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1.
J Genet Genomics ; 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38734136

RESUMEN

Crop phenomics enables collection of diverse plant traits for a large number of samples along different time scales, representing a greater data collection throughput compared to the traditional measurements. Most of modern crop phenomics use different sensors to collect reflective, emitted and fluorescence signals etc., from plant organs at different spatial and temporal resolutions. Such multi-modal, high dimensional data not only accelerates basic research on crop physiology, genetics, and whole plant systems modeling, but also supports the optimization of field agronomic practices, internal environments of plant factories, and ultimately crop breeding. Major challenges and opportunities facing the current crop phenomics research community include developing community consensus or standards for data collection, management, sharing, and processing, developing capabilities to measure physiological parameters, and enabling farmers and breeders to effectively use phenomics in the field to directly support agricultural production.

2.
Plant Cell ; 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38701340

RESUMEN

Improving photosynthesis, the fundamental process by which plants convert light energy into chemical energy, is a key area of research with great potential for enhancing sustainable agricultural productivity and addressing global food security challenges. This perspective delves into the latest advancements and approaches aimed at optimizing photosynthetic efficiency. Our discussion encompasses the entire process, beginning with light harvesting and its regulation and progressing through the bottleneck of electron transfer. We then delve into the carbon reactions of photosynthesis, focusing on strategies targeting the enzymes of the Calvin-Benson-Bassham (CBB) cycle. Additionally, we explore methods to increase CO2 concentration near the Rubisco, the enzyme responsible for the first step of CBB cycle, drawing inspiration from various photosynthetic organisms, and conclude this section by examining ways to enhance CO2 delivery into leaves. Moving beyond individual processes, we discuss two approaches to identifying key targets for photosynthesis improvement: systems modeling and the study of natural variation. Finally, we revisit some of the strategies mentioned above to provide a holistic view of the improvements, analyzing their impact on nitrogen use efficiency and on canopy photosynthesis.

3.
Dig Liver Dis ; 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38744556

RESUMEN

OBJECTIVE: The primary purpose of the study was to explore the clinical efficacy of the novel snare assisted endoscopic resection of extraluminal growing gastric gastrointestinal stromal tumors (gastric GISTs) using external traction, and the secondary purpose was to compare the novel snare assisted endoscopic resection of extraluminal GISTs with the standard laparoscopic procedure. METHODS: We retrospectively analyzed the patients who underwent novel external traction assisted endoscopic resection or laparoscopic resection for their extraluminal gastric GIST ≤5 cm in diameter. RESULTS: A total of 111 patients (27 in the endoscopic group and 84 in the laparoscopic group) were included in this study. There was no significant difference in tumor diameter and complication rate between the two groups. The overall procedure time was slightly higher in the endoscopic group compared to the laparoscopic group (P = 0.034). However, postoperative hospitalization time (P < 0.001) and postoperative fasting time (P = 0.005) were shorter in the endoscopic group compared to the laparoscopic group. CONCLUSION: Snare external traction-assisted endoscopic resection of extraluminal growing gastric GISTs is safe and effective, and it provides a new adjunctive method for endoscopic resection of GIST.

4.
Int J Mol Sci ; 25(7)2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38612598

RESUMEN

Severe acute pancreatitis (SAP), a widespread inflammatory condition impacting the abdomen with a high mortality rate, poses challenges due to its unclear pathogenesis and the absence of effective treatment options. Isorhamnetin (ISO), a naturally occurring flavonoid, demonstrates robust antioxidant and anti-inflammatory properties intricately linked to the modulation of mitochondrial function. However, the specific protective impact of ISO on SAP remains to be fully elucidated. In this study, we demonstrated that ISO treatment significantly alleviated pancreatic damage and reduced serum lipase and amylase levels in the mouse model of SAP induced by sodium taurocholate (STC) or L-arginine. Utilizing an in vitro SAP cell model, we found that ISO co-administration markedly prevented STC-induced pancreatic acinar cell necrosis, primarily by inhibiting mitochondrial ROS generation, preserving ATP production, maintaining mitochondrial membrane potential, and preventing the oxidative damage and release of mitochondrial DNA. Mechanistically, our investigation identified that high-temperature requirement A2 (HtrA2) may play a central regulatory role in mediating the protective effect of ISO on mitochondrial dysfunction in STC-injured acinar cells. Furthermore, through an integrated approach involving bioinformatics analysis, molecular docking analysis, and experimental validation, we uncovered that ISO may directly impede the histone demethylation activity of KDM5B, leading to the restoration of pancreatic HtrA2 expression and thereby preserving mitochondrial function in pancreatic acinar cells following STC treatment. In conclusion, this study not only sheds new light on the intricate molecular complexities associated with mitochondrial dysfunction during the progression of SAP but also underscores the promising value of ISO as a natural therapeutic option for SAP.


