Chloroplasts In Cells Research Articles

Fluorescent Staining and Quantification of Starch Granules in Chloroplasts of Live Plant Cells Using Fluorescein.

Plants use CO2, water, and light energy to generate carbohydrates through photosynthesis. During daytime, these carbohydrates are polymerized, leading to the accumulation of starch granules in chloroplasts. The catabolites produced by the degradation of these chloroplast starch granules are used for physiological responses and plant growth. Various staining methods, such as iodine staining, have previously been used to visualize the accumulation of chloroplast starch granules; however, these staining methods cannot be used to image live cells and/or provide confocal images with non-specific signals. In this study, we developed a new imaging method for the fluorescent observation of chloroplast starch granules in living plant cells by staining with fluorescein, a widely available fluorescent dye. This simple staining method, which involves soaking a leaf disk in staining solution, shows high specificity in confocal images. Fluorescent images of the stained tissue allow the cellular starch content of living cells to be quantified with the same level of accuracy as a conventional biochemical method (amyloglucosidase/α-amylase method). Fluorescein staining thus not only enables the easy and clear observation of chloroplast starch granules but also allows for precise quantification in living cells. Key features • Visualizes chloroplast starch granules stained with fluorescein in living cells. • Requires only simple specimen preparation with no reagents needed other than the staining solution. • Fluorescein is readily available worldwide. • Highly specific method for identifying chloroplast starch granules in confocal images. • Enables estimation of cellular starch content using fluorescent images.

Novel resources to investigate leaf plasmodesmata formation in C3 and C4 monocots.

Plasmodesmata (PD) are nanochannels that facilitate cell-to-cell transport in plants. More productive and photosynthetically efficient C4 plants form more PD at the mesophyll (M)-bundle sheath (BS) interface in their leaves than their less efficient C3 relatives. In C4 leaves, PD play an essential role in facilitating the rapid metabolite exchange between the M and BS cells to operate a biochemical CO2 concentrating mechanism, which increases the CO2 partial pressure at the site of Rubisco in the BS cells and hence photosynthetic efficiency. The genetic mechanism controlling PD formation in C3 and C4 leaves is largely unknown, especially in monocot crops, due to the technical challenge of quantifying these nanostructures with electron microscopy. To address this issue, we have generated stably transformed lines of Oryza sativa (rice, C3) and Setaria viridis (setaria, C4) with fluorescent protein-tagged PD to build the first spatiotemporal atlas of leaf pit field (cluster of PD) density in monocots without the need for electron microscopy. Across leaf development, setaria had consistently more PD connections at the M-BS wall interface than rice while the difference in M-M pit field density varied. While light was a critical trigger of PD formation, cell type and function determined leaf pit field density. Complementary temporal mRNA sequencing and gene co-expression network analysis revealed that the pattern of pit field density correlated with differentially expressed PD-associated genes and photosynthesis-related genes. PD-associated genes identified from our co-expression network analysis are related to cell wall expansion, translation and chloroplast signalling.

Genome-wide identification and expression analysis of SpUGE gene family and heterologous expression-mediated Arabidopsis thaliana tolerance to Cd stress

The UDP-glucose 4-epimerase (UGE) enzyme plays a critical role in plant growth and responses to abiotic stressors, such as heavy metal exposure. However, UGE-mediated remodeling of cell wall polysaccharides in response to these stressors remains poorly understood in willow. This study investigated the structure, function, and expression patterns of the UGE gene family in willow, focusing on cadmium treatment to elucidate how SpUGE1 enhances Cd resistance. Six SpUGE genes were identified through whole-genome sequencing and bioinformatics analysis, and they were mapped across five chromosomes. Quantitative PCR analysis revealed that, with the exception of SpUGE3, all genes showed their highest relative expression in the leaves. Under Cd treatment, members of the SpUGE gene family displayed varying levels of responsiveness, with SpUGE1 showing a marked increase in expression over time. In transgenic Arabidopsis thaliana overexpressing SpUGE1, the cellulose, hemicellulose, lignin, and pectin content significantly increased, with cellulose levels rising by >50 % and pectin by approximately 30 %. This overexpression conferred enhanced Cd resistance by increasing cell wall thickness through elevated cell wall polysaccharides, which reduced Cd uptake. Consequently, Cd content in the cell wall, chloroplasts, and mitochondria was significantly lower than that in wild-type plants, reducing cellular damage and improving Cd resistance. Overall, this study provides valuable theoretical and experimental insights into the role of the SpUGE1 gene family in willow.

