RNA editing factor SlORRM2 regulates the formation of fruit pointed tips in tomato.

Domestication of tomato (Solanum lycopersicum) has led to large variation in fruit size and morphology. The development of the distal end of the fruit is a critical factor in determining its overall shape. However, the intricate mechanisms underlying distal fruit development require further exploration. This study aimed to investigate the regulatory role of an organelle RNA recognition motif (RRM)-containing protein SlORRM2 in tomato fruit morphology development. Mutant plants lacking SlORRM2 exhibited fruits with pointed tips at the distal end. However, this phenotype could be successfully restored through the implementation of a "functional complementation" strategy. Our findings suggest that the formation of pointed tips in the fruits of the CR-slorrm2 mutants is linked to alterations in the development of the ovary and style. We observed a substantial decrease in the levels of indole-3-acetic acid (IAA) and altered expression of IAA-related response genes in the ovary and style tissues of CR-slorrm2. Moreover, our data demonstrated that SlORRM2 plays a role in regulating mitochondrial RNA editing sites, particularly within genes encoding various respiratory chain subunits. Additionally, the CR-slorrm2 mutants exhibited modified organellar morphology and increased levels of reactive oxygen species (ROS). These findings provide valuable insights into the mechanisms underlying the formation of fruit pointed tips in tomato and offer genetic resources for tomato breeding.

[Investigating the impact of silencing an RNA-binding protein gene SlRBP1 on tomato photosynthesis through RNA-sequencing analysis].

Photosynthesis in plants directly affects the synthesis and accumulation of organic matter, which directly influences crop yield. RNA-binding proteins (RBPs) are involved in the regulation of a variety of physiological functions in plants, while the functions of RBPs in photosynthesis have not been clearly elucidated. To investigate the effect of a glycine-rich RNA-binding protein (SlRBP1) in tomato on plant photosynthesis, a stably inherited SlRBP1 silenced plant in Alisa Craig was obtained by plant tissue culture using artificial small RNA interference. It turns out that the size of the tomato fruit was reduced and leaves significantly turned yellow. Chlorophyll(Chl) content measurement, Chl fluorescence imaging and chloroplast transmission electron microscopy revealed that the chloroplast morphology and structure of the leaves of tomato amiR-SlRBP1 silenced plants were disrupted, and the chlorophyll content was significantly reduced. Measurement of photosynthesis rate of wild-type and amiR-SlRBP1 silenced plants in the same period demonstrated that the photosynthetic rate of these plants was significantly reduced, and analysis of RNA-seq data indicated that silencing of SlRBP1 significantly reduced the expression of photosynthesis-related genes, such as PsaE, PsaL, and PsbY, and affected the yield of tomato fruits through photosynthesis.

Exploring the endangerment mechanisms of Hipposideros pomona based on molecular phylogeographic methods.

The endangerment mechanisms of various species are a focus of studies on biodiversity and conservation biology. Hipposideros pomona is an endangered species, but the reasons behind its endangerment remain unclear. We investigated the endangerment mechanisms of H. pomona using mitochondrial DNA, nuclear DNA, and microsatellite loci markers. The results showed that the nucleotide diversity of mitochondria DNA and heterozygosity of microsatellite markers were high (π = 0.04615, H O = 0.7115), whereas the nucleotide diversity of the nuclear genes was low (THY: π = 0.00508, SORBS2: π = 0.00677, ACOX2: π = 0.00462, COPS7A: π = 0.00679). The phylogenetic tree and median-joining network based on mitochondrial DNA sequences clustered the species into three clades, namely North Vietnam-Fujian, Myanmar-West Yunnan, and Laos-Hainan clades. However, joint analysis of nuclear genes did not exhibit clustering. Analysis of molecular variance revealed a strong population genetic structure; IMa2 analysis did not reveal significant gene flow between all groups (p > .05), and isolation-by-distance analysis revealed a significant positive correlation between genetic and geographic distances (p < .05). The mismatch distribution analysis, neutral test, and Bayesian skyline plots revealed that the H. pomona population were relatively stable and exhibited a contraction trend. The results implied that H. pomona exhibits female philopatry and male-biased dispersal. The Hengduan Mountains could have acted as a geographical barrier for gene flow between the North Vietnam-Fujian clade and the Myanmar-West Yunnan clade, whereas the Qiongzhou Strait may have limited interaction between the Hainan populations and other clades. The warm climate during the second interglacial Quaternary period (c. 0.33 Mya) could have been responsible for species differentiation, whereas the cold climate during the late Quaternary last glacial maximum (c. 10 ka BP) might have caused the overall contraction of species. The lack of significant gene flow in nuclear microsatellite loci markers among the different populations investigated reflects recent habitat fragmentation due to anthropogenic activities; thus, on-site conservation of the species and restoration of gene flow corridors among populations need immediate implementation.

