Increase of histone acetylation by suberoylanilide hydroxamic acid enhances microspore reprogramming and expression of somatic embryogenesis transcription factors in Brassica napus.

In vivo, microspores in the anthers follow the gametophytic development pathway, culminating in the formation of pollen grains. Conversely, in vitro, under stress treatments, microspores can be reprogrammed into totipotent cells, initiating an embryogenic pathway that produces haploid and double-haploid embryos, which are important biotechnological tools in plant breeding. There is growing evidence that epigenetic reprogramming occurs during microspore embryogenesis through DNA methylation, but less is known about the role of histone modifications.

Small molecule inhibitors of human LRRK2 enhance in vitro embryogenesis and microcallus formation for plant regeneration of crop and model species.

In vitro plant embryogenesis and microcallus formation are systems which are required for plant regeneration, a process during which cell reprogramming and proliferation are critical. These systems offer many advantages in breeding programmes, such as doubled-haploid production, clonal propagation of selected genotypes, and recovery of successfully gene-edited or transformed plants. However, the low proportion of reprogrammed cells in many plant species makes these processes highly inefficient.

Opposite Auxin Dynamics Determine the Gametophytic and Embryogenic Fates of the Microspore.

The microspore can follow two different developmental pathways. In vivo microspores follow the gametophytic program to produce pollen grains. In vitro, isolated microspores can be reprogrammed by stress treatments and follow the embryogenic program, producing doubled-haploid embryos.

Dynamics of Endogenous Auxin and Its Role in Somatic Embryogenesis Induction and Progression in Cork Oak.

Somatic embryogenesis (SE) is a feasible in vitro regeneration system with biotechnological applications in breeding programs, although, in many forest species, SE is highly inefficient, mainly due to their recalcitrance. On the other hand, SE represents a valuable model system for studies on cell reprogramming, totipotency acquisition, and embryogenic development. The molecular mechanisms that govern the transition of plant somatic cells to embryogenic cells are largely unknown.

Small molecule inhibitors of mammalian GSK-3β promote in vitro plant cell reprogramming and somatic embryogenesis in crop and forest species.

Plant in vitro regeneration systems, such as somatic embryogenesis, are essential in breeding; they permit propagation of elite genotypes, production of doubled-haploids, and regeneration of whole plants from gene editing or transformation events. However, in many crop and forest species, somatic embryogenesis is highly inefficient. We report a new strategy to improve in vitro embryogenesis using synthetic small molecule inhibitors of mammalian glycogen synthase kinase 3β (GSK-3β), never used in plants.

Stress-Induced Microspore Embryogenesis Requires Endogenous Auxin Synthesis and Polar Transport in Barley.

Stress-induced microspore embryogenesis is a model system of cell reprogramming, totipotency acquisition, and embryo development. After induction, responsive microspores abandon their developmental program to follow an embryogenic pathway, leading to embryo formation. This process is widely used to produce doubled-haploid lines, essential players to create new materials in modern breeding programs, particularly in cereals, although its efficiency is still low in many crop species, because the regulating mechanisms are still elusive.

Pectin De-methylesterification and AGP Increase Promote Cell Wall Remodeling and Are Required During Somatic Embryogenesis of .

Somatic embryogenesis is a reliable system for plant regeneration, with biotechnological applications in trees, but the regulating mechanisms are largely unknown. Changes in cell wall mechanics controlled by methylesterification of pectins, mediated by pectin methylesterases (PMEs) and pectin methyl esterase inhibitors (PMEIs) underlie many developmental processes. Arabinogalactan proteins (AGPs) are highly glycosylated proteins located at the surface of plasma membranes, in cell walls, and in extracellular secretions, with key roles in a range of different processes.

Modulation of autophagy and protease activities by small bioactive compounds to reduce cell death and improve stress-induced microspore embryogenesis initiation in rapeseed and barley.

Microspore embryogenesis is a powerful biotechnological tool that is very useful in crop breeding for the rapid production of haploid and double-haploid embryos and plants. In this in vitro system, the haploid microspore is reprogrammed by the application of specific stress treatments. A high level of cell death after the stress is a major factor that greatly reduces embryogenesis yield at its initial stages.

Autophagy is activated and involved in cell death with participation of cathepsins during stress-induced microspore embryogenesis in barley.

Microspores are reprogrammed towards embryogenesis by stress. Many microspores die after this stress, limiting the efficiency of microspore embryogenesis. Autophagy is a degradation pathway that plays critical roles in stress response and cell death.

Inhibition of Histone H3K9 Methylation by BIX-01294 Promotes Stress-Induced Microspore Totipotency and Enhances Embryogenesis Initiation.

Microspore embryogenesis is a process of cell reprogramming, totipotency acquisition and embryogenesis initiation, induced by stress treatments and widely used in plant breeding for rapid production of doubled-haploids, but its regulating mechanisms are still largely unknown. Increasing evidence has revealed epigenetic reprogramming during microspore embryogenesis, through DNA methylation, but less is known about the involvement of histone modifications. In this study, we have analyzed the dynamics and possible role of histone H3K9 methylation, a major repressive modification, as well as the effects on microspore embryogenesis initiation of BIX-01294, an inhibitor of histone methylation, tested for the first time in plants, in and .