Recent Posts

Jasmonic acid and salicylic acid signaling in fern Azolla filiculoides and its cyanobiont

The phytohormones jasmonic acid (JA) and salicylic acid (SA) play key roles in how plants respond to microbes. However, this interplay between JA, SA and microbes is less understood in non-angiosperm linages. de Vries and colleagues examine JA/SA signalling between the water fern Azolla filiculoides…

Ancient duons may underpin spatial patterning of gene expression in C4 leaves

C4 photosynthesis describes a biochemical CO2-concentrating mechanism that relies on the spatial separation of biochemistry between two cell types, mesophyll cells (MCs) and bundle sheath cells (BSCs). However, there is currently little evidence on how some genes are preferentially expressed in BSCs…

Dynamic thylakoid stacking regulates the balance between linear and cyclic photosynthetic electron transfer

The activation of photosynthetic electron transport upon a dark-to-light transition occurs prior to the initiation of CO2 fixation by Rubisco in the Calvin cycle.  A mechanism known as cyclic electron transfer (CET) exists that generates the proton motive force required to drive ATP synthesis without…

RAF2 is a Rubisco Assembly Factor in Arabidopsis thaliana

The assembly of the carbon fixing enzyme Rubisco is a complex process and involves many chaperones including RAF1, RbcX and the chaperonins. Recent evidence pointed to the existence of another chaperone, RAF2, conserved among photosynthetic organisms. The protein has similarity to pterin-4α-carbinolamine…

Genome downsizing, physiological novelty, and the global dominance of flowering plants

PLOS Biol. Guard cell size is, in general, inversely related to stomatal density. It is advantageous for plants to maximize their photosynthetic capabilities by generating higher rates of gas exchange, thereby incorporating more CO2 to help drive this pathway. However, the number of cells that can occupy…

Flavonols Modulate ROS in Tomato Guard Cells

Although reactive oxygen species (ROS) have historically been considered damaging agents within cells, recent studies have demonstrated that these molecules also serve as second messengers in signaling pathways. The reactive nature of ROS allows these compounds to function as signaling molecules by reversibly…

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…

Update: Root plasticity and internal aeration

By Takaki Yamauchi, Timothy D Colmer, Ole Pedersen, Mikio Nakazono Introduction Root acquisition of water and nutrients is essential for plant growth and crop productivity (Lynch, 2015). An improved understanding of root system development and functioning, to identify root traits contributing to…

ABA accumulation in dehydrating leaves is associated with decline in cell volume not turgor pressure

Desiccating leaves show increased ABA levels triggered by low turgor – right? Apparently not! The pressure chamber experiments showing increased ABA levels in desiccating leaves are inconsistent when the entire leaves are enclosed in the chamber. Sack et al. proposes that the turgor pressure is increased…