Entries by Estee Tee

Orange Is the New Green: Arabidopsis ORANGE Represses Chloroplast Biogenesis

Chloroplast development in germinating seedlings initiates upon illumination. Whereas chloroplasts in true leaves develop directly from proplastids, chloroplasts in cotyledons of dark-grown seedlings develop from an intermediate type of plastid called an etioplast. During development, etioplasts accumulate carotenoids and protochlorophyllides in their prolamellar bodies. Once seedlings emerge from the soil into the light, de-etiolation occurs […]

Local manufacturing: a center for photosystem biogenesis

Photosystem biogenesis in the chloroplast requires a concerted effort between synthesis and assembly of components including protein subunits, pigments, and other cofactors that varies both temporally and spatially. Sun, Valente-Paterno et al. (2019) investigate the translation zone (T-zone) of unicellular alga Chlamydomonas reinhardtii (Chlamydomonas) chloroplasts as the primary location for biogenesis of photosystems I and […]

Promoting production: UPL3 promoter variation modulates seed size and crop yields

Identifying natural genetic variation, understanding how it influences traits, and utilizing it for crop improvement is a major objective in plant science. Miller et al. (2019) have identified genetic variation in the promoter region of BnaUPL3.C03 from a panel of Brassica napus accessions that can influence seed size, lipid content and final crop yield. They […]

Too Much, Take it Back: PAP Moves from the Cytosol to Plastids and Mitochondria for Degradation via PAPST2

Plants need to strike a fine balance between the production, transport, and degradation of stress signals in order to optimize growth in fluctuating environmental conditions. The signal 3’phosphoadenosine 5’phosphate (PAP) accumulates during drought and light stress and induces stress-responsive gene expression (Estavillo et al., 2011). Sulfur transfer from 3’phosphoadenosine 5’phosphosulfate (PAPS) to acceptor compounds in […]

Uncovering the Steps Before: Sulfate Induces ABA Biosynthesis and Stomatal Closure

Plant stomatal aperture regulation via guard cells is an example of how plants dynamically process environmental signals to induce a physiological response. The drought stress hormone abscisic acid (ABA) is a well-characterized signal that induces stomatal closure, preventing water loss. ABA acts via the PYRABACTIN RESISTANCE (PYR)/PYR LIKE (PYRL)-ABA INSENSITIVE1 (ABI1)-OPEN STOMATA1 (OST1) receptor-phosphatase-kinase core […]

Active Support: GHR1 is a Pseudokinase that acts as a Scaffolding Component

Plants balance CO2 uptake with water loss via a complex network of signals regulating stomatal aperture size. Stomata close in response to a number of stimuli, including drought, low light intensity, low air humidity, elevated intercellular CO2 concentration, pathogens, and certain air-borne chemicals or pollutants such as ozone. After plants perceive these triggers, multiple signaling […]