Regulatory approaches for genome edited agricultural plants in select countries and jurisdictions around the world.

Genome editing in agriculture and food is leading to new, improved crops and other products. Depending on the regulatory approach taken in each country or region, commercialization of these crops and products may or may not require approval from the respective regulatory authorities. This paper describes the regulatory landscape governing genome edited agriculture and food products in a selection of countries and regions.

Removing politics from innovations that improve food security.

Genetically modified (GM) organisms and crops have been a feature of food production for over 30 years. Despite extensive science-based risk assessment, the public and many politicians remain concerned with the genetic manipulation of crops, particularly food crops. Many governments have addressed public concern through biosafety legislation and regulatory frameworks that identify and regulate risks to ensure human health and environmental safety. These domestic regulatory frameworks align to international scientific risk assessment methodologies on a case-by-case basis. Regulatory agencies in 70 countries around the world have conducted in excess of 4400 risk assessments, all reaching the same conclusion: GM crops and foods that have been assessed provide no greater risk to human health or the environment than non-GM crops and foods. Yet, while the science regarding the safety of GM crops and food appears conclusive and societal benefits have been globally demonstrated, the use of innovative products have only contributed minimal improvements to global food security. Regrettably, politically-motivated regulatory barriers are currently being implemented with the next genomic innovation, genome editing, the implications of which are also discussed in this article. A decade of reduced global food insecurity was witnessed from 2005 to 2015, but regrettably, the figure has subsequently risen. Why is this the case? Reasons have been attributed to climate variability, biotic and abiotic stresses, lack of access to innovative technologies and political interference in decision making processes. This commentary highlights how political interference in the regulatory approval process of GM crops is adversely affecting the adoption of innovative, yield enhancing crop varieties, thereby limiting food security opportunities in food insecure economies.

Functional significance of dauciform roots: exudation of carboxylates and acid phosphatase under phosphorus deficiency in Caustis blakei (Cyperaceae).

Caustis blakei produces an intriguing morphological adaptation by inducing dauciform roots in response to phosphorus (P) deficiency. We tested the hypothesis that these hairy, swollen lateral roots play a similar role to cluster roots in the exudation of organic chelators and ectoenzymes known to aid the chemical mobilization of sparingly available soil nutrients, such as P. Dauciform-root development and exudate composition (carboxylates and acid phosphatase activity) were analysed in C. blakei plants grown in nutrient solution under P-starved conditions. The distribution of dauciform roots in the field was determined in relation to soil profile depth and matrix. The percentage of dauciform roots of the entire root mass was greatest at the lowest P concentration ([P]) in solution, and was suppressed with increasing solution [P], while in the field dauciform roots were predominantely located in the upper soil horizons, and decreased with increasing soil depth. Citrate was the major carboxylate released in an exudative burst from mature dauciform roots, which also produced elevated levels of acid phosphatase activity. Malonate was the dominant internal carboxylate present, with the highest concentration in young dauciform roots. The high concentration of carboxylates and phosphatases released from dauciform roots, combined with their prolific distribution in the organic surface layer of nutrient-impoverished soils, provides an ecophysiological advantage for enhancing nutrient acquisition.

Cytokinin-induced abnormal shoot organogenesis is associated with elevated Knotted1-type homeobox gene expression in tobacco.

The molecular mechanisms that regulate the transcription of key developmental genes involved in shoot organogenesis have yet to be fully elucidated. However, it is clear that plant growth regulators, such as cytokinin, play a critical role in the differentiation of adventitious shoots. In Nicotiana tabacum zz100 leaf discs, high frequency shoot formation could be induced with 5 microM of the cytokinin N6-benzyladenine (BA). Increasing the exogenous BA concentration to greater than 20 microM resulted in stunted explants with abnormal shoot morphology and altered mineral composition. Explants with abnormal shoots did not appear to be hyperhydric. Abnormalities were, however, associated with an increase in the expression of a knotted1-type homeobox gene (TobH1) isolated from normal shoot-forming cultures. The results suggest that the development of cytokinin-induced abnormal shoot morphology possibly involves changes in TobH1 gene expression.

Inorganic nitrogen requirements during shoot organogenesis in tobacco leaf discs.

The role of nitrate, ammonium, and culture medium pH on shoot organogenesis in Nicotiana tabacum zz100 leaf discs was examined. The nitrogen composition of a basal liquid shoot induction medium (SIM) containing 39.4 mM and 20.6 mM was altered whilst maintaining the overall ionic balance with Na(+) and Cl(-) ions. Omission of total nitrogen and nitrate, but not ammonium, from SIM prevented the initiation and formation of shoots. When nitrate was used as the sole source of nitrogen, a high frequency of explants initiated and produced leafy shoots. However, the numbers of shoots produced were significantly fewer than the control SIM. Buffering nitrate-only media with the organic acid 2[N-morpholino]ethanesulphonic acid (MES) could not compensate for the omission of ammonium. Ammonium used as the sole source of nitrogen appeared to have a negative effect on explant growth and morphogenesis, with a significant lowering of media pH. Buffering ammonium-only media with MES stabilized pH and allowed a low frequency of explants to initiate shoot meristems. However, no further differentiation into leafy shoots was observed. The amount of available nitrogen appears to be less important than the ratio between nitrate and ammonium. Shoot formation was achieved with a wide range of ratios, but media containing 40 mM nitrate and 20 mM ammonium (70:30) produced the greatest number of shoots per explant. Results from this study indicate a synergistic effect between ammonium and nitrate on shoot organogenesis independent of culture medium pH.