Comparative Analysis of Gender-Based Differences in Behavioral Mastery, Goals, and Characteristics in Autistic Individuals: An Applied Behavior Analysis Study.

Introduction  It is widely recognized that the prevalence and diagnosis of autism spectrum disorder (ASD) are more common in males than in females. Despite this, there is a significant gap in the body of autism research that investigates gender differences for treatment effects of applied behavior analysis (ABA) across a variety of measured variables. This research aims to comprehensively evaluate gender distinctions concerning target behavioral objectives, goals, and deficit variables. Materials and methods This study analyzed retrospective data from 100 participants, including 89 juveniles and four adults, with seven cases lacking age documentation, who underwent a three-month ABA program from March 19 to June 11, 2023. The ABA program included various methodologies such as functional analysis, discrete trial training, mass trials, and naturalistic training. Data on outcome measures, including target behavioral proficiency, age, average trials to proficiency, average teaching days to proficiency, open behavioral objectives, and target trends, were collected using the "Catalyst" software (Catalyst Software Corporation, New York, NY). Participant demographics were summarized using statistical analyses for categorical (gender and race/ethnicity) and continuous variables (percentage of mastered behavioral objectives, age, average trials, average teaching days, open objectives, percentage of failed objectives during maintenance, percentage of objectives with upward, downward, and flat trends). These statistics included mean, standard deviation, median, and range and were analyzed inferentially using nine separate two-sample independent t-tests and corresponding effect sizes using Cohen's d. Results There were no statistically significant disparities based on gender (p > 0.05) across all nine variables examined: Percentage of Targets Mastered, Age, Average Trials to Mastery, Average Teaching Days to Mastery, Open Targets, Percentage of Targets Failed in Maintenance, Percentage of Targets Trending Up, Percentage of Targets Trending Down, and Percentage of Targets Trending Flat, and wide confidence intervals were detected. Conclusions  Non-significant gender differences in response to ABA treatments regarding these nine behavioral goals, mastery, and deficit variables may be relevant. They suggest that ABA treatments could be equally beneficial for both male and female autistic individuals. These results should be interpreted cautiously. The general pattern observed, characterized by broad confidence intervals, carries a degree of statistical uncertainty, which may suggest substantial gender differences. These results might question the prevailing beliefs about the variation in treatment response based on gender. This could profoundly impact clinical practices, implying that healthcare professionals should not favor one gender over another when suggesting ABA therapies. Instead, the treatment advice should be tailored to each child's unique requirements and traits, regardless of gender. The investigators expect these results to encourage additional research in this field. Comprehending the elements that affect treatment response is vital for improving treatment results and customizing care.

The CDPK-related protein kinase HvCRK2 and HvCRK4 interact with HvCML32 to negatively regulate drought tolerance in transgenic Arabidopsis thaliana.

Calcium-dependent protein kinase (CDPK) as one of calcium sensors were play important roles in stress responses. CDPK-related protein kinase (CRK) was identified as subgroup III of CDPK has been characterized in many plants, but the members and functions of CRK genes in hulless barley (Hordeum vulgare L.) has not been clarified. Here, we identified four HvCRK genes and named HvCRK1-4 according to chromosomes localization. Moreover, the physiological function of highly induced genes of HvCRK2 and HvCRK4 were investigated in drought stress tolerance by examining their overexpression transgenic lines functions generated in Arabidopsis thaliana. Under drought stress, both overexpression HvCRK2 and HvCRK4 displayed reduced drought resistance, and accompanied by higher accumulation levels of ROS. Notably, overexpression of HvCRK2 and HvCRK4 reduced sensitivity to exogenous ABA, meanwhile the expression of ABA-responsive genes in transgenic plants were down-regulated compared to the wild type in response to drought stress. Furthermore, the physically interaction of HvCRK2 and HvCRK4 with calmodulin (CaM) and calmodulin-like (CML) proteins were determined in vivo, the further results showed that HvCML32 binds to HvCRK2/4 S_TKC structural domains and negatively regulates drought tolerance. In summary, this study identified HvCRK members and indicated that HvCRK2 and HvCRK4 genes play negative roles in drought tolerance, and provide insight into potential molecular mechanism of HvCRK2 and HvCRK4 in response to drought stress.