Asunto(s)
Enfermedades Mitocondriales , Pancreatitis , Quercetina/análogos & derivados , Animales , Ratones , Pancreatitis/tratamiento farmacológico , Enfermedad Aguda , Simulación del Acoplamiento Molecular , Mitocondrias , Transducción de Señal
5.
Methods Mol Biol ; 2790: 213-226, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38649573

RESUMEN

Canopy photosynthesis (Ac), rather than leaf photosynthesis, is critical to gaining higher biomass production in the field because the daily or seasonal integrals of Ac correlate with the daily or seasonal integrals of biomass production. The canopy photosynthesis and transpiration measurement system (CAPTS) was developed to enable measurement of canopy photosynthetic CO2 uptake, transpiration, and respiration rates. CAPTS continuously records the CO2 concentration, water vapor concentration, air temperature, air pressure, air relative humidity, and photosynthetic photon flux density (PPFD) inside the chamber, which can be used to derive CO2 and H2O fluxes of a canopy covered by the chamber. This system can also be used to measure the fluxes of greenhouse gases when integrating with CH4 and N2O analyzers. Here, we describe the protocol for using CAPTS to perform experiments on rice (Oryza sativa L.) in paddy field, wheat (Triticum aestivum L.) in upland field, and tobacco (Nicotiana tabacum L.) in pots.


Asunto(s)
Dióxido de Carbono , Oryza , Fotosíntesis , Hojas de la Planta , Transpiración de Plantas , Fotosíntesis/fisiología , Transpiración de Plantas/fisiología , Dióxido de Carbono/metabolismo , Dióxido de Carbono/análisis , Oryza/crecimiento & desarrollo , Oryza/fisiología , Oryza/metabolismo , Hojas de la Planta/fisiología , Hojas de la Planta/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Nicotiana/fisiología , Nicotiana/metabolismo , Nicotiana/crecimiento & desarrollo , Triticum/crecimiento & desarrollo , Triticum/fisiología , Triticum/metabolismo , Agua/metabolismo
6.
J Sci Food Agric ; 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38597282

RESUMEN

BACKGROUND: Peach gum (PG) is an exudate of the peach tree (Prunus persica of the Rosaceae family), which consists primarily of polysaccharides with a large molecular weight and branching structure. Consequently, PG can only swell in water and does not dissolve easily, which severely limits its application. Current conventional extraction methods for PG polysaccharide (PGPS) are time consuming and inefficient. This study investigated the impact of ultrasonic-assisted extraction (UAE) on PGPS structure and conformation, and their relationship to hypoglycemic activity in vitro. RESULTS: In comparison with conventional aqueous extraction, UAE enhanced PGPS yielded from 28.07-32.83% to 80.37-84.90% (w/w) in 2 h. It drastically decreased the molecular size and conformational parameters of PGPS, including weight-average molecular weight (Mw), number-average molecular weight (Mn), z-average radius of gyration (Rg), hydrodynamic radius (Rh) and instrinsic viscosity ([η]) values. Peach gum polysaccharide conformation converted extended molecules to flexible random coil chains or compact spheres with no obvious primary structure alteration. Furthermore, UAE altered the flow behavior of PGPS solution from that of a non-Newtonian fluid to that of a Newtonian fluid. As a result, PGPS treated with UAE displayed weaker inhibitory activity than untreated PGPS, mostly because UAE weakens the binding strength of PGPS to α-glucosidase. However, this negative effect of UAE on PGPS activity was compensated by the increased solubility of polysaccharide. This enabled PGPS to achieve a wider range of doses. CONCLUSION: Ultrasonic-assisted extraction is capable of degrading PGPS efficiently while preserving its primary structure, resulting in a Newtonian fluid solution. The degraded PGPS conformations displayed a consistent correlation with their inhibitory effect on α-glucosidase activity. © 2024 Society of Chemical Industry.

