Secondary growth from the vascular cambium, a lateral meristem, increases the plant’s girth. It also produces wood (secondary xylem) and important fibers like flax, jute and hemp (secondary phloem). Ragni and Greb review secondary growth in plants. They start with a review of the evolutionary history of secondary growth (which includes both gains and losses), […]
Some plants are able to suppress inbreeding through a system called self-incompatibility, in which “self”-pollen is unable to reach “self” eggs. Self-incompatibility has evolved multiple times and takes several forms. Goring reviews the cellular processes of self-incompatibility that occur in Brassicaseae in pollen-stigma interactions, the “first checkpoint in pollen selection”. Pollen coat proteins are involved […]
Plasmodesmata are tiny channels between cells that allow intercellular movement of messages and metabolites as well as pathogens. They are structurally complex and usually have a central strand of endoplasmic-reticulum (the desmotubule) that passes between adjacent cells, connected by spoke-like elements to the plasma membranes that line the channel. Nicolas et al. speculate on how […]
Small molecules are crucial for the recognition of friends and foes. For example, Nod factors are N-acetylglucosamine-derived “friend” signals produced by bacterial microsymbionts. Chitin is an N-acetylglucosamine-derived fungal wall polymer that plants perceive as indicating the presence of an enemy. The question of how plants perceive their friends and enemies became even more perplexing when […]
Cell division in plants is a structurally beautiful process that involves striking and dynamic changes in the cytoskeleton, endomembranes, and nucleus. However, as authors Smertenko et al. observe, “Current plant cytokinesis terminology was developed using data generated by fluorescence microscopy of live or fixed cells, electron microscopy of chemically or cryofixed cells, and genetic strategies,” […]
Photosynthesis in aquatic organisms is made difficult due to the low solubility of CO2 in water. Algae such as Chlamydomonas rheinhardtii overcome this limitation through a carbon-concentrating organelle called a pyrenoid. Two papers in Cell redefine our understanding of the pyrenoid structure. Mackinder et al. (10.1016/j.cell.2017.08.044) tagged pyrenoid-localized proteins and examined their locations as well […]
Plants are known for their ability to regenerate tissues following wounding. Wound repair requires the induction of cell proliferation, leading to the formation of undifferentiated callus at the wound site, followed by cell differentiation. Ikeuchi et al. explored transcriptional changes following wounding damage to the hypocotyl, and through mutant analysis and measurement of hormones evaluated […]
Vitamin E (alpha-tocopherol and related tocochromanol compounds) is a lipid-soluble antioxidant that contributes to numerous cellular activities and confers protection against many diseases, from cancer to cardiovascular disease. The main sources of vitamin E for humans are plant oils, but most crop seeds produce tocopherols with only low vitamin E activity. The biosynthetic pathway of tocochromanols […]
Liu et al. used models to predict the effects of climate change on tree mortality in 13 temperate and tropical forest biomes across the globe. When only increased temperature and changes in precipitation are considered, mortality increases in most biomes, with higher emissions models leading to increased mortality. However, when increases in CO2 concentration are […]