Article
Biochemistry & Molecular Biology
Qingting Liu, Xiaoping Li, Joerg Fettke
Summary: By using laser confocal scanning microscopy, researchers found that in Arabidopsis mutants with altered starch metabolism, guard cells contained more but smaller plastidial starch granules compared to mesophyll cells. The morphological properties of the starch granules were indiscernible in both types of leaf cells.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Plant Sciences
Sidratul Nur Muntaha, Xiaoping Li, Julia Compart, Ardha Apriyanto, Joerg Fettke
Summary: The Arabidopsis double mutant lacking DPE2 and PHS1 shows a dwarf-growth phenotype, uneven starch distribution, and reduced starch granule number. In contrast, the triple mutant with an additional lack of GWD exhibits improved growth, starch-excess phenotype, and homogeneous starch distribution. Ongoing starch degradation is found to be the main cause of the observed double mutant phenotype.
PLANT PHYSIOLOGY AND BIOCHEMISTRY
(2022)
Article
Plant Sciences
Wenjiao Zou, Kui Liu, Xueping Gao, Changjiang Yu, Xiaofei Wang, Junjie Shi, Yanru Chao, Qian Yu, Gongke Zhou, Lei Ge
Summary: This study reveals altered metabolism of transitory starch in the wxr1/wxr3 mutants of Arabidopsis, shedding light on the important roles of WXR1/WXR3 in plant growth, possibly through regulating ionic equilibrium in the root to promote transitory starch degradation.
JOURNAL OF EXPERIMENTAL BOTANY
(2021)
Review
Biochemistry & Molecular Biology
Ardha Apriyanto, Julia Compart, Joerg Fettke
Summary: Starch is a complex carbohydrate polymer produced by plants and crops. It is essential for nutrition and energy in humans and animals. Nowadays, starch is commonly used in non-food industrial sectors. This review summarizes the structural properties of starch, analytical methods for starch characterization, and in planta starch modifications.
Article
Plant Sciences
Sabrina Flutsch, Daniel Horrer, Diana Santelia
Summary: In this study, we characterized the starch synthesis dynamics in guard cells (GCs) and discovered that GCs have metabolic features of both photoautotrophic and heterotrophic cells. We found that GCs use different carbon precursors to synthesize starch depending on the time of day, which can come from both GC photosynthesis and sugars imported from the leaf mesophyll. We also identified the major enzymes involved in GC starch synthesis and demonstrated their temporal activation according to the fluctuations of stomatal aperture.
Article
Biotechnology & Applied Microbiology
Kanata Hoshino, Ryoko Hamauzu, Hiroyuki Nakagawa, Shinya Kodani, Takeshi Hosaka
Summary: This study investigates the drug resistance selection method for studying secondary metabolites in actinomycetes. Different types of secondary metabolite-overproducing strains were found in ofloxacin-resistant mutants. Additionally, it was observed that some of the mutants overproduced antibiotics in the presence of ofloxacin.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Review
Plant Sciences
Marino B. Arnao, Josefa Hernandez-Ruiz, Antonio Cano, Russel J. Reiter
Summary: Melatonin, a multifunctional molecule present in all living organisms, is synthesized in plant cells in various organelles and plays a role as a modulatory agent improving plant tolerance to stress. This study reviews the effects of melatonin on plant carbohydrate metabolism under stress conditions, evaluating its modulation on various biosynthetic and degradation pathways. Furthermore, potential applications of melatonin in crop improvement and postharvest products are examined.
Article
Biochemistry & Molecular Biology
Yanrong Huang, Sushil Dhital, Feitong Liu, Xiong Fu, Qiang Huang, Bin Zhang
Summary: This study investigated the impact of processing temperature on the structure and permeability of intact cells from pinto beans, leading to changes in the colonic fermentation rate, short-chain fatty acids production, and abundance of beneficial microbiota. The increased cell wall permeability allowed easier access for microbes and/or microbial enzymes to intracellular starch for fermentation, resulting in enhanced metabolite production and beneficial microbe abundance. Controlled processing of whole foods can therefore achieve desired colonic fermentation profiles for improved gut health.
Article
Plant Sciences
Julia Compart, Xiaoping Li, Joerg Fettke
Summary: Starch is a natural storage carbohydrate in plants and algae, consisting of amylopectin and amylose. Despite increasing knowledge, there are still significant gaps in understanding the structure and turnover of starch, especially in relation to biosynthesis, degradation, and its potential for industrial applications.
