Reviews & Analysis

Only a limited subset of angiosperms produce cannabinoids. Evidence for the independent evolution of cannabinoid biosynthesis was discovered in the South African plant Helichrysum umbraculigerum. This discovery provides an alternative set of enzymes that will expand the synthetic biology toolbox for those interested in manipulating the pathway for drug discovery.

Photorespiration is known to be involved in carbon flux in plants, enabling the carbon lost during RuBisCO oxygenation to be recovered. We show that NPF8.4 is a transporter responsible for sequestering the photorespiratory carbon intermediate glycerate into vacuoles during nitrogen depletion, elucidating a novel function for photorespiration in nitrogen flux.

Maximization of reproductive success is critical for plant fitness. To this end, the flowering process must be finely tuned. We show that the rice florigen-like protein FT-L1 contributes to plant entrance into the reproductive phase and enables a balanced progression of inflorescence development.

A genetic approach that combines forward genetics with dynamically targeted genome-scale CRISPR–Cas9 tools has been developed to unmask phenotypic variation in Arabidopsis thaliana that is otherwise hidden by functional redundancy. This approach, called Multi-Knock, should be readily deployable by scientists and breeders for basic research and to expedite breeding efforts.

Gossypol is a defense compound in cotton; both axially chiral gossypol enantiomers confer pest resistance, but (−)-gossypol is toxic for humans. We identified a gene (GhDIR5) that selectively promotes (−)-gossypol synthesis. GhDIR5 knockout enabled the production of (−)-gossypol-depleted cottonseeds without affecting pest resistance.

Sequences of almost 800 wheat genomes have retraced the history of wheat: when and where it was domesticated, how cultivation spread from its Middle Eastern centre of origin and how the genome adapted to selective pressures in new agricultural habitats, not least thanks to its ability to take up genes from wild cousins.

A tethering approach based on a LexA–CENH3 fusion protein in maize activates functional centromeres at synthetic LexO repeat arrays. The synthetic centromeres cause fragmentation of the resulting dicentric chromosomes, resulting in stably inherited and self-sustaining neochromosomes.

Kiwifruit are a dioecious species with genetic sex determination that involves genes in a male-specific region of the Y chromosome. One Y-encoded sex determining gene, Shy Girl, also controls sexually dimorphic traits. This property can explain our observation of recurrent recent changes in these genes’ location in related species.

Plant gene silencing is usually achieved through chromatin modifications and repressive transcription factors. We used a gain-of-function approach in Arabidopsis that identified 14 proteins that can repress gene expression via diverse epigenetic pathways, including DNA methylation, histone modifications and interference with RNA polymerase II transcription.

Using leaf explants and morphological regulator genes (Babyboom and Wuschel 2) driven by new promoter combinations, an efficient transformation and genome editing system is developed in maize and sorghum and successfully applied in seven other Poaceae grass species.

Various clades of legume plants irreversibly modify the development of their symbiotic nitrogen-fixing microorganisms. Key transcription factors controlling this process have been identified. They are conserved and functional even in plant species that do not induce such a terminal differentiation.

During evolution, the acquisition of special types of cells and tissues requires new regulatory genes that control cell division and cell differentiation. Here, we found that stomatal basic helix-loop-helix (bHLH) transcription factors are co-opted for the development of seta in the liverwort Marchantia polymorpha, which lacks true stomata.

In Arabidopsis, the final size of the seed is determined early on during its development by the growth of a single multinucleate cell, the coenocytic endosperm. The endosperm arises from a second fertilization event, alongside the embryo, and dominates the onset of seed development while later nourishing and supporting embryo growth.

Plant cells possess a bewildering number of different intracellular transport routes. A comprehensive interactome-based analysis on a set of core players unravels novel common components and surprising connections.

The maternal inheritance of organelles (such as chloroplasts and mitochondria) is the rule in most eukaryotes. In tobacco, chilling stress during pollen development and deactivation of an exonuclease that degrades organellar DNA facilitate paternal plastid transmission, thereby revealing that both genetic and environmental factors determine organelle inheritance.

Mutations in two single genes (AtPS1 and AtJAS) in Arabidopsis thaliana are individually sufficient to restore haploid male fertility with no effect on haploid female fertility. Genes restoring haploid male fertility can bypass laborious and resource-intensive chemical methods, thereby markedly increasing the efficiency of doubled haploid (DH) technology to accelerate crop breeding.

In plant mitochondria, NADH dehydrogenase (complex I) and the cytochrome bc₁ complex (complex III) form a I + III₂ supercomplex, which is thought to stabilize the structure of the component complexes. Protein–protein interactions at three sites on the membrane arm of complex I partly resemble those in mammals, but also have plant-specific features.

Analysis of cambial development in the tree Populus trichocarpa reveals how a zinc-finger transcription factor, Populus trichocarpa VASCULAR CAMBIUM-SPECIFIC 2 (PtrVCS2), controls the rate of cell proliferation by changing the dynamics of histone acetylation at the Populus trichocarpa WUSCHEL-RELATED HOMEOBOX4a (PtrWOX4a) promoter.

Plants often need to bend their organs during their growth and development. It is a complex process, and the different mechanisms involved are discussed in the light of recent findings about genes, signalling, modelling and biomechanics.

This review explores recent advances in research on the regulatory and evolutionary mechanisms of plant specialized metabolism and extrapolates these findings to medicinal plants that synthesize rare molecules.