7.
Brain Res ; 1836: 148956, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38657888

RESUMEN

Recent advancements in neuroimaging have illustrated that anterior cruciate ligament (ACL) injuries could impact the central nervous system (CNS), causing neuroplastic changes in the brain beyond the traditionally understood biomechanical consequences. While most of previous functional magnetic resonance imaging (fMRI) studies have focused on localized cortical activity changes post-injury, emerging research has suggested disruptions in functional connectivity across the brain. However, these prior investigations, albeit pioneering, have been constrained by two limitations: a reliance on small-sample participant cohorts, often limited to two to three patients, potentially limiting the generalizability of findings, and an adherence to region of interest based analysis, which may overlook broader network interactions. To address these limitations, our study employed resting-state fMRI to assess whole-brain functional connectivity in 15 ACL-injured patients, comparing them to matched controls using two distinct network analysis methods. Using Network-Based Statistics, we identified widespread reductions in connectivity that spanned across multiple brain regions. Further modular connectivity analysis showed significant decreases in inter-modular connectivity between the sensorimotor and cerebellar modules, and intra-modular connectivity within the default-mode network in ACL-injured patients. Our results thus highlight a shift from localized disruptions to network-wide dysfunctions, suggesting that ACL injuries induce widespread CNS changes. This enhanced understanding has the potential to stimulate the development of strategies aiming to restore functional connectivity and improve recovery outcomes.

8.
Bioorg Chem ; 146: 107286, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38537336

RESUMEN

Pulmonary fibrosis (PF) poses a significant challenge with limited treatment options and a high mortality rate of approximately 45 %. Qingkailing Granule (QKL), derived from the Angong Niuhuang Pill, shows promise in addressing pulmonary conditions. Using a comprehensive approach, combining network pharmacology analysis with experimental validation, this study explores the therapeutic effects and mechanisms of QKL against PF for the first time. In vivo, QKL reduced collagen deposition and suppressed proinflammatory cytokines in a bleomycin-induced PF mouse model. In vitro studies demonstrated QKL's efficacy in protecting cells from bleomycin-induced injury and reducing collagen accumulation and cell migration in TGF-ß1-induced pulmonary fibrosis cell models. Network pharmacology analysis revealed potential mechanisms, confirmed by western blotting, involving the modulation of PI3K/AKT and SRC/STAT3 signaling pathways. Molecular docking simulations highlighted interactions between QKL's active compounds and key proteins, showing inhibitory effects on epithelial damage and fibrosis. Collectively, these findings underscore the therapeutic potential of QKL in alleviating pulmonary inflammation and fibrosis through the downregulation of PI3K/AKT and SRC/STAT3 signaling pathways, with a pivotal role attributed to its active compounds.


Asunto(s)
Medicamentos Herbarios Chinos , Fibrosis Pulmonar , Ratones , Animales , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/tratamiento farmacológico , Fibrosis Pulmonar/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Simulación del Acoplamiento Molecular , Transducción de Señal , Colágeno/metabolismo , Colágeno/farmacología , Colágeno/uso terapéutico , Fibrosis , Bleomicina/efectos adversos
10.
Toxicol Appl Pharmacol ; 484: 116871, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38423217

RESUMEN

Salvia miltiorrhiza Bunge. (DS), as an important traditional Chinese medicine (TCM), has a long history of usage for promoting blood circulation and removing blood stasis. Modern studies have shown that the chemical components of DS have many biological activities such as cardiovascular protection, anti-arrhythmia, anti-atherosclerosis, improvement of microcirculation, protection of myocardium, inhibition and removal of platelet aggregation. Nevertheless, the action mechanism of DS as well its active compounds on platelet activation has not been fully uncovered. This study aimed to find out the potential targets and mechanisms of DS in the modulation of platelet activation and thrombosis, using network pharmacology and biological experimental. These compounds with anti-thrombotic activity in DS, cryptotanshinone (CPT), isoeugenol (ISO) and tanshinone IIA (TSA), together with the corresponding targets being Src, Akt and RhoA are screened by network pharmacology. We confirmed that ISO, CPT and TSA dose-dependently inhibited platelet activation in vitro, mainly by inhibiting agonist-induced clot retraction, aggregation and P-selectin and ATP release. The western blot findings indicated that ISO, CPT, and TSA led to reduced levels of p-Akt and p-ERK in activated platelets. Additionally, ISO and TSA were observed to decrease p-cSrc expression while increasing RhoA expression. ISO, CPT, and TSA demonstrated a potential to restrict the advancement of carotid arterial thrombosis in vivo. We confirm that ISO, CPT and TSA are the key anti-thrombotic active compounds in DS. These active compounds exhibit unique inhibitory effects on platelet activation and thrombus formation by modulating the Akt/ERK and cSrc/RhoA signaling pathways.