JOURNAL OF PLANT PHYSIOLOGY
(2021)
Review
Plant Sciences
Michael R. Blatt, Mareike Jezek, Virgilio L. Lew, Adrian Hills
Summary: Stomatal pores enable gaseous exchange between leaf air spaces and the atmosphere, opening for CO2 entry during photosynthesis and closing to minimize water loss. Modeling the response of stomata to the environment has been an area of interest to understand its implications for plants and ecosystems. While models focusing on stomatal conductance make sense, it is important to connect them with the mechanics of guard cells that regulate pore size in order to comprehend the decisions made by stomata and their effects on the plant and global environment.
TRENDS IN PLANT SCIENCE
(2022)
Article
Endocrinology & Metabolism
Jee-Eun Choi, Carlos Sebastian, Christina M. Ferrer, Caroline A. Lewis, Moshe Sade-Feldman, Thomas LaSalle, Anna Gonye, Begona G. C. Lopez, Walid M. Abdelmoula, Michael S. Regan, Murat Cetinbas, Gloria Pascual, Gregory R. Wojtkiewicz, Giorgia G. Silveira, Ruben Boon, Kenneth N. Ross, Itay Tirosh, Srinivas V. Saladi, Leif W. Ellisen, Ruslan I. Sadreyev, Salvador Aznar Benitah, Nathalie Y. R. Agar, Nir Hacohen, Raul Mostoslavsky
Summary: The study highlights the important tumor suppressor role of NAD(+)-dependent histone deacetylase sirtuin 6 in squamous cell carcinoma, as well as the existence of a subset of highly glycolytic tumor-propagating cells with elevated antioxidant capacity. These findings emphasize the key role of metabolism in intra-tumor heterogeneity.
Article
Biochemistry & Molecular Biology
Lucia Piro, Sabrina Flutsch, Diana Santelia
Summary: Research showed that starch in stomatal guard cells is mainly synthesized using carbon precursors from imported sugars. The cytosolic sucrose synthase (SUS) was found to play a role in this process. Among the Arabidopsis SUS gene family, SUS3 was highly expressed in guard cells. The sus3 mutant displayed a similar guard cell starch content to the wild type initially, but later began to accumulate starch at a much higher rate, suggesting that SUS3 regulates carbon fluxes for starch synthesis during the second half of the day.
PLANT SIGNALING & BEHAVIOR
(2023)
Review
Agricultural Engineering
Maria Augusta de Carvalho Silvello, Igor Severo Goncalves, Suellen Patricia Held Azambuja, Sharlene Silva Costa, Pedro Garcia Pereira Silva, Lucielen Oliveira Santos, Rosana Goldbeck
Summary: Microalgae play a significant role in the global carbon cycle through photosynthesis, and their carbohydrates are a promising resource for biofuel production with potential applications. Manipulating cultivation conditions can increase the content of microalgal polysaccharides, enabling their use in producing a variety of biofuels.
BIORESOURCE TECHNOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Anna Laura Voigt, Douglas Andrew Kondro, Diana Powell, Hanna Valli-Pulaski, Mark Ungrin, Jan-Bernd Stukenborg, Claudia Klein, Ian A. Lewis, Kyle E. Orwig, Ina Dobrinski
Summary: This study demonstrates distinct metabolic characteristics and mitochondrial ultrastructure changes in early prepubertal human spermatogonia (gonocytes) compared to mature spermatogonia (SSCs), including metabolic transition, reliance on oxidative phosphorylation (OXPHOS), lactate excretion, and upregulation of uncoupling protein 2 (UCP2) associated with anaerobic metabolism. These differences are accompanied by specific protein expression and pathway activation related to stem cells, indicating unique metabolic demands for gonocytes compared to mature spermatogonia.
Article
Biotechnology & Applied Microbiology
Kevin L. Chu, Somnath Koley, Lauren M. Jenkins, Sally R. Bailey, Shrikaar Kambhampati, Kevin Foley, Jennifer J. Arp, Stewart A. Morley, Kirk J. Czymmek, Philip D. Bates, Doug K. Allen
Summary: The metabolic plasticity of tobacco leaves was demonstrated by generating transgenic plants with high lipid accumulation. Research showed that foliar lipids increased gradually with plant development, while starch content decreased, indicating a metabolic carbon tradeoff between starch and lipids. Additionally, the contribution of NADP-malic enzyme to plastidic pyruvate production for lipid synthesis was highlighted as a key factor in the successful leaf lipid engineering efforts in tobacco.