The Glycine-Rich RNA-Binding Protein Is a Vital Post-Transcriptional Regulator in Crops.

Glycine-rich RNA binding proteins (GR-RBPs), a branch of RNA binding proteins (RBPs), play integral roles in regulating various aspects of RNA metabolism regulation, such as RNA processing, transport, localization, translation, and stability, and ultimately regulate gene expression and cell fate. However, our current understanding of GR-RBPs has predominantly been centered on Arabidopsis thaliana, a model plant for investigating plant growth and development. Nonetheless, an increasing body of literature has emerged in recent years, shedding light on the presence and functions of GRPs in diverse crop species. In this review, we not only delineate the distinctive structural domains of plant GR-RBPs but also elucidate several contemporary mechanisms of GR-RBPs in the post-transcriptional regulation of RNA. These mechanisms encompass intricate processes, including RNA alternative splicing, polyadenylation, miRNA biogenesis, phase separation, and RNA translation. Furthermore, we offer an exhaustive synthesis of the diverse roles that GR-RBPs fulfill within crop plants. Our overarching objective is to provide researchers and practitioners in the field of agricultural genetics with valuable insights that may inform and guide the application of plant genetic engineering for enhanced crop development and sustainable agriculture.

Dicer-like2b suppresses the wiry leaf phenotype in tomato induced by tobacco mosaic virus.

Dicer-like (DCL) proteins are principal components of RNA silencing, a major defense mechanism against plant virus infections. However, their functions in suppressing virus-induced disease phenotypes remain largely unknown. Here, we identified a role for tomato (Solanum lycopersicum) DCL2b in regulating the wiry leaf phenotype during defense against tobacco mosaic virus (TMV). Knocking out SlyDCL2b promoted TMV accumulation in the leaf primordium, resulting in a wiry phenotype in distal leaves. Biochemical and bioinformatics analyses showed that 22-nt virus-derived small interfering RNAs (vsiRNAs) accumulated less abundantly in slydcl2b mutants than in wild-type plants, suggesting that SlyDCL2b-dependent 22-nt vsiRNAs are required to exclude virus from leaf primordia. Moreover, the wiry leaf phenotype was accompanied by upregulation of Auxin Response Factors (ARFs), resulting from a reduction in trans-acting siRNAs targeting ARFs (tasiARFs) in TMV-infected slydcl2b mutants. Loss of tasiARF production in the slydcl2b mutant was in turn caused by inhibition of miRNA390b function. Importantly, silencing SlyARF3 and SlyARF4 largely restored the wiry phenotype in TMV-infected slydcl2b mutants. Our work exemplifies the complex relationship between RNA viruses and the endogenous RNA silencing machinery, whereby SlyDCL2b protects the normal development of newly emerging organs by excluding virus from these regions and thus maintaining developmental silencing.

Synthesis, characterization and crystallization kinetics of a bio-based, heat-resistance nylon 5T/10T.

The rapid consumption of fossil resources and its adverse impact on the environment require the use of bio-based materials to replace petrochemical products. In this study, we present a bio-based, heat-resistant engineering plastic, poly(pentamethylene terephthalamide) (nylon 5T). To address the issues of the narrow processing window and difficulty in melting processing of nylon 5T, we introduced more flexible decamethylene terephthalamide (10T) units to create a copolymer, nylon 5T/10T. The chemical structure was confirmed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (13C-NMR). We investigated the influence of 10T units on the thermal performance, crystallization kinetics, crystallization activation energy, and crystal structures of the copolymers. Our results demonstrate that the crystal growth mode of nylon 5T is a two-dimensional discoid growth pattern, while nylon 5T/10T exhibits a two-dimensional discoid or three-dimensional spherical growth pattern. The melting temperature, crystallization temperature, and crystallization rate first decrease and then increase, and crystal activation energy first increases and then decreases as a function of 10T units. These effects are attributed to the combined impact of molecular chain structure and polymer crystalline region. Bio-based nylon 5T/10T shows excellent heat resistance (melting temperature > 280 °C) and a wider processing window than nylon 5T and 10T, which is a promising heat-resistant engineering plastic.