TaMYB44-5A reduces drought tolerance by repressing transcription of TaRD22-3A in the abscisic acid signaling pathway.

MAIN CONCLUSION: TaMYB44-5A identified as a transcription factor negatively regulates drought tolerance in transgenic Arabidopsis. Drought can severely reduce yields throughout the wheat-growing season. Many studies have shown that R2R3-MYB transcription factors are involved in drought stress responses. In this study, the R2R3-MYB transcription factor MYB44-5A was identified in wheat (Triticum aestivum L.) and functionally analyzed. Three homologs of TaMYB44 were isolated, all of which localized to the nucleus. Overexpression of TaMYB44-5A reduced drought tolerance in Arabidopsis thaliana. Further analysis showed that TaMYB44-5A reduced the sensitivity of transgenic Arabidopsis to ABA. Genetic and transcriptional regulation analyses demonstrated that the expression levels of drought- and ABA-responsive genes were downregulated by TaMYB44-5A, and TaMYB44-5A directly bound to the MYB-binding site on the promoter to repress the transcription level of TaRD22-3A. Our results provide insights into a novel molecular pathway in which the R2R3-MYB transcription factor negatively regulates ABA signaling in response to drought stress.

Case report: Applied behavior analysis in a case of anomic aphasia in post-acute myocardial infarction with cardiac arrest and brain hypoxia: results of tact-training.

Purpose: Applied Behavior Analysis (ABA) tact-training was provided to an adult with post-stroke anomic aphasia, with the main purposes to improve naming of pictures, with a possible generalization to another different setting, through telehealth sessions. Method: The Multiple probe experimental design across behaviors was used. Two sets of stimuli were used (SET 1 and SET 2), including 60 laminated photos, belonging to three different categories for each set. Procedure included the baseline, the intervention phases (face-to-face and telehealth sessions), and the follow-up (1 month after the end of a tact training). Results: For both, SET 1 and SET 2, the mastery criterion (80% correct stimulus tacts, for three consecutive times, simultaneously for all categories) was achieved. No increased percentage of correct picture tacts was found for untrained items. At follow-up, the patient provided 70 to 100% correct responses. For both SET 1 and SET 2, telehealth did not modify the correct response trends. Conclusion: The results of our study seem to suggest that specific tact-training procedures might be successfully carried out in adult and elderly people with post-stroke aphasia. It also appears necessary to arrange protocols providing telehealth sessions, with benefits for both families and the health system.

The Discovery of Highly Efficient and Promising ABA Receptor Antagonists for Agricultural Applications Based on APAn Modification.

Abscisic acid (ABA) is one of the many naturally occurring phytohormones widely found in plants. This study focused on refining APAn, a series of previously developed agonism/antagonism switching probes. Twelve novel APAn analogues were synthesized by introducing varied branched or oxygen-containing chains at the C-6' position, and these were screened. Through germination assays conducted on A. thaliana, colza, and rice seeds, as well as investigations into stomatal movement, several highly active ABA receptor antagonists were identified. Microscale thermophoresis (MST) assays, molecular docking, and molecular dynamics simulation showed that they had stronger receptor affinity than ABA, while PP2C phosphatase assays indicated that the C-6'-tail chain extending from the 3' channel effectively prevented the ligand-receptor binary complex from binding to PP2C phosphatase, demonstrating strong antagonistic activity. These antagonists showed effective potential in promoting seed germination and stomatal opening of plants exposed to abiotic stress, particularly cold and salt stress, offering advantages for cultivating crops under adverse conditions. Moreover, their combined application with fluridone and gibberellic acid could provide more practical agricultural solutions, presenting new insights and tools for overcoming agricultural challenges.

Sweet Cherry Plants Prioritize Their Response to Cope with Summer Drought, Overshadowing the Defense Response to Pseudomonas syringae pv. syringae.

