Green solvent-treated organic solar cells (OSCs) have demonstrated significant strengths in terms of commercialization in recent years. However, the low solubility and high boiling point of green solvents cause difficulties...

Glycine-rich proteins (GRPs) are a large family of proteins that play vital roles in cell wall remodeling, metabolism and development, and abiotic stress response. Although the functions of GRPs in cell wall remodeling have been extensively characterized, only a few studies have explored their effects on chlorophyll metabolism and hormone response. Accordingly, we aimed to determine the molecular mechanism of BcGRP23 and its role in chlorophyll metabolism and the BRI1-EMS-SUPPRESSOR 1 (BES1) signaling pathway in flowering Chinese cabbage. The expression levels of BcGRP23 in the leaves and stems gradually decreased with increasing growth and development of flowering Chinese cabbage, while BcGRP23 was barely expressed after flowering. As plant growth continued, the GUS (β-glucuronidase) stain gradually became lighter in hypocotyls and was largely free of growth points. The petioles and stems of BcGRP23-silenced plants lost their green color, and the contents of chlorophyll a (Chl a) and Chl b were significantly reduced. Further research revealed that the expression levels of chlorophyll degradation-related genes were significantly increased in silenced plants compared with the control; however, the opposite was noted for the BcGRP23-overexpressing lines. The BcGRP23 promoter sequence contains numerous hormone-responsive elements. In fact, the expression of BcGRP23 was upregulated in flowering Chinese cabbage following treatment with the hormones indole-3-acetic acid (IAA), gibberellin (GA), 6-benzylaminopurine (6-BA), methyl jasmonate (MeJA), and brassinosteroid (BR). Treatment with BR led to the most significant upregulation. BES1, in response to BRs, directly activated the BcGRP23 promoter. Overall, BcGRP23 regulated the expression of chlorophyll degradation-related genes, thereby affecting the chlorophyll content. Furthermore, the expression of BcGRP23 was significantly regulated by exogenous BR application and was directly activated by BES1. These findings preliminarily suggest the molecular mechanism and regulatory pathway of BcGRP23 in the growth and development of flowering Chinese cabbage plants and their response to environmental stress.

Reactive oxygen species (ROS) play an important role in sensing the redox pressure involved in the electron transfer chains of photosynthesis. However, due to variation in light, ROS accumulation originated from the excess electrons on the acceptor side of photosystem I gives rise to critical inhibition of photosynthetic carbon fixation. How to regulate the extent to which ROS decrease stimulates energy and metabolic fluxes beyond nature must be known to improve CO 2 fixation. Herein, we report a strategy to deliver biocompatible gold nanoparticles into cyanobacterium Synechocystis sp. PCC 6803 to dispatch the photosynthetic electron hub for improving CO 2 fixation. Biomass of the cyanobacteria increases to 1.6 times with intracellular Au nanoparticles. The enzyme-like gold nanoparticles quench 30% ROS from flavodiiron proteins Flv and increase 21% apparent oxygen evolution, boosting the enzymatic activity of glyceraldehyde 3-phosphate dehydrogenase by an increase of 40% under high light stress. In comparison, gold nanoparticles have no obvious effect on the photosynthetic carbon fixation of the Flv-deficient strain because of severe photoinhibition of photosystems. This intracellular biohybrid strategy for intervention and modulation of complex photosynthetic electron transfer provides new insight into energy conversion and CO 2 fixation of photosynthesis.

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