Experimental and Numerical Calculation Study on the Slope Stability of the Yellow River Floodplain from Wantan Town to Liuyuankou.

More than two million people live on the floodplains along the middle and lower streams of the Yellow River. The rapid development of industry and agriculture on both sides of the Yellow River has caused serious pollution of the floodplain soil. Erosion by water has led to the destruction of the floodplain which has not only compressed people's living space but also resulted in a large amount of sediment containing heavy metals entering the river, aggravating water pollution. To further study the law governing the release of pollutants in soil, this work, based on field surveys of the Yellow River floodplain slopes from Wantan town to Liuyuankou, was focused on determining the failure mechanism and laws for the floodplain slope through the combination of a flume experiment and numerical calculations. The results showed that the floodplain slopes, composed of clay and silty sand, presented an interactive structure. Under the action of water erosion, the slope was first scoured to form a curved, suspended layer structure, and then the upper suspended layer toppled. The bank stability coefficient decreased by about 65% when the scour width increased from 0.07 m to 0.42 m, and the water content increased from 20% to 40%. For the failure characteristics, the angle of the failure surface was negatively correlated with the scour width, and the distance from the top failure surface to the bank edge was about 2.5 times that of the scour width.

SlRIP1b is a global organellar RNA editing factor, required for normal fruit development in tomato plants.

RNA editing in plant organelles involves numerous C-U conversions, which often restore evolutionarily conserved codons and may generate new translation initiation and termination codons. These RNA maturation events rely on a subset of nuclear-encoded protein cofactors. Here, we provide evidence of the role of SlRIP1b on RNA editing of mitochondrial transcripts in tomato (Solanum lycopersicum) plants. SlRIP1b is a RIP/MORF protein that was originally identified as an interacting partner of the organellar editing factor SlORRM4. Mutants of SlRIP1b, obtained by CRISPR/Cas9 strategy, exhibited abnormal carpel development and grew into fruit with more locules. RNA-sequencing revealed that SlRIP1b affects the C-U editing of numerous mitochondrial pre-RNA transcripts and in particular altered RNA editing of various cytochrome c maturation (CCM)-related genes. The slrip1b mutants display increased H2 O2 and aberrant mitochondrial morphologies, which are associated with defects in cytochrome c biosynthesis and assembly of respiratory complex III. Taken together, our results indicate that SlRIP1b is a global editing factor that plays a key role in CCM and oxidative phosphorylation system biogenesis during fruit development in tomato plants. These data provide important insights into the molecular roles of organellar RNA editing factors during fruit development.

A New Biotin Labeling and High-Molecular-Weight RNA Northern Method and Its Application in Viral RNA Detection.

Viruses cause severe crop losses. Studying the interaction between viruses and plants is very important for development of control measures. Northern blot is a well-accepted but very challenging technique to monitor the infection of viruses. Here, we modified the high-molecular-weight (hmw)RNA Northern blot experiment process, utilizing vertical electrophoresis to separate the RNA with denatured agarose gel. This protocol is compatible with regular equipment for Western blots and small RNA Northern blots and requires less input of total RNA. A new method to label the probe with biotin was also developed, which requires commonly used T4 DNA polymerase and detects viral RNA with high sensitivity. These new protocols made hmwRNA Northern blot cost-effective and easy-to-operate, very suitable for studying virus-host interactions.

Mongolian Medicine Areca Thirteen Pill (GY-13) Improved Depressive Syndrome via upregulating cAMP/PKA/CREB/BDNF signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Areca Thirteen Pill, also called Gao You-13 (GY-13), is a traditional Mongolian herbal formula and has been extensively used to treat depression in Mongolian areas, which belongs to Heyi disease in Mongolian medicine. Major depressive disorder is a serious psychiatric disease, only one-third of individuals with depression are responsive to current antidepressants in clinic. Growing attention has been attracted by traditional herbal medicines in fighting depression because they are considered safer alternatives to pharmacotherapy. AIM OF THE STUDY: To reveal the mechanism of GY-13 in the treatment of depression. MATERIALS AND METHODS: The rat depression model was established by chronic unpredictable mild stress (CUMS), and primary hippocampal neurons were used to construct a glutamate-induced excitotoxicity model. The antidepressant effect of GY-13 was then assessed by performing sucrose preference tests, open field tests, and body weight measurements on rats. The expression of cAMP and PKA, mRNA levels of brain-derived neurotrophic factor (BDNF) and cAMP response element binding protein (CREB), and hippocampal neuronal apoptosis were measured. RESULTS: The results indicate that GY-13 significantly improves depression-like behavior, rescues decreased cAMP， PKA, recovers the mRNA levels of CREB and BDNF, and increases the proliferative activity of hippocampus. In addition, blockade of PKA reverses the effects of GY-13 treatment on CREB mRNA, BDNF mRNA levels. In vitro, GY-13 treatment increased hippocampal proliferative activity and attenuated Glu-induced apoptosis of hippocampal neurons as well as reduced CREB mRNA and BDNF mRNA expression levels. CONCLUSIONS: Our research demonstrated that GY-13 treatment exerted a potent antidepressant action via activation of cAMP/CREB/BDNF signaling pathway, promoting proliferation, and suppressing apoptosis. This research provides molecular biological ground for developing GY-13 into a potent alternative for the intervention of depression.

