Establishment of regeneration and transformation protocols to create hypoalleregenic peanut (Arachis hypogaea) and mustard (Brassica juncea) through genome editing

A stable and reproducible in vitro regeneration system is necessary for genetic engineering, however, explant responses vary widely between and within species and are highly dependent on the culture conditions. Despite decades of research, plant regeneration is still challenging especially with some plant species referred to as recalcitrant. In this study, we investigated the regeneration and genetic transformation capacities of different lines of peanut (Arachis hypogaea) that is considered recalcitrant and Brown mustard (Brassica juncea) in order to enable editing of the allergens Ara h 1 and Bra J I in peanut and mustard, respectively, via CRISPR/Cas9. Moreover, we demonstrated that, several of the first edited mustard lines displayed reduced or total absence of the Bra J I protein. Firstly, the factors affecting the adventitious shoot regeneration of both plant species were investigated using four peanut lines and six mustard lines from two geographical regions (Europe and India). In both species, shoot regeneration was significantly influenced by the explant type and the genetic make-up of the different lines tested. In mustard, the 5 days old cotyledon explants of all lines showed better responses than hypocotyls regarding adventitious shoot regeneration whereas in peanut the leaflet explants of 5-day-old seedlings exhibited superiority. The combinations of different types of cytokinins and auxins were tested on the explants of both plant species. In all peanut lines, the leaflet explants responded best on medium with 22.19 µM 6-benzylaminopurine (BAP) (+ 2.3 µM kinetin), which was reduced to 7.40 µM BAP after eight weeks, with regeneration rates of 10-89.1% and a mean shoot number per regenerating explant of 1-3.1 shoots. For mustard, the medium containing 8.88 µM BAP, 5.37 µM 1-naphthaleneacetic acid (NAA), and 9.95 µM Silver nitrate (AgNO3) resulted in the highest shoot regeneration rates (58-72% and 65-90% for the European and Indian lines, respectively) as well as the highest shoot numbers per regenerating explant (2.2-2.7 and 2.3-3.0). Furthermore, the effect of different light qualities on shoot regeneration from leaflet explants of the peanut lines was investigated in order to promote shoot induction and elongation. A strong effect of the culture temperature on the regeneration efficiency was observed as different light treatments were connected with different culture temperatures. However, red and blue LEDs could substitute tubular fluorescent lamps without affecting shoot regeneration. In the second step, Agrobacterium-mediated transformation of both plant species was investigated. Transgenic plants carrying large deletions of 566 up to 790 bp as well as indels in the targeted regions especially, indels in all four Bra j I alleles were obtained with the mustard lines tested. Seed viability was investigated in several transgenic mustard lines through in vitro and ex vitro germination. A decrease in seed viability and seed formation was observed in some edited lines, which indicated that the mutation of the major allergen Bra J I in mustard affected seed development. Part of the seeds exhibited aberrant phenotypes that resulted in the rupture of the testa already in the siliques. In contrast, the regenerated shoots from the different transformation experiments with various peanut lines exhibited a lack of transgenicity

Redesigning crop varieties to win the race between climate change and food security

Climate change poses daunting challenges to agricultural production and food security. Rising temperatures, shifting weather patterns, and more frequent extreme events have already demonstrated their effects on local, regional, and global agricultural systems. Crop varieties that withstand climate-related stresses and are suitable for cultivation in innovative cropping systems will be crucial to maximize risk avoidance, productivity, and profitability under climate-changed environments. We surveyed 588 expert stakeholders to predict current and novel traits that may be essential for future pearl millet, sorghum, maize, groundnut, cowpea, and common bean varieties, particularly in sub-Saharan Africa. We then review the current progress and prospects for breeding three prioritized future-essential traits for each of these crops. Experts predict that most current breeding priorities will remain important, but that rates of genetic gain must increase to keep pace with climate challenges and consumer demands. Importantly, the predicted future-essential traits include innovative breeding targets that must also be prioritized; for example, (1) optimized rhizosphere microbiome, with benefits for P, N, and water use efficiency, (2) optimized performance across or in specific cropping systems, (3) lower nighttime respiration, (4) improved stover quality, and (5) increased early vigor. We further discuss cutting-edge tools and approaches to discover, validate, and incorporate novel genetic diversity from exotic germplasm into breeding populations with unprecedented precision, accuracy, and speed. We conclude that the greatest challenge to developing crop varieties to win the race between climate change and food security might be our innovativeness in defining and boldness to breed for the traits of tomorrow

