Article
Biotechnology & Applied Microbiology
Tomoya Maeda, Abigail Koch-Koerfges, Michael Bott
Summary: The oxidation of NADH and reduction of quinone is crucial for cellular metabolism. In this study with Corynebacterium glutamicum, Ndh was found to be the main enzyme for NADH oxidation, while Mdh and LdhA can functionally replace Ndh. The study also showed that Mdh and LdhA, along with Mqo and LldD, play active roles in NADH oxidation and menaquinone reduction.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2021)
Review
Plant Sciences
Mingzhu Ma, Yifei Liu, Chunming Bai, Jean Wan Hong Yong
Summary: The Chloroplast NAD(P)H dehydrogenase (NDH) complex, an important alternative electron transport pathway, plays a crucial role in maintaining the redox system balance in plants and providing extra ATP for biochemical reactions. Understanding NDH-mediated cyclic electron transport during photosynthesis may lead to improved crop yield by aiding plants in adapting to environmental stress.
FRONTIERS IN PLANT SCIENCE
(2021)
Article
Biochemistry & Molecular Biology
Alexander T. Eprintsev, Dmitry N. Fedorin, Abir U. Igamberdiev
Summary: This study investigated the expression and methylation of promoters of genes encoding succinate dehydrogenase, fumarase, and NAD-malate dehydrogenase in maize leaves under different light conditions. The expression of succinate dehydrogenase genes was suppressed by red light and restored by far-red light, accompanied by changes in promoter methylation. The expression of fumarase was regulated by red and far-red light through promoter methylation. Only one gene encoding the mitochondrial NAD-malate dehydrogenase was regulated by light, while the other gene was not affected, and both genes were not controlled by promoter methylation.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Biology
Kazusato Oikawa, Takuto Imai, Chonprakun Thagun, Kiminori Toyooka, Takeshi Yoshizumi, Kazuya Ishikawa, Yutaka Kodama, Keiji Numata
Summary: The researchers investigated the rate and trajectory of mitochondria in Arabidopsis thaliana mesophyll cells using confocal laser-scanning microscopy. They discovered that mitochondria migrate through wiggling during their association with chloroplasts, shedding light on the impact of mitochondria-chloroplast interaction on mitochondrial movement.
COMMUNICATIONS BIOLOGY
(2021)
Article
Multidisciplinary Sciences
Yuichi Yokochi, Keisuke Yoshida, Florian Hahn, Atsuko Miyagi, Ken-ichi Wakabayashi, Maki Kawai-Yamada, Andreas P. M. Weber, Toru Hisabori
Summary: The redox regulation of enzyme activity through cysteine residues in chloroplasts is crucial for maintaining NADPH homeostasis under different light conditions. A mutation that eliminates a redox switch in chloroplast NADP-malate dehydrogenase results in severe growth retardation in plants under short-day or fluctuating light conditions, highlighting the importance of fine-tuning the activity of key enzymes for efficient photosynthesis.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Plant Sciences
Abir U. Igamberdiev, Natalia Bykova
Summary: In photosynthetic tissues, chloroplasts are responsible for energy production, while mitochondrial metabolism adjusts to maintain ATP supply and optimize key metabolic fluxes.In the presence of light, the tricarboxylic acid cycle transforms into a noncyclic open structure, supported by the exchange of malate and citrate between chloroplasts and the cytosol. This exchange supports redox energy transfer, contributes to amino acid biosynthesis, and drives secondary metabolism through substrate supply. The coordinated operation of noncoupled mitochondrial respiration and the malate and citrate valves ensures efficient respiration and photorespiration, maintaining redox and energy balance in photosynthetic cells.
Article
Biochemistry & Molecular Biology
Keiko Midorikawa, Keiji Numata, Yutaka Kodama
Summary: The size and shape of organelles can affect biochemical reactions in cells. This study found that the morphologies of peroxisomes varied with proximity to the nucleus, indicating the presence of a nucleus-peroxisome signal transduction cascade mediated by chloroplasts.
Article
Plant Sciences
Jianling Song, Xiaoyan Zou, Pandao Liu, Juan Andres Cardoso, Rainer Schultze-Kraft, Guodao Liu, Lijuan Luo, Zhijian Chen
Summary: The importance of malate dehydrogenase (MDH) in cellular metabolism, redox homeostasis, and response to nutrient and metal stresses in Stylosanthes guianensis (stylo) is demonstrated in this study.