SlRBP1 promotes translational efficiency via SleIF4A2 to maintain chloroplast function in tomato.

Many glycine-rich RNA-binding proteins (GR-RBPs) have critical functions in RNA processing and metabolism. Here, we describe a role for the tomato (Solanum lycopersicum) GR-RBP SlRBP1 in regulating mRNA translation. We found that SlRBP1 knockdown mutants (slrbp1) displayed reduced accumulation of total chlorophyll and impaired chloroplast ultrastructure. These phenotypes were accompanied by deregulation of the levels of numerous key transcripts associated with chloroplast functions in slrbp1. Furthermore, native RNA immunoprecipitation-sequencing (nRIP-seq) recovered 61 SlRBP1-associated RNAs, most of which are involved in photosynthesis. SlRBP1 binding to selected target RNAs was validated by nRIP-qPCR. Intriguingly, the accumulation of proteins encoded by SlRBP1-bound transcripts, but not the mRNAs themselves, was reduced in slrbp1 mutants. Polysome profiling followed by RT-qPCR assays indicated that the polysome occupancy of target RNAs was lower in slrbp1 plants than in wild-type. Furthermore, SlRBP1 interacted with the eukaryotic translation initiation factor SleIF4A2. Silencing of SlRBP1 significantly reduced SleIF4A2 binding to SlRBP1-target RNAs. Taking these observations together, we propose that SlRBP1 binds to and channels RNAs onto the SleIF4A2 translation initiation complex and promotes the translation of its target RNAs to regulate chloroplast functions.

Small RNAs Participate in Plant-Virus Interaction and Their Application in Plant Viral Defense.

Small RNAs are significant regulators of gene expression, which play multiple roles in plant development, growth, reproductive and stress response. It is generally believed that the regulation of plants' endogenous genes by small RNAs has evolved from a cellular defense mechanism for RNA viruses and transposons. Most small RNAs have well-established roles in the defense response, such as viral response. During viral infection, plant endogenous small RNAs can direct virus resistance by regulating the gene expression in the host defense pathway, while the small RNAs derived from viruses are the core of the conserved and effective RNAi resistance mechanism. As a counter strategy, viruses evolve suppressors of the RNAi pathway to disrupt host plant silencing against viruses. Currently, several studies have been published elucidating the mechanisms by which small RNAs regulate viral defense in different crops. This paper reviews the distinct pathways of small RNAs biogenesis and the molecular mechanisms of small RNAs mediating antiviral immunity in plants, as well as summarizes the coping strategies used by viruses to override this immune response. Finally, we discuss the current development state of the new applications in virus defense based on small RNA silencing.

Lack of TRPV1 aggravates obesity-associated hypertension through the disturbance of mitochondrial Ca2+ homeostasis in brown adipose tissue.

The combination of obesity and hypertension is associated with high morbidity and mortality; however, the mechanism underlying obesity-induced hypertension remains unclear. In this study, we detected the possible effects of TRPV1, a previously identified antihypertensive calcium (Ca2+) channel in adipose tissue, on the occurrence of obesity and hypertension in mice lacking UCP1, a spontaneously genetically manipulated obesity model, by generating TRPV1 and UCP1 double knockout mice. In these mice, obesity and hypertension appeared earlier and were more severe than in mice with the knockout of UCP1 or TRPV1 alone. The knockout of TRPV1 in UCP1 knockout mice further reduced functional brown adipose tissue (BAT) generation; decreased resting oxygen consumption, heat production, and locomotor activities; and was accompanied by severe mitochondrial respiratory dysfunction in BAT. Mechanistically, TRPV1, UCP1, and LETM1 acted as a complex to maintain an appropriate mitochondrial Ca2+ level, and TRPV1 knockout caused a compensatory increase in mitochondrial Ca2+ uptake via LETM1 activation. However, the compensatory response was blocked in UCP1-/- mice, resulting in dramatically reduced mitochondrial Ca2+ uptake and higher production of ATP and oxidative stress. This study provides in vivo evidence for the critical role of BAT mitochondrial Ca2+ homeostasis in obesity-associated hypertension and indicates that the TRPV1/UCP1/LETM1 complex may be an alternative intervention target.