Eggplant latent viroid is located in the chloroplasts and nuclei of eggplant infected cells

Viroids that belong to genera Avsunviroid and Pelamovirod (family Avsunviroidae) replicate and accumulate in the chloroplasts of infected cells. In this report, we confirmed by RNA in situ hybridization using digoxigenin-UTP-labelled riboprobes that the positive strands of eggplant latent viroid (ELVd), the only member of genus Elaviroid within the family Avsunviroidae, also accumulate in the chloroplasts of infected cells. However, comparison of ELVd in situ hybridization signals with those from bona fide chloroplastic and nuclear non-coding RNAs, such as chloroplast 5S rRNA and U1 small nuclear RNA, supports the notion that this viroid is also present in the nuclei of infected cells. These results suggest that the subcellular localization of viroids within the family Avsunviroidae may be more complex than previously assumed with dynamic presence in several compartments during the infectious cycle.

First report of toxigenic Amphidoma languida (Amphidomataceae, Dinophyceae) from the Pacific, with reference to intracellular ultrastructure and azaspiracid compounds

SUMMARYMorphology, phylogeny and azaspiracid (AZA) production of a strain of Amphidoma languida isolated from the subtropical Mexican Pacific were examined. Scanning electron microscopy showed the thecal plate arrangement of Am. languida from Mexico as Po, cp, X, 6′, 6′′, 6C, 5S, 6′′′, 2′′′′, with the prominent apical pore complex, the ventral pore on the anterior of the 1′ plate near the suture to the 6′ plate, and the antapical pore on the 2′′′′ plate, which are congruent with those of Am. languida reported from the Atlantic. The ventral depression was occasionally observed on the anterior end of Sa plate. Cells had a dinokaryotic nucleus positioned in the posterior part of the cell and parietal yellowish chloroplasts with a spherical pyrenoid in the episome. Transmission electron microscopy showed crystalline vesicles and tubular cytoplasmic invaginations in the pyrenoid, which resembled those reported from the most related non‐toxigenic species Amphidoma fulgens. The intracellular components, different from Am. fulgens, were oil droplets and lipid‐associated membranous structures. AZA‐2 was detected from the strain by liquid chromatography‐tandem mass spectrometry with a cell quota of 30.9 fg cell−1. Three other AZA‐related compounds were also detected. This is the first report of AZA‐producing Am. languida in the Pacific Ocean.

Lead-induced changes in plant cell ultrastructure: an overview.

Lead (Pb) is one of the most harmful toxic metals and causes severe damage to plants even at low concentrations. Pb inhibits plant development, reduces photosynthesis rates, and causes metabolic disfunctions. Plant cells display these alterations in the form of abnormal morphological modifications resulting from ultrastructural changes in the cell wall, plasma membrane, chloroplast, endoplasmic reticulum, mitochondria, and nuclei. Depending on plant tolerance capacity, the ultrastructural changes could be either a sign of toxicity that limits plant development or an adaptive strategy to cope with Pb stress. This paper gathers data on Pb-induced changes in cell ultrastructure observed in many tolerant and hyperaccumulator plants and describes the ultrastructural changes that appear to be mechanisms to alleviate Pb toxicity. The different modifications caused by Pb in cell organelles are summarized and reinforced with hypotheses that provide an overview of plant responses to Pb stress and explain the physiological and morphological changes that occur in tolerant plants. These ultrastructural modifications could help assess the potential of plants for use in phytoremediation.

