How do cells know when it is time to divide? Helt et al. explore this question using the single-celled alga Chlamydomonas. Unlike most animal and fungal cells, which tend to maintain a relatively consistent size by dividing after their size has doubled, Chlamydomonas cells can undergo several rounds of size doubling during daylight, followed by […]
Sometime around 1.8 to 2 billion years ago, complex eukaryotic cells appeared for the first time, providing the ancestor for plants, animals and fungi. Many lines of evidence have indicated that this event probably involved an ancient archaeon taking up an ancient bacterium, the progenitor of all mitochondria. Genomic studies point to the ancient archaeon […]
Filamentous pathogens (fungi and oomycetes) use a variety of tactics to obtain nutrients from plants. Classically, they have been categorized as biotrophic (“eating” living tissues), nectrotrophic (eating dead tissues) or hemibiotrophic (biotrophic followed by heterotrophic). Hane et al. point out that these categories are imperfect and difficult to asssign and propose a new approach, based […]
Tamburino et al. analyzed text from more than 12,000 research articles published in the past 50 years that included the terms “global” or “world” and “food supply”, “food demand’, or “zero hunger”. From this dataset, they quantified terms related to population, total food production, or per-capita demand (e.g., through different types of diets). Across this […]
Review. Small RNAs and extracellular vesicles: New mechanisms of cross-species communication and innovative tools for disease control We have only recently begun to appreciate the phenomenon of cross-species or cross-kingdom small RNA transfer, and its applications. Using examples from plants and animals, Cai et al. summarize how some pathogens have evolved the capacity to introduce […]
Mitochondrial metabolism provides ATP and reducing power to drive myriad reactions in the plant cell, and is constantly being fine-tuned in response to environment and demands. Post-translational modifications (PTMs) of proteins, including redox reactions of methionine and cysteine and carbamylation of lysine, arginine and proline, are crucial for this rapid, reversible responsiveness. The rate of […]
Crassulacean acid metabolism (CAM) is a water-conserving strategy in which stomata open at night and carbon is stored until daytime photosynthesis provides the energy to fix it. This special issue of the Journal of Experimental Botany, edited by Hultine, Cushman, and Williams, brings together a set of papers that explore new insights into the evolution […]
During leaf senescence, nitrogen-rich chlorophyll is broken down through a regulated process so that nitrogen-containing compounds can be reassimilated into the plant body. Chlorophyll catabolites are sequestered in the vacuole as linear tetrapyrroles known as phyllobilins, produced through the action of the porphyrin ring-opening activity of PHEOPHORBIDE A OXYGENASE (PAO); this is known as the […]
The rate of mitochondrial respiration is highly dynamic and responds to numerous endogenous and exogenous factors. Here, O’Leary et al. have measured mitochondrial respiration (through O2 production) in response to various metabolites in leaf discs over several hours, to address not only post-translational controls but also de novo transcriptional/translational effects. They found that, as expected, […]