MicroRNA-132-3p alleviates neuron apoptosis and impairments of learning and memory abilities in Alzheimer's disease by downregulation of HNRNPU stabilized BACE1.

Alzheimer's disease (AD) is a progressive neuro-degenerative disease characterized by dementia. MicroRNAs (miRNAs) are involved in many diseases, including AD. MiR-132-3p has been identified to be downregulated in AD. In this study, we explored the effects of miR-132-3p on neuron apoptosis and impairments of learning and memory abilities. Aß1-42-stimulated SH-SY5Y cells were used as in vitro models of AD. An AD-like homocysteine (Hcy) rat model was established to evaluate the effects of miR-132-3p on AD pathogenesis in vivo. RIP, RNA pull down and luciferase reporter assays were conducted to investigate the relationship between miR-132-3p and its downstream target genes. The viability and apoptosis of SH-SY5Y cells were measured by CCK-8 and TUNEL assays. The rat spatial learning and memory abilities were accessed using Morris water maze test. Results indicated that miR-132-3p was downregulated in SH-SY5Y cells after Aß1-42 treatment and promoted cell apoptosis. Mechanistically, miR-132-3p targeted heterogeneous nuclear ribonucleoprotein U (HNRNPU). HNRNPU acted as an RNA binding protein (RBP) to regulate the mRNA stability of ß-site amyloid precursor protein cleaving enzyme 1 (BACE1). Overexpression of HNRNPU or BACE1 reversed the effects of miR-132-3p overexpression on the viability and apoptosis of Aß1-42-treated SH-SY5Y cells. In vivo experiments revealed the downregulation of miR-132-3p in the hippocampus of Hcy-treated rats. MiR-132-3p suppressed levels of apoptotic genes in hippocampus and reduced impairments of learning and memory abilities in Hcy-treated rats. In conclusion, miR-132-3p reduces apoptosis of SH-SY5Y cells and alleviates impairments of learning and memory abilities in AD rats by modulating the HNRNPU/BACE1 axis.

Analysis of soil respiration and influencing factors in a semiarid dune-meadow cascade ecosystem.

The characteristics of soil respiration (Rs) in semiarid regions are important with regard to the carbon cycle of complex underlying surfaces and estimation of carbon emissions from regional ecosystems. During the growing season (May-September 2016), in situ observations of Rs were obtained concurrently with measurements of soil bacteria (Bs), soil moisture (Ms), and soil temperature (Ts) at depths of 0-10 cm, in a dune-meadow cascade ecosystem. Results showed that Rs differences among the various ecosystems were significant (P < 0.01), the intensity of Rs in meadows was twice stronger than that in dunes. The average values of Rs presenting a declined trend follows MPA (11.19 µmol m-2 s-1) > MAF (7.75) > SSG (6.78) > SMAH (5.02) > SFAH (4.8) > FLC (4.28) > SBG (3.09). An extremely significant (p < 0.01) positive correlated power relationship can be found between Rs and Bs, which could explain 62.41%-86.56% of the variation in Rs in the various ecosystems. Field capacity and the saturated water content were the key demarcation points for the interactive relationship between Rs and Ms, which showing a significant (P < 0.05) positive correlated power relationship in dunes, in contrast, it presenting a significant (P < 0.05) negative correlated exponential relationship in meadows. Rs was positively exponentially correlated with Ts, significant (P < 0.05) in meadows and nonsignificant (P > 0.05) in dunes. Future research should be strengthened to consider multiple growing seasons experiencing various climatic conditions for accurate estimation of terrestrial carbon emissions in arid and semiarid ecosystems.

Roles of Plant Glycine-Rich RNA-Binding Proteins in Development and Stress Responses.

