MEICOM was designed to achieve a better understanding of the factors that influence the transitions from DNA double strand breaks (DSBs) formation to meiotic crossovers (COs) in crops and evaluate the most effective methodologies to manipulate this outcome. Crop breeding is necessary to deliver Food Security in the near future, factors such as population growth, urban and industrial development, mass migration and climate change would require a sustained improvement in food production, storage and distribution globally. Crop breeding has a very important role to play in provide these improvements. Crop breeding methods rely on meiotic recombination to generate genetic variation through the formation of COs to produce plants with new genetic combinations to provide new improved crop varieties ready to withstand our changing environment challenges of the future. Nevertheless, meiotic recombination has natural major limitations that plant breeders need to overcome. The main ones are that CO frequency is limited in number (1-3 COs per chromosome pair) and CO localization is restricted to some chromosome regions (with up to 70% of the physical length of individual chromosomes rarely recombining in cereals). If we are able to determine the different factors that regulate CO frequency and localization in crops and evaluate different strategies to manipulate this regulation, we would be able to provide plant breeders with new tools and methodologies to improve crop breeding in the new decades.
To achieve this ambitious goal we assembled a network of leading European plant meiosis research groups (MEICOM) with a wide range of complementary research skills and excellent track record of synergistic interactions. The training also has benefited from close involvement of stakeholder breeding companies who have provided first-hand insight into the major challenges that confront the industry. Importantly, MEICOM has provided a major contribution to ensuring a critical mass of highly trained early career scientists with skills that will be required to tackle the global challenge of Food Security. The overall objectives were: to understand the influence of the genomic environment on crossover formation/control in crops and evaluate how it can be modified to adjust the crossover/non-crossover outcome, to study how meiotic progression in large genome crops is integrated with, and influences the crossover/non-crossover repair fate of DNA double-strand breaks, and to develop and implement novel strategies for modifying crossover patterning in target crops. Results have been very important to realize the differences in the control of meiotic recombination among the different crop species (and specially the model plant Arabidopsis thaliana). Another important result is the possibility of Genome-wide high-throughput pollen genotyping in cereals and the chance to be applied to other crops. Different groups in the network have set up different methods to apply chemicals to gonads which can manipulate the outcomes of meiosis in different crops (e.g.: barley, tomato, brassicas).