Asunto(s)
Salvia miltiorrhiza , Trombosis , Salvia miltiorrhiza/química , Farmacología en Red , Proteínas Proto-Oncogénicas c-akt/farmacología , Activación Plaquetaria , Trombosis/tratamiento farmacológico
11.
Plant Physiol ; 195(1): 291-305, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38377473

RESUMEN

As a complex trait, C4 photosynthesis has multiple independent origins in evolution. Phylogenetic evidence and theoretical analysis suggest that C2 photosynthesis, which is driven by glycine decarboxylation in the bundle sheath cell, may function as a bridge from C3 to C4 photosynthesis. However, the exact molecular mechanism underlying the transition between C2 photosynthesis to C4 photosynthesis remains elusive. Here, we provide evidence suggesting a role of higher α-ketoglutarate (AKG) concentration during this transition. Metabolomic data of 12 Flaveria species, including multiple photosynthetic types, show that AKG concentration initially increased in the C3-C4 intermediate with a further increase in C4 species. Petiole feeding of AKG increases the concentrations of C4-related metabolites in C3-C4 and C4 species but not the activity of C4-related enzymes. Sequence analysis shows that glutamate synthase (Fd-GOGAT), which catalyzes the generation of glutamate using AKG, was under strong positive selection during the evolution of C4 photosynthesis. Simulations with a constraint-based model for C3-C4 intermediate further show that decreasing the activity of Fd-GOGAT facilitated the transition from a C2-dominant to a C4-dominant CO2 concentrating mechanism. All these results provide insight into the mechanistic switch from C3-C4 intermediate to C4 photosynthesis.


Asunto(s)
Flaveria , Ácidos Cetoglutáricos , Fotosíntesis , Fotosíntesis/genética , Ácidos Cetoglutáricos/metabolismo , Flaveria/genética , Flaveria/metabolismo , Filogenia , Carbono/metabolismo , Dióxido de Carbono/metabolismo
12.
Pak J Med Sci ; 40(3Part-II): 467-472, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38356806

RESUMEN

Objective: To explore the changes of serum-related indexes at different time points, so as to identify the critical time of converting from simple premature thelarche (PT) to idiopathic central precocious puberty (ICPP). Methods: This is a retrospective study. The subjects of the study were 50 girls with PT who were admitted to the Children's Hospital of Hebei Province from January 2019 to September 2020. The enrolled 50 children were divided into the conversion group(n=12) and the non-conversion group(n=38) according to whether PT was converted into ICPP during follow-up. Furthermore, the levels of serum-related indexes and uterine and ovarian volumes were compared after the diagnosis of PT. Results: The IGF-1 and IGFBP-3 levels of children in the conversion group began to change significantly from six months after the diagnosis, with statistically significant differences when compared with the levels of children at the initial diagnosis, three months and those of the non-conversion group at the same time points (p<0.05). The levels of vitamin-D, DHEA and leptin began to change significantly at nine months after the diagnosis (p<0.05). Besides, uterine and ovarian volumes in the conversion group began to increase significantly six months after the diagnosis, with statistically significant differences when compared with those in the non-conversion group (p<0.05). Conclusion: Findings in our study suggest that regular monitoring of vitamin-D, IGF-1, IGFBP-3, DHEA and leptin levels, and uterine and ovarian volumes can predict the conversion from PT to ICPP at an early stage.

