Recent Posts

A novel GUN1-independent retrograde signaling pathway represses photomorphogenesis (Plant Physiol.)

Seedlings emerging in light undergo photomorphogenic development, forming short hypocotyls and green, fully opened cotyledons. Disruption of chloroplast development by drugs such as lincomycin induces retrograde signals (RS) that inhibit photomorphogenesis. The retrograde signaling pathway has been known…

More than photosynthesis: The chloroplast’s role in plant cell defense pathways ($) (Cell)

Chloroplasts are involved in various plant cell functions outside of photosynthesis including defense activation. How is the chloroplast able to do so? In this study, Medina-Puche et al. characterized the molecular function and cellular localization of the Tomato yellow leaf curl virus-derived C4 protein.…

Plastid stress signaling alters cell cycle progression (Cell Reports)

The chloroplast is in constant communication with the nucleus via so-called retrograde signaling. This signaling, which can take many molecular forms, is important for maintaining chloroplast function. In this paper by Duan et al. we learn that interfering with plastid DNA replication, either through…

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…

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,…

A natural variant of ORANGE interacts with plastid division factor ARC3 to regulate chromoplast number and carotenoid accumulation (Mol. Plant)

Some “superfoods” have high nutritional value due to the presence of carotenoids, which prevent degenerative diseases like cancer. In plants, these pigments are biosynthesized and stored by plastid organelles called chromoplasts. Chromoplast number and size define total carotenoid accumulation. ORHis,…

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…

Synthetic biogenesis of chromoplasts from leaf chloroplasts (bioRxiv)

Chromoplasts are a type of plastid, usually found in fruits and flowers, that can accumulate large amounts of carotenoids including beta-carotene (pro-vitamin A). It has been proposed that increasing chromoplast formation could be a way to enhance human consumption of vitamin A. In a new report, Llorente…