In recent years, much progress has been made in elucidating the functional roles of plant glycine-rich RNA-binding proteins (GR-RBPs) during development and stress responses. Canonical GR-RBPs contain an RNA recognition motif (RRM) or a cold-shock domain (CSD) at the N-terminus and a glycine-rich domain at the C-terminus, which have been associated with several different RNA processes, such as alternative splicing, mRNA export and RNA editing. However, many aspects of GR-RBP function, the targeting of their RNAs, interacting proteins and the consequences of the RNA target process are not well understood. Here, we discuss recent findings in the field, newly defined roles for GR-RBPs and the actions of GR-RBPs on target RNA metabolism.

Preparation and High Performance of Cellulose Acetate Films by Grafting with Imidazole Ionic Liquid.

Cellulose acetate (CA) grafted with imidazole ionic liquids (CA-ILs) was synthesized by reacting CA with imidazole ionic liquids ([HO2CMmim]Cl, [HO2CEtmim]Cl, and [HO2CMmim]Br) by using tetrahydrofuran (THF) as the solvent and pyridine as the catalyst. The CA and CA-IL films were fabricated by using the casting solution method. The CA-IL films exhibited good film forming ability and mechanical properties. The successful grafting of CA with imidazole ionic liquids was confirmed by Fourier transform infrared (FTIR), 1H NMR, scanning electron microscopy (SEM), and elemental analysis, and the grafting degrees were 2.24, 2.45, and 3.30%, respectively. The CO2 permeation properties of the CA-IL films were 65.5, 105.6, and 88.3 Barrer, increased up to 2.0, 3.2, and 2.7 times, respectively, as compared to pure CA (32.6 Barrer). The CO2/CH4 selectivities of the CA-IL films were 15.6, 12.6, and 19.2, increased up to 1.7, 1.4, and 2.1 times, respectively, as compared to pure CA (9.26). Therefore, it can be concluded that the imidazole ionic liquids are immensely useful for improving the gas separation performance of CA films.

Effect of Curcumin Addition on the Properties of Biodegradable Pectin/Chitosan Films.

A pectin/chitosan matrix-loaded curcumin film (PCCF) with a deep eutectic solvent (DES) as the solvent and plasticizer was prepared in this study. Different quantities of curcumin (identified as PCCF-0, PCCF-1, PCCF-2. PCCF-3) were loaded on the pectin/chitosan film in order to evaluate their effects on the film properties. Results showed that curcumin could interact with the pectin/chitosan matrix and form a complex three-dimensional network structure. PCCF could promote the thickness, tensile strength, thermal properties, antioxidant and antiseptic capacities, but deteriorate the light transmission and elongation at the same time. The addition of curcumin would change the color of the film, without significantly affecting the moisture content. The tensile strength of PCCF-3 reached the maximum value of 3.75 MPa, while the elongation decreased to 10%. Meanwhile, the water-resistance properties of PCCF-3 were significantly promoted by 8.6% compared with that of PCCF-0. Furthermore, PCCF showed remarkable sustained antioxidant activities in a dose-dependent manner. PCCF-3 could inhibit DPPH and ABTS free radicals by 58.66% and 29.07%, respectively. It also showed antiseptic capacity on fresh pork during storage. Therefore, curcumin addition could improve the barrier, mechanical, antioxidant and antiseptic properties of the polysaccharide-based film and PCCF has the potential to be used as a new kind of food packaging material in the food industry.

Home-based exercise is associated with improved cardiac functional performance in patients after acute myocardial infarction.

OBJECTIVE: To evaluate the effects of home-based exercise and physical activity on cardiac functional performance in patients after acute myocardial infarction (MI) during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: This retrospective study enrolled patients that received treatment of acute ST-segment elevation MI between and were followed-up 6 months later. The patients were divided into physically active and inactive groups based on their levels of home exercise after hospital discharge. RESULTS: A total of 78 patients were enrolled in the study: 32 were physically active and 46 were physically inactive. The baseline characteristics were comparable between the two groups. At the 6-month visit, left ventricular ejection fraction and six-minute walking test (6MWT) were significantly improved while the proportion of patients with a New York Heart Association (NYHA) functional III classification was decreased in the active patients, whereas these parameters were not significantly changed in the inactive patients. In addition, the 6MWT was greater while the proportion of patients with an NYHA III classification was lower in the active group than the inactive group at the 6-month visit. CONCLUSION: Maintaining physical activity at home was associated with improved cardiac functional performance in patients after acute MI during the COVID-19 pandemic.