In vivo biosensing of subcellular pyruvate pools reveals photosynthesis-dependent metabolite dynamics in Nicotiana benthamiana

Abstract Pyruvate is central to metabolism across biology. It acts as a metabolic hub linking major pathways including glycolysis, the Krebs cycle, fermentation, and synthesis of amino acids, fatty acids, isoprenoids, and nucleotides. Even though the central role of pyruvate is well established biochemically, there is a remarkable gap in our understanding of how pyruvate levels behave within cells, where pyruvate is distributed across different compartments. Moreover, differential changes in pyruvate pools may occur rapidly upon changes in metabolic fluxes. Recently, this problem has been addressed by the development of a genetically encoded pyruvate biosensor to provide first insights into the pyruvate dynamics in animal cells. Here, we established in vivo biosensing of pyruvate in plants. We provided advanced characterization of the biosensor properties and demonstrated the functionality of the sensor in the cytosol, the mitochondria, and the chloroplasts of Nicotiana benthamiana epidermal cells. Finally, we harnessed the tool to investigate the impact of photosynthesis on pyruvate with unprecedented spatial and temporal resolution, revealing pronounced changes in subcellular pyruvate pools. While highlighting the current limitations of the biosensor, this study provides proof-of-concept for how the dynamics and regulation of central carbon metabolites can be revealed in living plant tissues.

FgCWM1 modulates TaNDUFA9 to inhibit SA synthesis and reduce FHB resistance in wheat

BackgroundFusarium head blight (FHB) significantly impacts wheat yield and quality. Understanding the intricate interaction mechanisms between Fusarium graminearum (the main pathogen of FHB) and wheat is crucial for developing effective strategies to manage and this disease. Our previous studies had shown that the absence of the cell wall mannoprotein FgCWM1, located at the outermost layer of the cell wall, led to a decrease in the pathogenicity of F. graminearum and induced the accumulation of salicylic acid (SA) in wheat. Hence, we propose that FgCWM1 may play a role in interacting between F. graminearum and wheat, as its physical location facilitates interaction effects.ResultsIn this study, we have identified that the C-terminal region of NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 9 (NDUFA9) could interact with FgCWM1 through the yeast two-hybrid assay. The interaction was further confirmed through the combination of Co-IP and BiFC analyses. Consistently, the results of subcellular localization indicated that TaNDUFA9 was localized in the cytoplasm adjacent to the cell membrane and chloroplasts. The protein was also detected to be associated with mitochondria and positively regulated complex I activity. The loss-of-function mutant of TaNDUFA9 exhibited a delay in flowering, decreased seed setting rate, and reduced pollen fertility. However, it exhibited elevated levels of SA and increased resistance to FHB caused by F. graminearum infection. Meanwhile, inoculation with the FgCWM1 deletion mutant strain led to increased synthesis of SA in wheat.ConclusionsThese findings suggest that TaNDUFA9 inhibits SA synthesis and FHB resistance in wheat. FgCWM1 enhances this inhibition by interacting with the C-terminal region of TaNDUFA9, ultimately facilitating F. graminearum infection in wheat. This study provides new insights into the interaction mechanism between F. graminearum and wheat. TaNDUFA9 could serve as a target gene for enhancing wheat resistance to FHB.

Accumulation of dually targeted StGPT1 in chloroplasts mediated by StRFP1, an E3 ubiquitin ligase, enhances plant immunity.

Chloroplasts play a crucial role in essential processes, such as photosynthesis and the synthesis of primary and diverse secondary metabolites. Recent studies have also highlighted their significance linked to phytohormone production in plant immunity, especially SA and JA. Ubiquitination, a key posttranslational modification, usually leads to target protein degradation, which acts as a signal for remodeling the proteome via the induction of protein endocytosis or targeting to other membrane associated systems. Previously, the potato E3 ligase StRFP1 was shown to enhance resistance against Phytophthora infestans, but its mechanism remained unclear. Here, we demonstrate that StRFP1 interacted with the dually localized plastid glucose 6-phosphate transporter StGPT1 on the endoplasmic reticulum (ER). Transiently expressed StGPT1-GFP located on the chloroplast and ER in plant cells. Overexpression of StGPT1 enhances late blight resistance in potato and Nicotiana benthamiana, activates immune responses, including ROS bursts and up-regulation of PTI marker genes. The resistance function of StGPT1 seems to be related to its dual localization. Remarkably, StRFP1 ubiquitinates StGPT1 at the ER, possibly due to its merely transient function in peroxisomes, leading to apparent accumulation in chloroplasts. Our findings point to a novel mechanism by which a plant E3 ligase contributes to immunity via interacting with dually targeted GPT1 at the ER of plant cells.

