Over-expression of the CHS gene enhances resistance of Arabidopsis leaves to high light

Previous studies have suggested that high light (HL) stress causes photoinhibition in plants, while anthocyanins could protect the photosynthetic apparatus against photoinhibition. However, the photoprotection mechanism of anthocyanins is still ambiguous. We studied physiological responses and molecular changes for CHS-overexpression lines (CHS1, CHS2, CHS3), Arabidopsis thaliana ecotype Columbia (Col), and T-DNA insertion lines of CHS (tt4) under HL (200 μmol m−2 s−1) to explore the photoprotection mechanism of anthocyanins. The results showed that HL induced anthocyanin synthesis and accumulation. The leaves of CHS-overexpression lines turned reddest and the genes, including CHS, DFR, ANS, were expressed at highest levels. Thus, the CHS-overexpression lines maintained the highest photosynthetic capacity and suffered the least damage from HL of the three phenotypes. However, the CHS enzyme and anthocyanins were undetectable in tt4 during the experiment. Correspondingly, chlorophyll fluorescence parameters of tt4 declined greatly. The photosynthetic apparatus and cell membranes were also impaired dramatically. The physiological characteristics of Col were compared between CHS-overexpression lines and tt4. Together, the results suggest that over-expression of CHS gene enhances HL resistance by synthesizing more anthocyanins, that anthocyanins enhance the adaptability of plants to HL and that they maintain photosynthetic capacity via both antioxidation and attenuation of light.This work was funded by the National Key R&D Program of China (2017YFC1200105) and Guangdong Province Natural Science Foundation (2017A030313167, 2015A030311023). The study was also supported by the National Natural Science Foundation of China (31570398), Science and Technology Program of Guangzhou (20170701257) and Yang Cheng Scholar Program (10A040G)

Blockage of NOX2/MAPK/NF- κ

Acute energy failure is one of the critical factors contributing to the pathogenic mechanisms of retinal ischemia. Our previous study demonstrated that glucose deprivation can lead to a caspase-dependent cell death of photoreceptors. The aim of this study was to decipher the upstream signal pathway in glucose deprivation- (GD-) induced cell death. We mimicked acute energy failure by using glucose deprivation in photoreceptor cells (661W cells). GD-induced oxidative stress was evaluated by measuring ROS with the DCFH-DA assay and HO-1 expression by Western blot analysis. The activation of NOX2/MAPK/NF-κB signal was assessed by Western blot and immunohistochemical assays. The roles of these signals in GD-induced cell death were measured by using their specific inhibitors. Inhibition of Rac-1 and NOX2 suppressed GD-induced oxidative stress and protected photoreceptors against GD-induced cell death. NOX2 was an upstream signal in the caspase-dependent cell death cascade, yet the downstream MAPK pathways were activated and blocking MAPK signals rescued 661W cells from GD-induced death. In addition, GD caused the activation of NF-κB signal and inhibiting NF-κB significantly protected 661W cells. These observations may provide insights for treating retinal ischemic diseases and protecting retinal neurons from ischemia-induced cell death

Intracellular interferons in fish : a unique means to combat viral infection

Peer reviewedPublisher PD

Mastering Complex Control in MOBA Games with Deep Reinforcement Learning

We study the reinforcement learning problem of complex action control in the Multi-player Online Battle Arena (MOBA) 1v1 games. This problem involves far more complicated state and action spaces than those of traditional 1v1 games, such as Go and Atari series, which makes it very difficult to search any policies with human-level performance. In this paper, we present a deep reinforcement learning framework to tackle this problem from the perspectives of both system and algorithm. Our system is of low coupling and high scalability, which enables efficient explorations at large scale. Our algorithm includes several novel strategies, including control dependency decoupling, action mask, target attention, and dual-clip PPO, with which our proposed actor-critic network can be effectively trained in our system. Tested on the MOBA game Honor of Kings, our AI agent, called Tencent Solo, can defeat top professional human players in full 1v1 games.Comment: AAAI 202