Disease severity and drought due to climate change present significant challenges to orchard productivity. This study examines the effects of spring inoculation with Pseudomonas syringae pv. syringae (Pss) on sweet cherry plants, cvs. Bing and Santina with varying defense responses, assessing plant growth, physiological variables (water potential, gas exchange, and plant hydraulic conductance), and the levels of abscisic acid (ABA) and salicylic acid (SA) under two summer irrigation levels. Pss inoculation elicited a more pronounced response in 'Santina' compared to 'Bing' at 14 days post-inoculation (dpi), and those plants inoculated with Pss exhibited a slower leaf growth and reduced transpiration compared to control plants during 60 dpi. During differential irrigations, leaf area was reduced 14% and 44% in Pss inoculated plants of 'Bing' and 'Santina' respectively, under well-watered (WW) conditions, without changes in plant water status or gas exchange. Conversely, water-deficit (WD) conditions led to gas exchange limitations and a 43% decrease in plant biomass compared to that under WW conditions, with no differences between inoculation treatments. ABA levels were lower under WW than under WD at 90 dpi, while SA levels were significantly higher in Pss-inoculated plants under WW conditions. These findings underscore the influence on plant growth during summer in sweet cherry cultivars that showed a differential response to Pss inoculations and how the relationship between ABA and SA changes in plant drought level responses.

Genome-Wide Identification of the Alfin-like Gene Family in Cotton (Gossypium hirsutum) and the GhAL19 Gene Negatively Regulated Drought and Salt Tolerance.

Alfin-like (AL) is a small plant-specific gene family characterized by a PHD-finger-like structural domain at the C-terminus and a DUF3594 structural domain at the N-terminus, and these genes play prominent roles in plant development and abiotic stress response. In this study, we conducted genome-wide identification and analyzed the AL protein family in Gossypium hirsutum cv. NDM8 to assess their response to various abiotic stresses for the first time. A total of 26 AL genes were identified in NDM8 and classified into four groups based on a phylogenetic tree. Moreover, cis-acting element analysis revealed that multiple phytohormone response and abiotic stress response elements were highly prevalent in AL gene promoters. Further, we discovered that the GhAL19 gene could negatively regulate drought and salt stresses via physiological and biochemical changes, gene expression, and the VIGS assay. The study found there was a significant increase in POD and SOD activity, as well as a significant change in MDA in VIGS-NaCl and VIGS-PEG plants. Transcriptome analysis demonstrated that the expression levels of the ABA biosynthesis gene (GhNCED1), signaling genes (GhABI1, GhABI2, and GhABI5), responsive genes (GhCOR47, GhRD22, and GhERFs), and the stress-related marker gene GhLEA14 were regulated in VIGS lines under drought and NaCl treatment. In summary, GhAL19 as an AL TF may negatively regulate tolerance to drought and salt by regulating the antioxidant capacity and ABA-mediated pathway.

Integrated Transcriptomic and Metabolomic Analysis Revealed Abscisic Acid-Induced Regulation of Monoterpene Biosynthesis in Grape Berries.

Monoterpenes are a class of volatile organic compounds that play crucial roles in imparting floral and fruity aromas to Muscat-type grapes. However, our understanding of the regulatory mechanisms underpinning monoterpene biosynthesis in grapes, particularly following abscisic acid (ABA) treatment, remains elusive. This study aimed to explore the impact of exogenous ABA on monoterpene biosynthesis in Ruiduhongyu grape berries by employing Headspace Solid-Phase Micro-Extraction Gas Chromatography-Mass Spectrometry (HS-SPME/GC-MS) analysis and transcriptome sequencing. The results suggested significant differences in total soluble solids (TSS), pH, and total acid content. ABA treatment resulted in a remarkable increase in endogenous ABA levels, with concentrations declining from veraison to ripening stages. ABA treatment notably enhanced monoterpene concentrations, particularly at the E_L37 and E_L38 stages, elevating the overall floral aroma of grape berries. According to the variable gene expression patterns across four developmental stages in response to ABA treatment, the E_L37 stage had the largest number of differential expressed genes (DEGs), which was correlated with a considerable change in free monoterpenes. Furthermore, functional annotation indicated that the DEGs were significantly enriched in primary and secondary metabolic pathways, underlining the relationship between ABA, sugar accumulation, and monoterpene biosynthesis. ABA treatment upregulated key genes involved in the methylerythritol phosphate (MEP) pathway, enhancing carbon allocation and subsequently impacting terpene synthesis. This study also identified transcription factors, including MYB and AP2/ERF families, potentially modulating monoterpene and aroma-related genes. Weighted gene co-expression network analysis (WGCNA) linked ABA-induced gene expression to monoterpene accumulation, highlighting specific modules enriched with genes associated with monoterpene biosynthesis; one of these modules (darkgreen) contained genes highly correlated with most monoterpenes, emphasizing the role of ABA in enhancing grape quality during berry maturation. Together, these findings provide valuable insights into the multifaceted effects of exogenous ABA on monoterpene compounds and grape berry flavor development, offering potential applications in viticulture and enology.