Nonlinear models based on leaf architecture traits explain the variability of mesophyll conductance across plant species.

Mesophyll conductance ( ) describes the efficiency with which moves from substomatal cavities to chloroplasts. Despite the stipulated importance of leaf architecture in affecting , there remains a considerable ambiguity about how and whether leaf anatomy influences . Here, we employed nonlinear machine-learning models to assess the relationship between 10 leaf architecture traits and . These models used leaf architecture traits as predictors and achieved excellent predictability of . Dissection of the importance of leaf architecture traits in the models indicated that cell wall thickness and chloroplast area exposed to internal airspace have a large impact on interspecific variation in . Additionally, other leaf architecture traits, such asleaf thickness, leaf densityand chloroplast thickness, emerged as important predictors of . We also found significant differences in the predictability between models trained on different plant functional types. Therefore, by moving beyond simple linear and exponential models, our analyses demonstrated that a larger suite of leaf architecture traits drive differences in than has been previously acknowledged. These findings pave the way for modulating by strategies that modify its leaf architecture determinants.

Alternaria solani effectors AsCEP19 and AsCEP20 reveal novel functions in pathogenicity and conidiogenesis.

Alternaria solani is an important necrotrophic pathogen causing potato early blight. Previous studies have provide preliminary evidence that specific effectors AsCEP19 and AsCEP20 contribute to virulence, but their respective functions, localization, and pathogenic mechanisms during the infection process of A. solani remain unclear. Here, we have systematically studied the specific effectors AsCEP19 and AsCEP20 for the first time, which are essential for conidial maturation. The deletion of AsCEP19 and AsCEP20 can significantly impair fungal pathogenicity. Additionally, we preliminarily revealed that AsCEP19 and AsCEP20 target the chloroplasts of host cells. Our findings further enhance our understanding of the molecular mechanisms underlying the virulence of necrotrophic pathogens.

Single-cell RNA-sequencing provides new insights into the cell-specific expression patterns and transcriptional regulation of photosynthetic genes in bermudagrass leaf blades

As an important warm-season turfgrass species, bermudagrass (Cynodon dactylon L.) flourishes in warm areas around the world due to the existence of the C4 photosynthetic pathway. However, how C4 photosynthesis operates in bermudagrass leaves is still poorly understood. In this study, we performed single-cell RNA-sequencing on 5296 cells from bermudagrass leaf blades. Eight cell clusters corresponding to mesophyll, bundle sheath, epidermis and vascular bundle cells were successfully identified using known cell marker genes. Expression profiling indicated that genes encoding NADP-dependent malic enzymes (NADP-MEs) were highly expressed in bundle sheath cells, whereas NAD-ME genes were weakly expressed in all cell types, suggesting C4 photosynthesis of bermudagrass leaf blades might be NADP-ME type rather than NAD-ME type. The results also indicated that starch synthesis-related genes showed preferential expression in bundle sheath cells, whereas starch degradation-related genes were highly expressed in mesophyll cells, which agrees with the observed accumulation of starch-filled chloroplasts in bundle sheath cells. Gene co-expression analysis further revealed that different families of transcription factors were co-expressed with multiple C4 photosynthesis-related genes, suggesting a complex transcription regulatory network of C4 photosynthesis might exist in bermudagrass leaf blades. These findings collectively provided new insights into the cell-specific expression patterns and transcriptional regulation of photosynthetic genes in bermudagrass.

