Differentially expressed genes were related to metabolism, secretion and transport, pathogen adherence to plant tissues, plant cell-wall degradation, IS elements, and virulence. In addition, various other genes encoding proteins with unknown function or showing no similarity to other proteins were also induced. The <it>Xoo </it>MAI1 non-redundant set of sequences was compared against several <it>X. oryzae </it>genomes, revealing a specific group of genes that was present only in MAI1. Numerous IS elements were also found to be differentially expressed. Quantitative real-time PCR confirmed 86% of the identified profile on a set of 14 genes selected according to the microarray analysis.</p> <p>Conclusions</p> <p>This is the first report to compare the expression of <it>Xoo </it>genes <it>in planta </it>across different time points during infection. This work shows that as-yet-unidentified and potentially new virulence factors are appearing in an emerging African pathogen. It also confirms that African <it>Xoo </it>strains do differ from their Asian counterparts, even at the transcriptional level.</p

Stop helping pathogens: engineering plant susceptibility genes for durable resistance

Alternatives to protect crops against diseases are desperately needed to secure world food production and make agriculture more sustainable. Genetic resistance to pathogens utilized so far is mostly based on single dominant resistance genes that mediate specific recognition of invaders and that is often rapidly broken by pathogen variants. Perturbation of plant susceptibility (S) genes offers an alternative providing plants with recessive resistance that is proposed to be more durable. S genes enable the establishment of plant disease, and their inactivation provides opportunities for resistance breeding of crops. However, loss of S gene function can have pleiotropic effects. Developments in genome editing technology promise to provide powerful methods to precisely interfere with crop S gene functions and reduce tradeoffs

First report of Cassava Bacterial Blight caused by Xanthomonas axonopodis pv. manihotis in Burkina Faso

International audienc