De novo induction of a DNA-histone H3K9 methylation loop on synthetic human repetitive DNA in cultured tobacco cells

Epigenetics in the modern era of crop improvements

Epigenetic mechanisms are integral to plant growth, development, and adaptation to environmental stimuli. Over the past two decades, our comprehension of these complex regulatory processes has expanded remarkably, producing a substantial body of knowledge on both locus-specific mechanisms and genome-wide regulatory patterns. Studies initially grounded in the model plant Arabidopsis have been broadened to encompass a diverse array of crop species, revealing the multifaceted roles of epigenetics in physiological and agronomic traits. With recent technological advancements, epigenetic regulations at the single-cell level and at the large-scale population level are emerging as new focuses. This review offers an in-depth synthesis of the diverse epigenetic regulations, detailing the catalytic machinery and regulatory functions. It delves into the intricate interplay among various epigenetic elements and their collective influence on the modulation of crop traits. Furthermore, it examines recent breakthroughs in technologies for epigenetic modifications and their integration into strategies for crop improvement. The review underscores the transformative potential of epigenetic strategies in bolstering crop performance, advocating for the development of efficient tools to fully exploit the agricultural benefits of epigenetic insights.

Rhizobium rhizogenes-mediated hairy-root transformation of daughter plants from the model strawberry Fragaria vesca's stolons

Strawberry, a member of the Fragaria genus within the Rosaceae family, is one of the most cherished fruits worldwide. This perennial herbaceous plant also serves as a model for studying the Rosaceae family. Despite the complex polyploidy of strawberries, extensive efforts in traditional breeding over the years have resulted in improvements in yield, fruit size and shape, berry quality, and various other aspects of strawberry production. However, in addition to these conventional methods, advanced genetic technologies such as genetic modification and gene editing in intricate polyploidy varieties of strawberry are also required. Here, we present the Rhizobium rhizogenes-mediated hairy-root transformation of daughter plants from the model strawberry Fragaria vesca's stolons (also called runners), which exhibit diploid genomes. As a case study, new daughter plants were cut from the stolons, infected with R. rhizogenes harboring the mVENUS gene under Cauliflower mosaic virus 35S promoter, and then transferred on vermiculite-filled pots. After a couple of months of growth, fluorescence was observed in a few adventurous roots of the daughter plants. The hairy root transformation of daughter plants isolated from its vegetative propagation circumvents the need for seed production or callus formation and subsequent plant regeneration, which are often problematic for maintaining preferred genetic traits in complex ploidy levels. This method, which excludes genetic modification of the above-ground parts, especially the edible fruits, will open new avenues for strawberry breeding, particularly in the areas of plant nutrient absorption and fostering growth through interactions with microorganisms.

Plant Artificial Chromosomes: Construction and Transformation

With the decline of cultivated land and increase of the population in recent years, an agricultural revolution is urgently needed to produce more food to improve the living standards of humans. As one of the foundations of synthetic biology, artificial chromosomes hold great potential for advancing crop improvement. They offer opportunities to increase crop yield and quality, while enhancing crop resistance to disease. The progress made in plant artificial chromosome technology enables selective modification of existing chromosomes or the synthesis of new ones to improve crops and study gene function. However, current artificial chromosome technologies still face limitations, particularly in the synthesis of repeat sequences and the transformation of large DNA fragments. In this review, we will introduce the structure of plant centromeres, the construction of plant artificial chromosomes, and possible methods for transforming large fragments into plant cells.