Genome-wide analysis of filamentous temperature-sensitive H protease (ftsH) gene family in soybean.

The filamentous temperature-sensitive H protease (ftsH) gene family belongs to the ATP-dependent zinc metalloproteins, and ftsH genes play critical roles in plant chloroplast development and photosynthesis. In this study, we performed genome-wide identification and a systematic analysis of soybean ftsH genes. A total of 18 GmftsH genes were identified. The subcellular localization was predicted to be mainly in cell membranes and chloroplasts, and the gene structures, conserved motifs, evolutionary relationships, and expression patterns were comprehensively analyzed. Phylogenetic analysis of the ftsH gene family from soybean and various other species revealed six distinct clades, all of which showed a close relationship to Arabidopsis thaliana. The members of the GmftsH gene family were distributed on 13 soybean chromosomes, with intron numbers ranging from 3 to 15, 13 pairs of repetitive segment. The covariance between these genes and related genes in different species of Oryza sativa, Zea mays, and Arabidopsis thaliana was further investigated. The transcript expression data revealed that the genes of this family showed different expression patterns in three parts, the root, stem, and leaf, and most of the genes were highly expressed in the leaves of the soybean plants. Fluorescence-based real-time quantitative PCR (qRT-PCR) showed that the expression level of GmftsH genes varied under different stress treatments. Specifically, the genes within this family exhibited various induction levels in response to stress conditions of 4℃, 20% PEG-6000, and 100 mmol/L NaCl. These findings suggest that the GmftsH gene family may play a crucial role in the abiotic stress response in soybeans. It was also found that the GmftsH7 gene was localized on the cell membrane, and its expression was significantly upregulated under 4 ℃ treatment. In summary, by conducting a genome-wide analysis of the GmftsH gene family, a strong theoretical basis is established for future studies on the functionality of GmftsH genes. This research can potentially serve as a guide for enhancing the stress tolerance characteristics of soybean.

An iron-deficiency tolerant genotype of sorghum effectively localizes iron to the thylakoid membranes of the bundle sheath cells

ABSTRACT Although sorghum (Sorghum bicolor L.), a C4 grass plant, requires a higher iron (Fe) concentration in its leaves for sufficient growth compared to C3 grass plants, there are differences in Fe-deficiency tolerance among sorghum genotypes. C4 plant sorghum localizes Fe in bundle sheath (BS) cells as a major site for CO2 assimilation; however, the response of chloroplasts in BS cells to Fe deficiency remains unknown. We compared the allocation of Fe and proteins involved in the photosystems between Fe-deficiency-tolerant and Fe-deficiency-susceptible sorghum genotypes. The distribution patterns of the Fe-requiring core proteins of photosystems I and II were the same in both genotypes, whereas the tolerant genotype, line D100, allocated more Fe to the BS thylakoid membranes than the susceptible genotype, regardless of Fe nutritional status and leaf Fe content. These results suggest that the tolerant D100 sorghum line has mechanisms to supply sufficient Fe to the BS thylakoid membranes.

Cutinsomes of Malus Mill. (Rosaceae) leaf and pericarp: genesis, localization, and transport

New data were obtained on specific bionanostructures, cutinsomes, which are involved in the formation of cuticles on the surface of leaf blades and pericarp of Malus domestica Borkh (Malus Mill., Rosaceae)introduced to the mountains at the altitudes of 1200 and 1700 m above sea level. Cutinsomes, which are electron-dense structures of spherical shape, have been identified by transmission electron microscopy. It was demonstrated that plastids can be involved in the synthesis of their constituent nanocomponents. The greatest number of nanoparticles was observed in the granal thylakoid lumen of the chloroplasts in palisade mesophyll cells and pericarp hypodermal cells. The transmembrane transport of cutinsomes into the cell wall cuticle proper by exocytosis has been visualized for the first time. The plasma membrane is directly involved in the excretion of nanostructures from the cell. Nanoparticles of cutinsomes in the form of necklace-like formations line up in a chain near cell walls, merge into larger conglomerates and are loaded into plasmalemma invaginations, and then, in membrane packing, they move into the cuticle, which covers both outer and inner cell walls of external tissues. The original materials obtained by us supplement the ideas about the non-enzymatic synthesis of cuticle components available in the literature and expand the cell compartment geography involved in this process.

