Recent Posts

Nanoscale movements of cellulose microfibrils in primary cell walls ($)

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Cell walls are complex mixtures of cellulose microfibrils, proteins and other materials. Their mechanical properties can be measured and modeled, but it is not always simple to translate these measurements to changes at the molecular level. Zhang et al. used atomic force microscopy to provide an unprecedented…

Glucosylation prevents plant defense activation in phloem-feeding insects (Nature Chem. Biol.)

Brassicas produce specialized metabolites called glucosinolates that can be enzymatically converted to release toxic compounds. The catalyzing enzyme is stored in a separate subcellular compartment, so upon wounding by a herbivore the enzyme and substrate mix and release the toxin. Phloem-feeding insects…

Small subunits can determine enzyme kinetics of tobacco Rubisco expressed in Escherichia coli (Nature Plants)

Rubisco is the enzyme responsible for the fixation of CO2 to ribulose-1,5-bisphosphate (RuBP) during photosynthetic reactions. However, this enzyme has some functional issues, such as a slow catalytic turnover rate and sensitivity to temperature and CO2, and it catalyzes a competing oxygenation process…

Review: Plant small heat shock proteins – evolutionary and functional diversity (New Phytol.)

Heat shock proteins are rapidly induced by heat treatment and were among the first plant genes and proteins characterized in the early days of molecular biology, nearly 40 years ago. Waters and Vierling review the family of small heat shock proteins (sHSPs), which has been especially amplified in plants…

Highly active rubiscos discovered by systematic interrogation of natural sequence diversity (EMBO J)

This is a fascinating and very well-written paper that investigates the diversity of rubisco's kinetic properties. Rubisco’s relationship with its substrate CO2 is complicated by its relationship with O2, and it has often been suggested that for this reason rubisco is locked into a slow rate of catalysis.…

Review: Enzymes as parts in need of replacement – and how to extend their working life (Trends Plant Sci)

The ability of biological systems to self-repair is a huge motivator in all sorts of synthetic biology projects. Taking this cell-as-factory to the next step comes the question of how often do the parts need replacing? Tivendale et al. address this through a discussion of Catalytic Cycles until Replacement…

Endosidin20 targets the cellulose synthase catalytic domain to inhibit cellulose biosynthesis (Plant Cell)

Cellulose is an indispensable component of plant cell wall formation. Cellulose is synthesized at the plasma membrane by a cellulose synthase complex (CSC) made up of at least 18 monomeric cellulose synthases (CESAs). In this study, Huang et al. used a chemical genetic approach to explore the structure…

Direct conversion of carlactonoic acid to orobanchol by cytochrome P450 CYP722C in strigolactone biosynthesis

Strigolactones (SL) are a compounds that play important roles as phytohormones and as a rhizosphere signaling. Despite the great advances in their research that occurred recently, their biosynthetic pathway is still not well understood. Until now, the pathway leading to the precursor carlactonic…

Pheophorbide a may regulate jasmonate signaling during dark-induced senescence

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…

Attractive flower smell turned into defense barrier

Boachon et al. explore metabolic processes associated with floral defense. Plant Cell https://doi.org/10.1105/tpc.19.00320 By Benoît Boachon, University of Lyon, UJM-Saint-Etienne, CNRS, BVpam FRE 3727, Saint-Etienne, France. Danièle Werck-Reichhart, Institute of Plant Molecular Biology of…