Entries by Peter Minorsky

Multiple Phytohormone Screening Method

Phytohormones are naturally occurring signaling molecules that play key roles in the regulation of plant physiology, development, and adaptation to environmental stimuli. Generally, their concentrations in plant tissues are extremely low (fmol-pmol/g fresh weight, FW). Although certain phytohormones are usually related to specific biological functions or responses, there is increasing evidence that plant hormone signaling […]

Origin of Plant R Genes

Plants rely on two branches of the innate immunity system to prevent or eliminate microbial infections: one involves cell surface receptors to respond to pathogen- or microbe- associated molecular patterns, and the other acts inside plant cells by using proteins with nucleotide-binding site (NBS) and Leu-rich repeat (LRR) domains. NBS-LRR proteins confer recognition of pathogen […]

Phosphorous Deficiency and Photosynthesis

Phosphorus (P) is an essential macronutrient, and P deficiency limits plant productivity. P influences many aspects of photosynthesis P-deficient plants typically remain green and do not develop leaf chlorosis and yet P starvation immediately affects CO2 assimilation. Specifically, P deficiency is believed to affect CO2 assimilation by reducing the ATP-dependent regeneration of ribulose-1,5- bisphosphate in […]

Leaf Metabolism in Response to Dark

One of the more prevalent methods used to initiate plant senescence under laboratory conditions is to grow plants in prolonged dark conditions. The course of “dark-induced senescence” depends upon whether individual leaves on the plant or the entire plant is darkened: an individually darkened leaf initiates senescence much more rapidly than the leaves of an […]

Iron Accumulation and Fraxetin, a Coumarin

Soil pH has a strong influence on the availability of mineral nutrients and the distribution of species in natural plant communities. Iron (Fe) solubility decreases dramatically with increasing pH. In alkaline soils, calcifuge (“chalk-fleeing”) species are unable to compete due to their inability to acquire sufficient Fe. Calcicole behavior, i.e. the ability to thrive on […]

Calcium Dynamics in Chloroplasts

Transient changes in intracellular free Ca2+ concentration ([Ca2+]) are involved in the sensing of a wide variety of abiotic and biotic stimuli iIn plants. The unique spatiotemporal patterns in [Ca2+] that result enable specific stimulus-response coupling. Several intracellular compartments of the plant cell participate in Ca2+ homeostasis, including the vacuole, endoplasmic reticulum, mitochondria, and plastids. […]

The Origins of Protein Storage Vacuoles

During seed development, protein reserves and minerals are stored in specialized vacuoles called protein storage vacuoles (PSVs). PSVs are functionally different from the lytic vacuoles (LVs) that serve a lysosome-like role in vegetative plant tissues. Embryonic vacuole (EVs) are also present during early embryogenesis. Later, during the maturation phase of seed development, PSVs arise to […]

Trehalose-6-Phosphate and Reproductive Resource Allocation in Maize

Flowering is a developmental stage that is particularly sensitive to drought; restriction of water at this time can decrease seed set, final seed number, and harvested seed yield. Kernel abortion during drought at flowering can be alleviated by supplying Suc to reproductive tissue. Consequently, Suc metabolism in reproductive tissue has been proposed as a target […]

Systemic RNA Silencing in Tobacco

gene RNA silencing is a cellular gene regulatory mechanism that is conserved across fungal, plant, and animal kingdoms. Through sequence-specific targeting, RNA silencing can degrade mRNA for posttranscriptional gene silencing (PTGS) or modify related DNA for transcriptional gene silencing. RNA silencing can spread from cell to cell and over long distances in animals and plants. […]