The White Clover TrMYB33-TrSAMS1 Module Contributes to Drought Tolerance by Modulation of Spermidine Biosynthesis via an ABA-Dependent Pathway.

Spermidine is well known to accumulate in plants exposed to drought, but the regulatory network associated with its biosynthesis and accumulation and the underlying molecular mechanisms remain unclear. Here, we demonstrated that the Trifolium repens TrMYB33 relayed the ABA signal to modulate drought-induced spermidine production by directly regulating the expression of TrSAMS1, which encodes an S-adenosylmethionine synthase. This gene was identified by transcriptome and expression analysis in T. repens. TrSAMS1 overexpression and its pTRV-VIGS-mediated silencing demonstrated that TrSAMS1 is a positive regulator of spermidine synthesis and drought tolerance. TrMYB33 was identified as an interacting candidate through yeast one-hybrid library screening with the TrSAMS1 promoter region as the bait. TrMYB33 was confirmed to bind directly to the predicted TAACCACTAACCA (the TAACCA MYB binding site is repeated twice in tandem) within the TrSAMS1 promoter and to act as a transcriptional activator. Additionally, TrMYB33 contributed to drought tolerance by regulating TrSAMS1 expression and modulating spermidine synthesis. Additionally, we found that spermidine accumulation under drought stress depended on ABA and that TrMYB33 coordinated ABA-mediated upregulation of TrSAMS1 and spermidine accumulation. This study elucidated the role of a T. repens MYB33 homolog in modulating spermidine biosynthesis. The further exploitation and functional characterization of the TrMYB33-TrSAMS1 regulatory module can enhance our understanding of the molecular mechanisms responsible for spermidine accumulation during drought stress.

A key ABA biosynthetic gene OsNCED3 is a positive regulator in resistance to Nilaparvata lugens in Oryza sativa.

The gene encoding 9-cis-epoxycarotenoid dioxygenase 3 (NCED3) functions in abscisic acid (ABA) biosynthesis, plant growth and development, and tolerance to adverse temperatures, drought and saline conditions. In this study, three rice lines were used to explore the function of OsNCED3, these included an OsNCED3-overexpressing line (OsNCED3-OE), a knockdown line (osnced3-RNAi) and wild-type rice (WT). These rice lines were infested with the brown plant hopper (BPH; Nilaparvata lugens) and examined for physiological and biochemical changes, hormone content, and defense gene expression. The results showed that OsNCED3 activated rice defense mechanisms, which led to an increased defense enzyme activity of superoxide dismutase, peroxidase, and polyphenol oxidase. The overexpression of OsNCED3 decreased the number of planthoppers and reduced oviposition and BPH hatching rates. Furthermore, the overexpression of OsNCED3 increased the concentrations of jasmonic acid, jasmonyl-isoleucine and ABA relative to WT rice and the osnced3-RNAi line. These results indicate that OsNCED3 improved the stress tolerance in rice and support a role for both jasmonates and ABA as defense compounds in the rice-BPH interaction.

Research Progress in the Regulation of the ABA Signaling Pathway by E3 Ubiquitin Ligases in Plants.

E3 ubiquitin ligases (UBLs), as enzymes capable of specifically recognizing target proteins in the process of protein ubiquitination, play crucial roles in regulating responses to abiotic stresses such as drought, salt, and temperature. