Regulation of biological systems is often achieved through protein–protein interactions. A specific DELLA-SLY1 protein–protein interaction causes destruction of DELLA repressors and promotion of growth in angiosperms. This specificity evolved by the narrowing of a broad ancestral affinity, as is still seen in the liverwort Marchantia polymorpha.

See Ji et al.

Ovules must be maintained in a non-dividing state until being fertilized following pollination. This is achieved by Polycomb repressive complex 2, which maintains the quiescent state of plant eggs by epigenetically silencing the maternal alleles of male genome-expressed genes.

See Wu et al.

Parasitism has evolved independently in plants many times. Plants of the genus Balanophora are obligate parasites of roots and show a consistent pattern of gene loss and genome modification similar to that of other unrelated holoparasites.

See Chen et al.

In lilies, the transition from bulb dormancy to bud growth directly affects multiple developmental processes, including shoot meristem activity, flower transition, inflorescence elongation and cut-flower quality. As part of the process, LoVIL1 epigenetically represses callose synthase from opening plasmodesmata and thus facilitates intercellular communication.

See Pan et al.

Zostera marina is the most widely distributed of all seagrass species, being found in temperate waters across the entire Northern Hemisphere. Nuclear and chloroplast genomics can be used to trace its colonization of the Pacific and expansion across the Canadian Arctic into the Atlantic and down to the Mediterranean.

See Yu, L. et al.

The symbiosis between nitrogen-fixing bacteria and leguminous plants such as Mimosa pudica arose more than 90 million years ago. By comparing transcriptomes from several such plant species, the ancestral state can be established and the developments leading to its current diversity followed.

See Libourel et al.

Rubisco from the red algae Griffithsia monilis has substantially greater catalytic activity than the version found in vascular plants but cannot be successfully expressed in them. Grafting a small number of regions from GmRubisco into the enzyme from Rhodobacter sphaeroides preserves the greater carbon-fixing activity while also allowing expression of the chimeric protein in plants.

See Zhou et al.

Cannabinoids, a family of molecules with many important pharmacological uses, are generally extracted from the flowers of Cannabis sativa. But the leaves of Helichrysum umbraculigerum also contain cannabinoids, and by a different route involving previously unknown cannabinoid metabolites.

See Berman, P. et al.

Trees can be thought to measure out time by the rings on their trunks. J. Alfred Prufrock measured passing time in coffee spoons. Nature Plants measures time in monthly issues; and this is our hundredth.

See Editorial

Kiwifruits are dioecious plants, having separate male and female individuals. Sequencing the genome of three kiwi species demonstrates the evolution of a neo-Y chromosome through translocation of two sex-determining genes.

See Akagi et al.

Sphagnum mosses sequester large quantities of carbon into peatlands. The genomes of Sphagnum species contain sex chromosomes carrying genes that alter the growth and carbon capture characteristics of the two sexes.

See Healey et al.

Plastids follow maternal inheritance. The genetic and environmental factors that regulate this maternal inheritance are now discovered by genetic screens in tobacco, advancing our knowledge of this fundamental subject and having important applications in breeding.

See Chung et al.