Zn Check: Revolutionizing Plant Nutrition with Amino Acid-based Zinc Chelation

Zinc plays a vital role in plant growth and development, impacting essential physiological processes such as cell division, nitrogen, carbohydrate metabolism and chloroplast development. However, zinc deficiency poses a significant challenge in agriculture, particularly in crops grown on calcareous soils. Traditional zinc fertilizers, like Zn EDTA, face limitations in alkaline soils, prompting the need for innovative solutions. This study introduces an amino acid-based chelating agent, Zinc Check, synthesized to address these challenges effectively. The research demonstrates the stability and efficacy of Zinc Check across diverse soil conditions, ensuring zinc availability to plants. Through various analytical techniques and pot trials with Pak choi plants, the study confirms the effectiveness of Zinc Check in promoting plant growth and chlorophyll synthesis, surpassing the performance of conventional zinc fertilizers. Moreover, the investigation explores the pH tolerance of Zinc Check, highlighting its stability across a wide pH range. Overall, this study underscores the importance of innovative solutions like Zinc Check in addressing zinc deficiency and enhancing agricultural productivity, contributing to global food security efforts.

Partial root-zone drying irrigation improves intrinsic water-use efficiency and maintains high photosynthesis by uncoupling stomatal and mesophyll conductance in cotton leaves.

Partial root-zone drying irrigation (PRD) can improve water-use efficiency (WUE) without reductions in photosynthesis; however, the mechanism by which this is attained is unclear. To amend that, PRD conditions were simulated by polyethylene glycol 6000 in a root-splitting system and the effects of PRD on cotton growth were studied. Results showed that PRD decreased stomatal conductance (gs) but increased mesophyll conductance (gm). Due to the contrasting effects on gs and gm, net photosynthetic rate (AN) remained unaffected, while the enhanced gm/gs ratio facilitated a larger intrinsic WUE. Further analyses indicated that PRD-induced reduction of gs was related to decreased stomatal size and stomatal pore area in adaxial and abaxial surface which was ascribed to lower pore length and width. PRD-induced variation of gm was ascribed to the reduced liquid-phase resistance, due to increases in chloroplast area facing to intercellular airspaces and the ratio of chloroplast surface area to total mesophyll cell area exposed to intercellular airspaces, as well as to decreases in the distance between cell wall and chloroplast, and between adjacent chloroplasts. The above results demonstrate that PRD, through alterations to stomatal and mesophyll structures, decoupled gs and gm responses, which ultimately increased intrinsic WUE and maintained AN.

Mutation mapping of a variegated EMS tomato reveals an FtsH-like protein precursor potentially causing patches of four phenotype classes in the leaves with distinctive internal morphology

