Recent Posts

A close-up view of the thylakoids (eLIFE)

The thylakoid membranes inside the chloroplasts house the major protein complexes required for photosynthesis, including photosystems I and II (PSI/II), the b6f complex and ATP synthase. To optimize photosynthetic efficiency, the distribution and abundance of these complexes are dynamically regulated…

Nuclear-encoded synthesis of the D1 subunit of photosystem II increases photosynthetic efficiency and crop yield (Nature Plants)

Photosystem II (PSII) is a protein complex located in the thylakoid membrane of chloroplasts that is involved in executing the initial reaction of photosynthesis in plants. When plants are exposed to extreme temperature conditions, PSII gets damaged. To repair the damage, one of the core proteins of…

How to transfer lipids from one membrane to another during thylakoid biogenesis (PNAS)

The thylakoid membranes are located in the stroma of chloroplasts and house the machinery for the photosynthetic light reactions. They emerge largely de novo during the transition from pro-plastids into mature, photosynthesizing chloroplasts. Generating new thylakoid membranes requires a supply of lipids,…

Mars1 kinase signaling in the chloroplast unfolded protein response (eLIFE)

In stressful situations, such as high light and nutrient scarcity, the chloroplast may experience increased proteotoxicity due to a surge in damaging reactive oxygen species. In response, a signal is sent to the nucleus to increase production of many proteins, including proteases and chaperones to help…

Breaking Water-wise Photosynthesis

Boxall et al. explore the effects of silencing phosphoenolpyruvate carboxylase in a Crassulacean acid metabolism species. Plant Cell https://doi.org/10.1105/tpc.19.00481 By Susie Boxall and James Hartwell Background: Severe droughts and high temperatures are becoming more frequent due to climate…

Structural basis of unidirectional energy transfer in Porphyridium purpureum phycobilisome (Nature)

Cyanobacteria and red algae employ phycobilisomes (PBSs) as light-harvesting systems to adapt to fluctuating environments. PBSs are composed of phycobiliproteins, linker proteins and chromophores. Ma et al. used cryo-EM to determine the 2.82 Å structure of  the very large (14.7-megadalton, 706 protein…

Embryonic photosynthesis affects post-germination plant growth (Plant Physiol.)

Angiosperm seeds develop within maternal tissues, yet in some species including Arabidopsis the developing embryos carry out photosynthesis. In Arabidopsis, this is transitory, and the embryonic chloroplasts lose chlorophyll and dedifferentiate into eoplasts as the seed matures. Sela et al. set out to…

The photosystem factory in chloroplasts

Sun et al. reveal the subcellular organization of photosystem biogenesis in Chlamydomonas. Plant Cell https://doi.org/10.1105/tpc.19.00263 by Melissa Valente-Paterno, Yi Sun and William Zerges. Department of Biology, Concordia University.  Background: Cells localize intracellular processes to…

Special Issue: New perspectives on crassulacean acid metabolism biology

Crassulacean acid metabolism (CAM) is a water-conserving strategy in which stomata open at night and carbon is stored until daytime photosynthesis provides the energy to fix it. This special issue of the Journal of Experimental Botany, edited by Hultine, Cushman, and Williams, brings together a set of…