Entries by Peter Minorsky

Actin and Aphid Feeding

Remodeling of the actin network in plant cells involves the severing, depolymerization and polymerization of F-actin.  A variety of actin-binding proteins are involved in remodeling of the actin cytoskeleton, including the actin-depolymerizing factor (ADF) family of proteins. As a result of their ability to sever and depolymerize F-actin and yield products with ends that can serve as […]

Origin and Role of ABA in Stomatal Regulation

When the vapor pressure difference (VPD) between a leaf and the atmosphere increases (i.e., when air humidity decreases), guard cells lose turgor, thereby leading to stomatal closure. The evolution of this mechanism was an important step in the colonization of land by plants, since it enabled plants to control water loss when they were exposed […]

Extracellular ATP Boosts Plant Immunity Via Jasmonate Signaling

Damage-associated molecular patterns (DAMPs) are endogenous chemicals that are released from damaged cells and which play a role as “danger signals.” 
Adenosine 5’-triphosphate (ATP) becomes a DAMP signal after release into the extracellular milieu following cellular damage. Extracellular ATP is recognized at the cell surface by purinoceptors, where it evokes immune responses and wound healing. […]

Nitric Oxide and Diatoms

All gases in the N cycle, including nitric oxide (NO), are present in oceans, either because of gas exchanges at the air-water interface or because they are produced within oceans themselves. NO, a physiologically important gaseous transmitter, is generated in seawater by nonbiological photochemical reactions, large-scale electrical discharges, and enzymatic activities in organisms living in […]

A MicroRNA Affecting Grain Yield in Rice

MicroRNAs (miRNAs), a class of abundant small noncoding RNAs, have been identified as important regulators of gene expression in plants, affecting many aspects of plant development. Recently, several miRNAs have been reported to regulate rice grain yield. A previous study revealed that miR397 regulates rice grain yield by affecting a blue copper protein, laccase. This […]

Xylem Sap Surface Tension and Hydraulic Safety

Xylem embolisms are induced by drought stress and/or freezing stress by means of “air-seeding,” that is the aspiration of gaseous bubbles into xylem conduits from adjacent gas-filled compartments via the pits. At water potentials less negative than the threshold for air seeding, the air-water interface is stabilized by the surface tension (γ) of the xylem […]

Chemical Defenses of Maize Roots

Of the many classes of natural products produced by plants, terpenoids are the most structurally diverse, with well over 25,000 established compounds. In maize (Zea mays), terpene olefins are nearly ubiquitous components of induced volatile emissions following biotic stress. In contrast to our understanding of foliar volatiles, much less is known about the volatile emissions […]

New Insights into Wound-Induced Callus Formation

Plants repair wound sites through the formation of unorganized cell masses called calli, which can also serve as progenitors of new organs. Callus formation and organ regeneration often entail cell cycle re-entry of quiescent cells, which is achieved through the re-activation of core cell cycle regulators CYCLIN (CYC) and CYCLIN-DEPENDENT KINASES (CDK). Recent studies have […]

Lignin Bioengineering in Poplar

Lignified cell walls constitute an important renewable and sustainable feedstock for the production of fermentable sugars, biochemicals, and biomaterials.  In biorefineries, plant cell wall polysaccharides are depolymerized into simple monomeric sugars, a process called saccharification. These sugars are subsequently fermented to ethanol or other compounds by microbes. However, the complex chemical composition and physical structure […]