Meeting report: GARNet/OpenPlant CRISPR-Cas workshop

Targeted genome engineering has been described as a "game-changing technology" for fields as diverse as human genetics and plant biotechnology. One technique used for precise gene editing utilises the CRISPR-Cas system and is an effective method for genetic engineering in a wide variety of plants. However, many researchers remain unaware of both the technical challenges that emerge when using this technique or of its potential benefits. Therefore in September 2015, GARNet and OpenPlant organized a two-day workshop at the John Innes Centre that provided both background information and hands-on training for this important technology.

The plant nuclear envelope and regulation of gene expression

The nuclear envelope (NE) separates the key mechanisms of transcription and translation, and as such is a critical control point in all eukaryotic cells. In plants, the proteins of the NE influence a number of processes including the control of nucleo-cytoplasmic transport of RNA and protein, chromatin localization to the nuclear periphery, and direct chromatin binding by members of the nuclear pore complex (NPC). In this review I attempt to bring these roles under the umbrella of their effect on gene expression, even though the complex nature of this cellular environment means there is considerable overlap of effects. Although the volume of research in plant cells has greatly improved over recent years, it is clear that our understanding of how the components of the NE either directly or indirectly influence gene expression is still in its infancy.

Effect of plasticity and atmospheric pressure on the formation of donut- and croissantlike buckles

The formation of donut- and croissantlike buckles has been observed onto the free surface of gold thin films deposited on silicon substrates. Numerical simulations clearly evidence that the coupling effect between the atmospheric pressure acting on the free surface and the plastic folding of the ductile film is responsible for the circular blister destabilization and the formation of the donut- and croissantlike buckling patterns.

Overexpressing components of the nuclear transport apparatus causes severe growth symptoms in tobacco leaves

Regulating nucleo-cytoplasmic transport of RNA and protein is a key cellular control point. Perturbing the function of plant nuclear transport components can cause significant developmental defects and in this report we add an important line to this evidence. Overexpression of AtRAN1 or AtNUP62 in Nicotiana benthamiana causes significant damage to leaf tissue. This demonstrates that the precise control of nuclear transport is an important aspect of maintaining tissue integrity.

Components of the Arabidopsis nuclear pore complex play multiple diverse roles in control of plant growth

The nuclear pore complex (NPC) is a multisubunit protein conglomerate that facilitates movement of RNA and protein between the nucleus and cytoplasm. Relatively little is known regarding the influence of the Arabidopsis NPC on growth and development. Seedling development, flowering time, nuclear morphology, mRNA accumulation, and gene expression changes in Arabidopsis nucleoporin mutants were investigated. Nuclear export of mRNA is differentially affected in plants with defects in nucleoporins that lie in different NPC subcomplexes. This study reveals differences in the manner by which nucleoporins alter molecular and plant growth phenotypes, suggesting that nuclear pore subcomplexes play distinct roles in nuclear transport and reveal a possible feedback relationship between the expression of genes involved in nuclear transport.

Assessing the function of the plant nuclear pore complex and the search for specificity

Plant cells encounter a wide variety of molecules that influence their gene expression and development. A key component of most signal transduction pathways involves the regulated movement of molecules into and out of the nucleus. The plant nuclear pore complex (NPC) is a critical controlling element in this nucleocytoplasmic movement of protein and RNA. The NPC is comprised of approximately 30 nucleoporin proteins arranged in radial symmetry around the central pore. Over recent years our understanding of how the NPC impacts different signalling pathways has increased following the identification of a range of nucleoporin mutant plants. These mutants allow us to gain insight into how the response to hormonal, abiotic, and biotic stresses are effected by changes in nuclear transport. Importantly we have little information regarding the specific molecules whose nuclear transport is altered in these processes and the identification of these proteins is a significant challenge. Here is presented an overview as to how the members of the plant NPC affect signalling pathways, highlighting the progress and difficulties within this research area.