PLANT PHYSIOLOGY AND BIOCHEMISTRY
(2022)
Editorial Material
Cell Biology
Hui Zhang, Qihua Ling
Summary: This article introduces a significant cellular process, autophagy, which degrades unwanted or damaged macromolecules and organelles through the lysosome or vacuole for recycling. Selective autophagy was found to play a crucial role in regulating chloroplast protein import and enhancing stress tolerance in plants.
Article
Plant Sciences
Thomas Waksman, Noriyuki Suetsugu, Pawel Hermanowicz, James Ronald, Stuart Sullivan, Justyna Labuz, John M. Christie
Summary: Directional movements in plants are regulated by the protein RPT2, which is phosphorylated by phot1 and phot2. This phosphorylation is important for leaf positioning, phototropism, and chloroplast accumulation movement, and highlights the significance of the C-terminal region of NRL proteins in phot receptor signaling.
Article
Plant Sciences
Xin Chai, Xiushun Wang, Liwei Rong, Manfei Luo, Li Yuan, Qiuxin Li, Baoye He, Jingjing Jiang, Daili Ji, Min Ouyang, Qingtao Lu, Lixin Zhang, Jean-David Rochaix, Wei Chi
Summary: This study reveals a previously unknown function of the inner envelope membrane-bound AAA-ATPase FtsHi1 in maintaining R-loop homeostasis in chloroplasts of Arabidopsis thaliana. It is shown that FtsHi1 acts as an ATP-dependent helicase and prevents the accumulation of R-loops by unwinding both DNA-DNA and DNA-RNA duplexes. The dual function of FtsHi1 in protein import and chloroplast gene expression suggests a mechanical link between these two processes in higher plant chloroplasts.
Article
Plant Sciences
Maria N. Danilova, Natalia Kudryakova, Anastasia S. Doroshenko, Amina G. Daminova, Ralf Oelmuller, Victor V. Kusnetsov
Summary: The study investigates the role of cytokinin in the senescence process of detached Arabidopsis leaves. It finds that cytokinin inhibits photosynthesis activity and chlorophyll content while promoting anthocyanin accumulation and ROS production. Additionally, cytokinin stimulates starch accumulation and alters the expression of extracellular cell wall enzyme genes.
PLANT GROWTH REGULATION
(2023)
Article
Multidisciplinary Sciences
David Zimmer, Corne Swart, Alexander Graf, Stephanie Arrivault, Michael Tillich, Sebastian Proost, Zoran Nikoloski, Mark Stitt, Ralph Bock, Timo Muehlhaus, Alix Boulouis
Summary: Photosynthetically produced electrons are used to activate Calvin-Benson cycle enzymes and other plastid proteins by reducing specific cysteines via thioredoxins. The redox network in chloroplasts connects the photosynthetic chain with cellular metabolism, allowing fine-tuning of each redox-regulated step. New redox-regulated proteins, involved in Mg2+ transport and signaling, were identified, providing a system-level functional view of the photosynthetic redox regulation network.
Article
Multidisciplinary Sciences
Melissa Bredow, Kyle W. Bender, Alexandra Johnson Dingee, Danalyn R. Holmes, Alysha Thomson, Danielle Ciren, Cailun A. S. Tanney, Katherine E. Dunning, Marco Trujillo, Steven C. Huber, Jacqueline Monaghan
Summary: Phosphorylation of Ser318 is crucial for the activation of CPK28 in immune homeostasis and stem elongation, providing protection against immune response initiation in the absence of infection. In contrast, Ser318 phosphorylation is not necessary for stem elongation, indicating pathway-specific requirements for phosphorylation-based Ca2+-sensitivity priming. This research also suggests a potential biotechnological application in enhancing resistance to microbial pathogens without affecting yield through conserved Ser318 phosphorylation in related group IV CDPKs.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Biochemistry & Molecular Biology
Yumi Eo, Men Thi Hoai Duong, Hee-Chul Ahn
Summary: This study used X-ray crystallography to solve complex structures of hMDH2 with substrates and/or cofactors, providing insights into the molecular and enzymatic mechanism of this enzyme and potential for designing novel inhibitors.