METABOLIC ENGINEERING
(2022)
Article
Plant Sciences
Tobias Meitzel, Ruslana Radchuk, Erin L. McAdam, Ina Thormaehlen, Regina Feil, Eberhard Munz, Alexander Hilo, Peter Geigenberger, John J. Ross, John E. Lunn, Ljudmilla Borisjuk
Summary: Plants undergo various developmental transitions, including the interaction between sugars and hormones during seed development. By modulating the content of the signaling sugar trehalose 6-phosphate (T6P), the biosynthesis of the key plant hormone auxin can be stimulated, facilitating seed filling processes. This study provides insight into how a metabolic signal like T6P governs hormonal control in crop plants.
Article
Plant Sciences
Franziska Fichtner, Francois F. Barbier, Maria G. Annunziata, Regina Feil, Justyna J. Olas, Bernd Mueller-Roeber, Mark Stitt, Christine A. Beveridge, John E. Lunn
Summary: Tre6P is expressed in axillary buds and vasculature in Arabidopsis, and it plays a role in regulating shoot branching by connecting with systemic regulation via FT. Direct genetic evidence shows that Tre6P has a local role in regulating axillary bud outgrowth within the buds themselves.
Article
Biotechnology & Applied Microbiology
Maria Ermakova, Stephanie Arrivault, Rita Giuliani, Florence Danila, Hugo Alonso-Cantabrana, Daniela Vlad, Hirofumi Ishihara, Regina Feil, Manuela Guenther, Gian Luca Borghi, Sarah Covshoff, Martha Ludwig, Asaph B. Cousins, Jane A. Langdale, Steven Kelly, John E. Lunn, Mark Stitt, Susanne von Caemmerer, Robert T. Furbank
Summary: Introducing a C-4 photosynthetic mechanism into C-3 crops offers the potential to improve photosynthetic efficiency, biomass, and yield, especially in rice. The study showed that with enhanced levels of introduced C-4 proteins, a functional C-4 pathway could be achieved in rice.
PLANT BIOTECHNOLOGY JOURNAL
(2021)
Article
Plant Sciences
Cristina Pignocchi, Alexander Ivakov, Regina Feil, Martin Trick, Marilyn Pike, Trevor L. Wang, John E. Lunn, Alison M. Smith
Summary: It is found that plant roots rely on sucrose imported from leaves for metabolism and growth. Reduced activity of cytosolic invertase leads to metabolic, growth, and developmental defects in Arabidopsis seedling roots. This indicates the importance of sugar signaling for growth and development in plants.
JOURNAL OF EXPERIMENTAL BOTANY
(2021)
Article
Plant Sciences
Zhiyang Zhai, Jantana Keereetaweep, Hui Liu, Regina Feil, John E. Lunn, John Shanklin
Summary: Through heterologous expression of E. coli T6P synthase and phosphatase in transgenic Arabidopsis, fatty acid synthesis can be regulated to increase lipid content in seeds and vegetative tissues. Moreover, otsA expression significantly elevates T6P levels, leading to increased fatty acid synthesis rate and TAG accumulation.
FRONTIERS IN PLANT SCIENCE
(2021)
Article
Plant Sciences
Gian Luca Borghi, Stephanie Arrivault, Manuela Guenther, David Barbosa Medeiros, Emilia Dell'Aversana, Giovanna Marta Fusco, Petronia Carillo, Martha Ludwig, Alisdair R. Fernie, John E. Lunn, Mark Stitt
Summary: Metabolite profiling and (13)CO(2)labelling studies of Flaveria species reveal the progressive re-wiring of various metabolic processes in the evolution from C(3)to C(4)photosynthesis. This includes the relocation of enzymes, establishment of shuttles, and changes in the concentration of organic acids. The findings support current models and provide further insights into the evolutionary path of C(4)photosynthesis in the genus Flaveria.
JOURNAL OF EXPERIMENTAL BOTANY
(2022)
Article
Multidisciplinary Sciences
Harry Klein, Joseph Gallagher, Edgar Demesa-Arevalo, Maria Jazmin Abraham-Juarez, Michelle Heeney, Regina Feil, John E. Lunn, Yuguo Xiao, George Chuck, Clinton Whipple, David Jackson, Madelaine Bartlett
Summary: Research has found that the carpels in maize undergo programmed cell death in specific parts of the inflorescence. The GT1 and RA3 genes play important roles in regulating this process, and their proteins co-localize in the developing floral carpels. Global expression analysis of single and double mutant flowers revealed common misregulation of genes. Additionally, RA3 enhances the branching role of GT1 in plants.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Plant Sciences
Omri Avidan, Thiago A. Moraes, Virginie Mengin, Regina Feil, Filip Rolland, Mark Stitt, John E. Lunn
Summary: Sucrose-nonfermenting 1 (SNF1)-related kinase 1 (SnRK1) is a central hub in carbon and energy signaling in plants, with orthologues in yeast (SNF1) and animals (AMP-activated protein kinase, AMPK). Previous studies focused on in vitro assays or marker gene expression, providing limited information about in vivo SnRK1 activity. This study used Arabidopsis reporter lines to monitor in vivo SnRK1 activity and found that it increased towards the end of the night and further when the night was extended. Surprisingly, SnRK1 activity did not decline until about 12 hours into the light period, despite the rise in sugars after dawn. The metabolite trehalose 6-phosphate (Tre6P), which inhibits SnRK1 in vitro, was introduced into the plants, and it was found that elevated Tre6P decreased SnRK1 activity during the light period. These findings suggest that SnRK1 operates within a network that controls carbon utilization and diel sugar homeostasis, and its activity is regulated by Tre6P in a context-dependent manner.
