Entries by Peter Minorsky

Variations in Leaf Intercellular Air Spaces

During the course of evolution, the invasion of lands by  plants exposed plant tissues to air, 
which dramatically lowered the resistance for CO2 diffusion to chloroplasts by ~10,000-fold. The evolutionary development of the leaf intercellular airspace was a key innovation that allowed land plants to profit from the lowered resistance to CO2 diffusion afforded by […]

Long-Days Enhance Jasmonic Acid-Related Plant Defense 

Depending on the species, daylength profoundly affects the timing of key developmental transitions in plants, including, floral initiation, tuberization, and bud set and growth cessation in trees. To explore additional effects of daylength on plant function, Cagnola et al. (10.1104/pp.18.00443) investigated the transcriptome of Arabidopsis plants grown under short days (SD) and transferred to 
long days […]

Diterpenoid Metabolism in Switchgrass

Switchgrass (Panicum virgatum) is a perennial C4 grass native to North America primarily valued as a next-generation feedstock for biofuel production. Its high net energy yield and 
wide habitat range make switchgrass an attractive crop for cultivation on marginal lands with minimal agronomic inputs, thus promising environmentally sustainable bioenergy production. 
However, increasing drought stress 
and accompanying […]

NO2 Enhances Pathogen Resistance

Nitrogen dioxide (NO2) forms in plants under stress conditions, but little is known about its 
physiological functions. Using a variety of techniques, Mayer et al. (10.1104/pp.18.00704) have examined the effects of fumigating Arabidopsis with 10 ppm NO2 for 1 h, a treatment that does not cause 
visible leaf symptoms or ion leakage. Although visual symptoms […]

Annexins Facilitate Post-Phloem Sugar Transport

Because local sugar concentrations play a critical role in regulating root growth, it is important to learn more about the mechanisms that control sugar transport into the growing zones of the 
root. It has previously been proposed that once translocated sugar reaches the interface between conducting phloem and sink tissues in the root, it is unloaded […]

A Lipid Synthesis Enzyme Confers Freezing Tolerance

Despite major advances in understanding cold signaling, cold acclimation, and freezing protection in model and crop species, and extensive studies of natural variation in freezing tolerance in Arabidopsis accessions, the question of which genes and mechanisms underlie freezing tolerance of wild species has remained largely unanswered. Because freezing tolerance generally exhibits continuous variation, it is […]

How Ethylene Reddens Apples

Ethylene is essential for the ripening of climacteric fruits, and a rapid burst of ethylene production and a rise in respiration occur at the transition to ripening.  In ripening apple (Malus domestica) fruits, the accumulation of anthocyanins that is responsible for reddening is correlated with ethylene release but how precisely are the two processes related? […]

Etioplasts: The Role of Digalactosyldiacylglycerol

In dark-grown plants, the plastids of cotyledon cells develop as etioplasts. Etioplasts contain unique internal lattice membrane structures called prolamellar bodies (PLBs) and lamellar prothylakoids (PTs). PLBs accumulate protochlorophyllide (Pchlide), a chlorophyll intermediate, in a complex with NADPH and an enzyme called light-dependent NADPH:Pchlide oxidoreductase (LPOR). Two galactolipids, namely monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), are […]