14.
Plant Physiol ; 194(4): 2400-2421, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38180123

RESUMEN

Light-induced de-etiolation is an important aspect of seedling photomorphogenesis. GOLDEN2 LIKE (GLK) transcriptional regulators are involved in chloroplast development, but to what extent they participate in photomorphogenesis is not clear. Here, we show that ELONGATED HYPOCOTYL5 (HY5) binds to GLK promoters to activate their expression, and also interacts with GLK proteins in Arabidopsis (Arabidopsis thaliana). The chlorophyll content in the de-etiolating Arabidopsis seedlings of the hy5 glk2 double mutants was lower than that in the hy5 single mutant. GLKs inhibited hypocotyl elongation, and the phenotype could superimpose on the hy5 phenotype. Correspondingly, GLK2 regulated the expression of photosynthesis and cell elongation genes partially independent of HY5. Before exposure to light, DE-ETIOLATED 1 (DET1) affected accumulation of GLK proteins. The enhanced etioplast development and photosystem gene expression observed in the det1 mutant were attenuated in the det1 glk2 double mutant. Our study reveals that GLKs act downstream of HY5, or additive to HY5, and are likely quantitatively adjusted by DET1, to orchestrate multiple developmental traits during the light-induced skotomorphogenesis-to-photomorphogenesis transition in Arabidopsis.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Regulación de la Expresión Génica de las Plantas , Hipocótilo , Luz , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Plantones/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
15.
World Neurosurg ; 181: e75-e83, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37532021

RESUMEN

BACKGROUND: Treatment modalities of ependymoma in infants remain controversial. Postoperative adjuvant radiotherapy could prolong overall survival but has the potential to affect nervous system development in infants. The role of adjuvant chemotherapy in prolonging overall survival for infants with ependymoma is still unclear. Therefore we designed this study to explore the effect of treatment modalities on survival time of infants with ependymoma. METHODS: We studied 72 infants with ependymoma from the Surveillance, Epidemiology, and End Results database in this retrospective analysis. Univariate and multivariate Cox proportional hazard models were adopted to determine hazard ratios and compare overall survival. RESULTS: Among 72 infants with ependymoma, 35 were male (48.6%) and 37 were female (51.4%). The 5-year overall survival of all patients was 67%. Forty-six infants (63.9%) received gross total resection, 20 (27.8%) received subtotal resection, and 6 (8.3%) did not receive surgical resection or only autopsy. Twenty-one infants (29.2%) received radiotherapy, and 45 (62.5%) received chemotherapy. Multivariate analysis revealed that patients accepted surgical resection (No vs. gross total resection, P < 0.001; No vs. subtotal resection, P = 0.026) and chemotherapy (No vs. Yes, P = 0.024) are the independent prognostic factors for overall survival. CONCLUSIONS: Treatment modality is associated with survival time in infants with ependymoma. The extent of resection and chemotherapy were independent prognostic factors for infants with ependymoma.


Asunto(s)
Neoplasias Encefálicas , Ependimoma , Lactante , Humanos , Masculino , Femenino , Estudios Retrospectivos , Radioterapia Adyuvante/métodos , Terapia Combinada , Quimioterapia Adyuvante , Resultado del Tratamiento , Neoplasias Encefálicas/terapia
16.
Food Chem ; 438: 137993, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-37992603

RESUMEN

Aroma is one of the decisive factors affecting the quality and consumer acceptance of edible mushrooms. This review summarized the key components and formation pathways of edible mushroom aroma. It also elaborated on the affecting factors and emerging analytical strategies of edible mushroom aroma. A total of 1308 volatile organic compounds identified in edible mushrooms, 61 were key components. The formation of these compounds is closely related to fatty acid metabolism, amino acid metabolism, lentinic acid metabolism, and terpenoid metabolism. The aroma profiles of edible mushrooms were affected by genetic background, preharvest factors, and preservation methods. Molecular sensory science and omics techniques are emerging analytical strategies to reveal aroma information of edible mushrooms. This review would provide valuable data and insights for future research on edible mushroom aroma.


Asunto(s)
Agaricales , Compuestos Orgánicos Volátiles , Agaricales/química , Odorantes , Vías Biosintéticas , Compuestos Orgánicos Volátiles/química , Metabolismo de los Lípidos
17.
Food Res Int ; 175: 113790, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38129010

RESUMEN

To increase the anti-digestion ability of extruded rice starch (ERS), the influence of rice glutelin (RG) on digestive and structural characteristics of ERS were investigated. The resistant starch content increased from 4.49 % to 18.08 % as the RG content increased, while the digestion rate and digestion velocity constant were reduced by the incorporation of RG. Morphological observations showed that ERS was adhered and encapsulated by RG, and the specific area of starch granules were decreased after the addition of RG. The results of XRD and FTIR suggested that the long-range and short-range orders of ERS were improved due to the complexation with RG. The thickness of crystalline of ERS was increased while its amorphous region thickness was reduced by the supplementation with RG. The 1H NMR and 13C NMR data revealed that the branching degree and double helix content of ERS was increased by 46.24 % and 52.67 % when RG content reached to 12 %. Additionally, the addition of RG altered the molecular weight and chain length distribution of ERS. The α-amylase activity and glucoamylase activity was inhibited by RG. These results could provide a valuable basis for the application of RG in extruded rice starchy foods with lower glycemic index.