Advances in Plant Breeding Strategies : Nut and Beverage Crops

Peer reviewe

Genetically Modified Plants and Beyond

Genetically Modified Plants and Beyond takes a fresh look at methodologies used in developing crop plants, discusses genome editing, and interrogates the regulatory approaches that different countries are proposing to use to regulate genetically modified (GM) vs genome-edited crop plants. The book focuses on root and tuber crops, ginger, and industrial/oil seed crops. A chapter on the production of pharmaceuticals in plants is also included. Going beyond the usual debate, the book includes case studies from Africa on the adoption of GM crops

Translational Genomics for Crop Breeding: Abiotic Stress, Yield and Quality, Volume 2

Genomic Applications for Crop Breeding: Abiotic Stress, Quality and Yield Improvement is the second of two volumes looking at the latest advances in genomic applications to crop breeding. This volume focuses on advances improving crop resistance to abiotic stresses such as extreme heat, drought, flooding as well as advances made in quality and yield improvement. Chapters examine advances in such key crops as rice, maize, and sugarcane, among others. Genomic Applications for Crop Breeding: Abiotic Stress, Quality and Yield Improvement complements the earlier volume on biotic stressors and will be an essential purchase for those interested in crop science and food production

Legume Crops

In a sustainable agricultural system, legume crops are one of the essential components. However, improving the productivity of legume crops and improving their tolerance to adverse environments are essential tasks for plant biologists. This book includes nine comprehensive chapters addressing various aspects of legume crop biology, production and importance. There are several chapters on the adaptation of legumes to an adverse environment. Particular focus is provided on the sustainable production of legume crops under changing environments. This book will be useful for undergraduate and graduate students, teachers, and researchers, particularly from the field of Crop Science, Soil Science, Plant Breeding and Agronomy

Recent Advances in Genetics and Breeding of Major Staple Food Crops

To meet the global food demand of an increasing population, food production has to be increased by 60% by 2050. The main production constraints, such as climate change, biotic stresses, abiotic stresses, soil nutrition deficiency problems, problematic soils, etc., have to be addressed on an urgent basis. More than 50% of human calories are from three major cereals: rice, wheat, and maize. The harnessing of genetic diversity by novel allele mining assisted by recent advances in biotechnological and bioinformatics tools will enhance the utilization of the hidden treasures in the gene bank. Technological advances in plant breeding will provide some solutions for the biofortification, stress resistance, yield potential, and quality improvement in staple crops. The elucidation of the genetic, physiological, and molecular basis of useful traits and the improvement of the improved donors containing multiple traits are key activities for variety development. High-throughput genotyping systems assisted by bioinformatics and data science provide efficient and easy tools for geneticists and breeders. Recently, new breeding techniques applied in some food crops have become game-changers in the global food crop market. With this background, we invited 18 eminent researchers working on food crops from across the world to contribute their high-quality original research manuscripts. The research studies covered modern food crop genetics and breeding

Plant Stress Physiology

This book includes ten chapters addressing various aspects of plant stress physiology, including plant responses and tolerance to abiotic and biotic stress. These chapters summarize recent findings on the physiological and molecular mechanisms of stress tolerance. They also discuss approaches to enhancing plant productivity via stress tolerance mechanisms. This book is useful for undergraduate and graduate students, teachers, and researchers in the field of plant physiology and crop science

Plant Proteomic Research

Plants, being sessile in nature, are constantly exposed to environmental challenges resulting in substantial yield loss. To cope with harsh environments, plants have developed a wide range of adaptation strategies involving morpho-anatomical, physiological, and biochemical traits. In recent years, there has been phenomenal progress in the understanding of plant responses to environmental cues at the protein level. This progress has been fueled by the advancement in mass spectrometry techniques, complemented with genome-sequence data and modern bioinformatics analysis with improved sample preparation and fractionation strategies. As proteins ultimately regulate cellular functions, it is perhaps of greater importance to understand the changes that occur at the protein-abundance level, rather than the modulation of mRNA expression. This Special Issue on "Plant Proteomic Research" brings together a selection of insightful papers that address some of these issues related to applications of proteomic techniques in elucidating master regulator proteins and the pathways associated with plant development and stress responses. This Issue includes four reviews and 13 original articles primarily on environmental proteomic studies