Entries by Peter Minorsky

Freeze-Thaw-Induced Embolism and Ultrasonic Emissions in Angiosperms

All organisms including plants share the tetrapyrrole biosynthesis pathway that is critical for the production of compounds such as heme and chlorophyll. During tetrapyrrole biosynthesis, coproporphyrinogen III oxidase (CPO) catalyzes the conversion of coproporphyrinogen III into protoporphyrinogen IX. Pratibha et al. (10.​1104/​pp.​16.​01482) report the results of the characterization of a mutation in the Arabidopsis gene […]

Nematode Cysts and DNA Methylation

Plant-parasitic cyst nematodes (Heterodera species) are among the most devastating pathogens of plant roots. These obligate parasites initiate a long period of biotic interactions with their host plants where formation of an operative feeding structure, the syncytium, is vital for nematode survival and development. The nematode provokes differentially terminated cells in the vascular root tissues […]

Thapisgargin Formation in Thapsia

The Mediterranean plant Thapsia garganica (Apiaceae), also known as deadly carrot, produces the highly toxic compound thapsigargin. This compound is a potent inhibitor of the sarcoplasmic-endoplasmic reticulum Ca2+-ATPase calcium pump in mammals and is of industrial importance as the active moiety of the anticancer drug mipsagargin, currently in clinical trials. Thapsigargin is found in most […]

Suberin and Seed Dormancy

Environmental signals during seed production are important determinants of seed properties, including seed dormancy and seed longevity. The mother plant plays an important role in this signaling process, collecting signals throughout her life history and modulating dormancy by providing hormones to maturing seeds and by plastic development of the tissues surrounding the embryo. This process […]

Blue Light Photoreception by Chlamydomonas

Cryptochromes are flavin-binding proteins that act as blue light receptors in bacteria, fungi, plants and insects and are components of the circadian oscillator in mammals. Animal and plant cryptochromes are evolutionarily divergent, although the unicellular alga Chlamydomonas reinhardtii has both an animal-like cryptochrome and a plant cryptochrome (pCRY; formerly CPH1). Müller et al. (10.​1104/​pp.​17.​00349 ) […]

Insights into Salicylic Acid and Mitochondria

Within the mitochondrial electron transport chain, complex II (succinate dehydrogenase [SDH]) oxidizes succinate to fumarate by transferring electrons to ubiquinone (UQ), which is reduced to ubiquinol. The enzyme is formed by four subunits: a flavoprotein (SDH1), which contains the FAD cofactor, an iron sulfur (Fe-S) protein (SDH2) housing three Fe-S clusters, and two small integral […]

The Root Greening Response in Arabidopsis

Based on various developmental, environmental, and hormonal cues, proplastids can be converted into different types of plastids within cells. In Arabidopsis, chloroplast development is repressed in roots via auxin signaling. When roots are detached from the shoot, and its supply of auxin, roots develop chloroplasts. The expression levels of key chlorophyll biosynthesis genes are correlated […]

Monitoring the Dynamics of Freezing in Trees

Ice formation within plants influences their physiology mechanically, hydraulically, and at a cellular level. Mechanical strain occurs as water expands during freezing and tension is induced in the remaining liquid-phase sap. Xylem cavitation is initiated upon freezing due to the low (i.e. negative) water potential of ice and the low solubility of gases in ice. […]