Asunto(s)
Oryza , Almidón , Almidón/química , Oryza/química , Glútenes/metabolismo , Digestión , Índice Glucémico
18.
New Phytol ; 241(1): 82-101, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37872738

RESUMEN

C4 plants typically operate a CO2 concentration mechanism from mesophyll (M) cells into bundle sheath (BS) cells. NADH dehydrogenase-like (NDH) complex is enriched in the BS cells of many NADP-malic enzyme (ME) type C4 plants and is more abundant in C4 than in C3 plants, but to what extent it is involved in the CO2 concentration mechanism remains to be experimentally investigated. We created maize and rice mutants deficient in NDH function and then used a combination of transcriptomic, proteomic, and metabolomic approaches for comparative analysis. Considerable decreases in growth, photosynthetic activities, and levels of key photosynthetic proteins were observed in maize but not rice mutants. However, transcript abundance for many cyclic electron transport (CET) and Calvin-Benson cycle components, as well as BS-specific C4 enzymes, was increased in maize mutants. Metabolite analysis of the maize ndh mutants revealed an increased NADPH : NADP ratio, as well as malate, ribulose 1,5-bisphosphate (RuBP), fructose 1,6-bisphosphate (FBP), and photorespiration intermediates. We suggest that by optimizing NADPH and malate levels and adjusting NADP-ME activity, NDH functions to balance metabolic and redox states in the BS cells of maize (in addition to ATP supply), coordinating photosynthetic transcript abundance and protein content, thus directly regulating the carbon flow in the two-celled C4 system of maize.


Asunto(s)
Carbono , NADH Deshidrogenasa , Carbono/metabolismo , NADH Deshidrogenasa/metabolismo , Zea mays/genética , Zea mays/metabolismo , Malatos/metabolismo , NADP/metabolismo , Dióxido de Carbono/metabolismo , Proteómica , Fotosíntesis , Oxidación-Reducción , Malato Deshidrogenasa/genética , Malato Deshidrogenasa/metabolismo , Hojas de la Planta/metabolismo
19.
Semin Cell Dev Biol ; 155(Pt A): 3-9, 2024 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36858897

RESUMEN

Maintaining proper metabolite levels in a complex metabolic network is crucial for maintaining a high flux through the network. In this paper, we discuss major regulatory mechanisms over the Calvin Benson Cycle (CBC) with regard to their roles in conferring homeostasis of metabolite levels in CBC. These include: 1) Redox regulation of enzymes in the CBC on one hand ensures that metabolite levels stay above certain lower bounds under low light while on the other hand increases the flux through the CBC under high light. 2) Metabolite regulations, especially allosteric regulations of major regulatory enzymes, ensure the rapid up-regulation of fluxes to ensure sufficient amount of triose phosphate is available for end product synthesis and concurrently avoid phosphate limitation. 3) A balanced activities of enzymes in the CBC help maintain balanced flux through CBC; some innate product feedback mechanisms, in particular the ADP feedback regulation of GAPDH and F6P feedback regulation of FBPase, exist in CBC to achieve such a balanced enzyme activities and hence flux distribution in the CBC for greater photosynthetic efficiency. Transcriptional regulation and natural variations of enzymes controlling CBC metabolite homeostasis should be further explored to maximize the potential of engineering CBC for greater efficiency.


Asunto(s)
Fosfatos , Fotosíntesis , Fotosíntesis/fisiología
20.
Plant Direct ; 7(12): e549, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38054113

RESUMEN

The mesophyll cells of grass leaves, such as rice, are traditionally viewed as displaying a relatively uniform pattern, in contrast to the clear distinctions of palisade and spongy layers in typical eudicot leaves. This quantitative analysis of mesophyll cell size and shape in rice leaves reveals that there is an inherent pattern in which cells in the middle layer of the mesophyll are larger and less circular and have a distinct orientation of their long axis compared to mesophyll cells in other layers. Moreover, this pattern was observed in a range of rice cultivars and species. The significance of this pattern with relation to potential photosynthetic function and the implication of the widespread use of middle layer mesophyll cells as typical of the rice leaf have been investigated and discussed.

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