Editorial Material
Plant Sciences
John E. Lunn
Summary: The Journal of Experimental Botany has appointed six early career researchers as editorial interns to train the next generation of editors.
JOURNAL OF EXPERIMENTAL BOTANY
(2023)
Article
Biochemistry & Molecular Biology
Mickael Durand, Virginie Brehaut, Gilles Clement, Zsolt Kelemen, Julien Mace, Regina Feil, Garry Duville, Alexandra Launay-Avon, Christine Paysant-Le Roux, John E. Lunn, Francois Roudier, Anne Krapp
Summary: Nitrate signaling is crucial for plant growth under limited nitrate availability and NLP2 and NLP7 are key transcriptional regulators that coordinate the nitrate response by regulating carbon and energy metabolism.
Article
Plant Sciences
Itay Zemach, Saleh Alseekh, Roni Tadmor-Levi, Josef Fisher, Shai Torgeman, Shay Trigerman, Julia Nauen, Shdema Filler Hayut, Varda Mann, Edan Rochsar, Richard Finkers, Regina Wendenburg, Sonia Osorio, Susan Bergmann, John E. Lunn, Yaniv Semel, Joseph Hirschberg, Alisdair R. Fernie, Dani Zamir
Summary: By using a phenotype-guided screen of over 7900 tomato accessions, new associations for complex traits such as fruit weight and total soluble solids were identified. The study presented phenotypic data from several years of trials and demonstrated the power of the dataset through two case studies. Genome-wide association analysis allowed the detection of novel loci associated with total soluble solid content and fruit weight, suggesting the usefulness of a phenotype-guided pre-selection strategy for finding target genes for breeding.
Article
Biology
Waeil Al Youssef, Regina Feil, Maureen Saint-Sorny, Xenie Johnson, John E. Lunn, Bernhard Grimm, Pawel Brzezowski
Summary: Using a mutant screen, the functional enzyme trehalose 6-phosphate phosphatase 1 (TSPP1) was identified as responsible for dephosphorylating trehalose 6-phosphate (Tre6P) in Chlamydomonas reinhardtii. Knocking out the tspp1 gene results in reprogramming of cell metabolism and impairment of O-1(2)-induced chloroplast retrograde signalling. Transcriptomic analysis and metabolite profiling indicate that the accumulation or deficiency of certain metabolites directly affect the O-1(2)-signalling process.
COMMUNICATIONS BIOLOGY
(2023)
Editorial Material
Plant Sciences
Donald R. Ort, John E. Lunn
JOURNAL OF EXPERIMENTAL BOTANY
(2023)
Article
Plant Sciences
Hirofumi Ishihara, Saleh Alseekh, Regina Feil, Pumi Perera, Gavin M. George, Piotr Niedzwiecki, Stephanie Arrivault, Samuel C. Zeeman, Alisdair R. Fernie, John E. Lunn, Alison M. Smith, Mark Stitt
Summary: The degradation of starch in the light is regulated by mechanisms similar to those operating at night. The rate of degradation depends on the time relative to dawn rather than dusk. Trehalose 6-phosphate inhibits degradation in the light. Starch degradation in the light plays an important role in stabilizing carbon availability and signaling, optimizing plant growth in natural light conditions.
Article
Plant Sciences
Maximilian M. F. F. Funfgeld, Wei Wang, Hirofumi Ishihara, Stephanie Arrivault, Regina Feil, Alison M. Smith, Mark Stitt, John E. Lunn, Totte Niittyla
Summary: Through re-examination of experimental data, the study shows that starch synthesis in leaves primarily relies on ADPG pyrophosphorylase in chloroplasts, while sucrose synthase in the cytosol makes no substantial contribution to transitory starch synthesis in Arabidopsis leaves. This finding resolves a long-standing controversy in photosynthetic metabolism.