BackgroundLeaf variegation is an intriguing phenomenon observed in many plant species. However, questions remain on its mechanisms causing patterns of different colours. In this study, we describe a tomato plant detected in an M2 population of EMS mutagenised seeds, showing variegated leaves with sectors of dark green (DG), medium green (MG), light green (LG) hues, and white (WH). Cells and tissues of these classes, along with wild-type tomato plants, were studied by light, fluorescence, and transmission electron microscopy. We also measured chlorophyll a/b and carotene and quantified the variegation patterns with a machine-learning image analysis tool. We compared the genomes of pooled plants with wild-type-like and mutant phenotypes in a segregating F2 population to reveal candidate genes responsible for the variegation.ResultsA genetic test demonstrated a recessive nuclear mutation caused the variegated phenotype. Cross-sections displayed distinct anatomy of four-leaf phenotypes, suggesting a stepwise mesophyll degradation. DG sectors showed large spongy layers, MG presented intercellular spaces in palisade layers, and LG displayed deformed palisade cells. Electron photomicrographs of those mesophyll cells demonstrated a gradual breakdown of the chloroplasts. Chlorophyll a/b and carotene were proportionally reduced in the sectors with reduced green pigments, whereas white sectors have hardly any of these pigments. The colour segmentation system based on machine-learning image analysis was able to convert leaf variegation patterns into binary images for quantitative measurements. The bulk segregant analysis of pooled wild-type-like and variegated progeny enabled the identification of SNP and InDels via bioinformatic analysis. The mutation mapping bioinformatic pipeline revealed a region with three candidate genes in chromosome 4, of which the FtsH-like protein precursor (LOC100037730) carries an SNP that we consider the causal variegated phenotype mutation. Phylogenetic analysis shows the candidate is evolutionary closest to the Arabidopsis VAR1. The synonymous mutation created by the SNP generated a miRNA binding site, potentially disrupting the photoprotection mechanism and thylakoid development, resulting in leaf variegation.ConclusionWe described the histology, anatomy, physiology, and image analysis of four classes of cell layers and chloroplast degradation in a tomato plant with a variegated phenotype. The genomics and bioinformatics pipeline revealed a VAR1-related FtsH mutant, the first of its kind in tomato variegation phenotypes. The miRNA binding site of the mutated SNP opens the way to future studies on its epigenetic mechanism underlying the variegation.

Rice bundle sheath cell shape is regulated by the timing of light exposure during leaf development.

Plant leaves contain multiple cell types which achieve distinct characteristics whilst still coordinating development within the leaf. The bundle sheath possesses larger individual cells and lower chloroplast content than the adjacent mesophyll, but how this morphology is achieved remains unknown. To identify regulatory mechanisms determining bundle sheath cell morphology we tested the effects of perturbing environmental (light) and endogenous signals (hormones) during leaf development of Oryza sativa (rice). Total chloroplast area in bundle sheath cells was found to increase with cell size as in the mesophyll but did not maintain a 'set-point' relationship, with the longest bundle sheath cells demonstrating the lowest chloroplast content. Application of exogenous cytokinin and gibberellin significantly altered the relationship between cell size and chloroplast biosynthesis in the bundle sheath, increasing chloroplast content of the longest cells. Delayed exposure to light reduced the mean length of bundle sheath cells but increased corresponding leaf length, whereas premature light reduced final leaf length but did not affect bundle sheath cells. This suggests that the plant hormones cytokinin and gibberellin are regulators of the bundle sheath cell-chloroplast relationship and that final bundle sheath length may potentially be affected by light-mediated control of exit from the cell cycle.

Biological Insights into Energy Storage Technologies

In the face of increasing energy demands and environmental concerns, the search for sustainable and efficient energy storage technologies has intensified. This review presents a holistic survey of innovative solutions by examining biological approaches. The study proceeds through three thematic sections: Biological Fuel Cells and Battery Systems, Photosynthesis and Solar Energy Storage, and Energy Generation at the Cellular Level. The first section, Biological Fuel Cells and Battery Systems describes the integration of biological processes into energy storage mechanisms. The use of biological systems and their contribution to the development of environmentally friendly and high performance energy storage technologies are discussed. In the 2nd section, Photosynthesis and Solar Energy Storage are very prominent in sustainability and energy efficiency issues in terms of both energy production and energy source food production while reducing carbon dioxide with photosynthesis-based energy storage methods. Energy production at the cellular level is discussed in the last section, Adenosine triphosphate (ATP), which is necessary for the cell to perform processes such as growth, reproduction and response to environmental stimuli, is characterized as the primary fuel. ATP production is carried out by mitochondria in animal cells and chloroplast in plant cells. Energy storage at the cellular level is carried out by molecules such as glycogen and lipids in animal cells and starch in plant cells. Considering all three issues, it has been observed that biological-based energy storage methods have numerous advantages in terms of sustainability and energy efficiency. In application areas where engineering approaches are at the forefront, it is thought that it may be possible to design more sustainable and highly energy efficient energy production systems by gaining new perspectives with biology-based simulation studies.