C(4) photosynthesis involves alterations to leaf development, cell biology and biochemistry. Different lineages of C(4) plants use varying mechanisms to generate the C(4) pathway. Although the biochemistry of C(4) photosynthesis was described around 20 years ago, the phylogenetic distance between Arabidopsis and the traditional C(4) models has not facilitated the transfer of knowledge from Arab...

Net photosynthetic carbon uptake of Panamanian lowland tropical forest species is typically optimal at 30-32 °C. The processes responsible for the decrease in photosynthesis at higher temperatures are not fully understood for tropical trees. We determined temperature responses of maximum rates of RuBP-carboxylation (VCMax ) and RuBP-regeneration (JMax ), stomatal conductance (Gs ), and respirat...

C4 photosynthesis without Kranz anatomy (single-cell C4 photosynthesis) occurs in only 0.003% of known species of C4 flowering plants. To add insight into the evolution of C4 photosynthesis, we studied the tribe Orcuttieae (Poaceae: Chloridoideae), which has species that can grow under both aquatic and terrestrial conditions, and utilize single-cell C4 photosynthesis when growing submerged. Car...

The small RNA PcrZ (photosynthesis control RNA Z) of the facultative phototrophic bacterium Rhodobacter sphaeroides is induced upon a drop of oxygen tension with similar kinetics to those of genes for components of photosynthetic complexes. High expression of PcrZ depends on PrrA, the response regulator of the PrrB/PrrA two-component system with a central role in redox regulation in R. sphaeroi...

Hybrids have been made between species of Flaveria exhibiting varying levels of C(4) photosynthesis. The degree of C(4) photosynthesis expressed in four interspecific hybrids (Flaveria trinervia [C(4)] x F. linearis [C(3)-C(4)], F. brownii [C(4)-like] x F. linearis, and two three-species hybrids from F. trinervia x [F. brownii x F. linearis]) was estimated by inhibiting phosphoenolpyruvate carb...

The sugars of avocado leaves and leaf disks were labeled by photosynthesis in CO2 during various periods. The label found in the sugars was examined immediately following photosynthesis as well as after a period of respiration under various conditions. Sucrose was found to be the sugar most rapidly labeled during photosynthesis. Mannoheptulose was formed concurrently with sucrose but at a lower...

Previous studies suggest that the radiative effects of atmospheric aerosols (reducing total radiation while increasing the diffuse fraction) can enhance terrestrial productivity. Here, simulations using a regional climate/terrestrial biosphere model suggest that atmospheric aerosols could also enhance terrestrial photosynthesis and transpiration through an interaction between solar radiation, l...

In this Perspective, we discuss current challenges in artificial photosynthesis research, with a focus on the benefits of a nanowire morphology. Matching the flux between electrocatalysts and light-absorbers, and between individual semiconducting light-absorbers, are two major issues to design economically viable devices for artificial photosynthesis. With the knowledge that natural photosynthe...

The responses of respiration and photosynthesis to temperature fluctuations in marine macroalgae have the potential to significantly affect coastal carbon fluxes and sequestration. In this study, the marine red macroalga Gracilaria lemaneiformis was cultured at three different temperatures (12, 19, and 26°C) and at high- and low-nitrogen (N) availability, to investigate the acclimation potentia...

Before the Earth's complete oxygenation (0.58 to 0.55 billion years [Ga] ago), the photic zone of the Proterozoic oceans was probably redox stratified, with a slightly aerobic, nutrient-limited upper layer above a light-limited layer that tended toward euxinia. In such oceans, cyanobacteria capable of both oxygenic and sulfide-driven anoxygenic photosynthesis played a fundamental role in the gl...