Recent Posts

Back to where it came from: chloroplast expression of both Rubisco subunits helps functional enzyme analysis

Rubisco catalyzes the key carboxylation step in photosynthetic CO2 fixation and is probably the most abundant protein on Earth. The enzyme is famous for inefficient catalysis and the habit of binding oxygen instead of CO2 in one out of every four binding events, leading to photorespiration reactions…

Synthetic conversion of leaf chloroplasts into carotenoid-rich plastids reveals mechanistic basis of natural chromoplast development (PNAS) ($)

Biofortification aims at increasing the content of health-promoting nutrients in edible parts of the plant. As an example, enhancing the production of carotenoids - natural pigments that provide the yellow to red color – in crops could prevent vitamin A deficiency in humans. In nature, carotenoids…

Stimulating photosynthetic processes increases productivity and water-use efficiency in the field (Nature Plants)

Yield potential in crops is determined by the efficiency of photosynthetic rates, which is a critical target for improvement. Previous studies have shown that photosynthetic carbon assimilation and plant biomass can be improved by the stimulation of either regeneration of RuBP (the five-carbon sugar…

Multi-omics reveals mechanisms of total resistance to extreme illumination of a desert alga (Nature Plants)

The green alga Chlorella ohadii was recently isolated from the harsh environment of desert biological sand crusts, where it is able to grow and thrive in extreme conditions. Previously, studies showed that it is unusually resistant to photodamage, even at twice the irradiance of maximal sunlight thanks…

Back to the Future for Plant Rubisco Bioengineering

Martin-Avila et al. use synthetic biology to improve photosynthesis in tobacco by swapping out the endogenous small subunits of Rubisco for one coming from potato, among other things. Plant Cell https://doi.org/10.1105/tpc.20.00288 By Spencer Whitney, Elena Martin-Avila, Sally Buck, Timothy Rhodes,…

Modifying plant photosynthesis and growth via simultaneous chloroplast transformation of Rubisco large and small subunits (Plant Cell)

In an interesting evolutionary artifact, the genes encoding the small subunit of Rubisco, rbcS, reside in the nuclear genome, whilst those encoding RbcL persists in the chloroplast. The RbcS protein is translocated into the chloroplast where the holoenzyme forms. This complexity adds to the challenge…

Plastocyanin is the long-range electron carrier between photosystem II and photosystem I in plants (PNAS)

In linear electron transport (LET), electrons are passed from photosystem II to photosystem I, but it has not been clear which of two mobile electron carriers is responsible, plastocyanin (PC) or plastoquinone (PQ). PQ carries electrons from PSII to the cyt b6f complex and PC from there to PSI. Höhner…

Highly active rubiscos discovered by systematic interrogation of natural sequence diversity (EMBO J)

This is a fascinating and very well-written paper that investigates the diversity of rubisco's kinetic properties. Rubisco’s relationship with its substrate CO2 is complicated by its relationship with O2, and it has often been suggested that for this reason rubisco is locked into a slow rate of catalysis.…

Natural variations at the Stay-Green gene promoter control lifespan and yield in rice cultivars (Nature Comms)

Crop production is greatly influenced by the duration of the last stage of plant life cycle, senescence, through degradation of resources in leaves and remobilization of nutrients to developing seeds. Indeed, higher grain yield of important cereals such as maize and sorghum can be achieved by using stay-green…