Reviews & Analysis

Sporopollenin, which encapsulates gametes in spore and pollen grains, is probably the most chemically inert biopolymer. This inertness is essential for gamete protection, but also hinders the elucidation of sporopollenin molecular structure. Now, the macromolecular network forming sporopollenin is described in unprecedented detail.

Light is a critical environmental factor that influences nutrient uptake in roots and the subsequent use of nutrients, which is necessary to sustain plant growth. The positive effect of red light on phosphorus uptake has now been defined, along with the pivotal role of the phytochrome-B signalling cascades that mediate this effect.

Cellular components can be digested in the vacuole by autophagy, a critical process for homeostasis and stress tolerance. Functions of this recycling pathway in maize have now been defined, including lipid degradation, control of secondary metabolism and remodelling of the proteome.

How plants control the composition of proanthocyanidins has been the subject of much interest and speculation. The elucidation of parallel routes to the starter and extension units in Medicago provides an explanation.

Plant nutrient-uptake involves the growth and maintenance of viable root hairs that are flexible but resistant to soil hardening, water content variability and pathogen attack. A role for phosphoinositides establishing polarity and structural hardening of the cell wall is now defined, linking lipid signalling and membrane trafficking to cellular morphology.

Chromosome-scale assemblies are quickly becoming the standard for high-quality de novo reference plant genomes. Combining nanopore technology sequencing and optical map information is one way to achieve this.

The insidious control over farming practices exercised by seed companies is an example of how powerful actors in the agri-food system promote profit over environment and health. More important, is the question of how we can shape a more desirable farming system that works for farmers, the public and the environment.

Domestication of the citrus family has resulted in the selection of key alleles of a duplicated MYB transcription factor called Ruby.

Leaf senescence plays a crucial role in nutrient recovery in late-stage plant development and requires vast transcriptional reprogramming by transcription factors such as ORESARA1 (ORE1). A proteolytic mechanism is now found to control ORE1 degradation, and thus senescence, during nitrogen starvation.

Plants synthesize a diversity of cell walls to fit the needs of different cell types and phases of development. A group of transcription factors has now been identified that governs formation of one type of primary cell wall.

Can genomics, functional analysis and genome editing help build the bridge between orphan crops and modern agriculture?

Plants’ photosynthetic capacity at high light is limited by the kinetics of the slow, carbon-dioxide-fixing enzyme Rubisco. Increasing Rubisco content in a C₄ crop plant is now shown to enhance photosynthesis and growth.

Seasonal control of flowering is a dramatic example of interactions between genes and environment, and is mostly studied in growth chambers. However, switching from natural settings to artificial conditions affects phenotypes. More natural responses in cabinets can be obtained by only modifying a few environmental parameters.

Integration of transcriptome profiles, epigenomic marks and chromatin-accessible regions highlights the conserved regulatory circuits governing ripening of fleshy fruits and unveils similarities with the development of dry fruits.

Biennial plants require exposure to the cold of winter to overcome a block to flowering in the spring. The molecular role of FRIGIDA, a key component of the system that establishes the cold requirement in Arabidopsis, is to assemble a protein super-complex that promotes expression of a flowering repressor in the autumn.

Plants are amazing chemical factories. Within the plant kingdom, more than 450 distinct fatty acid structures have been described. Two new C₂₄ dihydroxy fatty acids have now been discovered that are synthesized by an unprecedented biosynthetic route termed ‘discontinuous elongation’.

Ploidy differences in sex-linked genes typically produce gene expression imbalances between the sexes. A two-sex plant offers a solution for the early stages of resolution of this gene expression imbalance, very much reminiscent of a model proposed for mammals 50 years ago.

Self-compatible diploid potatoes have been developed by knocking out the self-incompatibility gene S-RNase using CRISPR–Cas9 editing, opening new avenues for diploid potato breeding.

Cell walls made mainly of polysaccharides are a distinguishing feature of plants. They play key roles in adaptation today and during pivotal evolutionary events, such as colonization of dry land and development of a water-conducting vascular system. A critical enzyme involved in cell wall biosynthesis has now been identified.

The reference genomes of two fern species shed light on fern genome evolution and fern-cyanobacterial symbiosis, paving the way for understanding the unique and interesting biology of ferns.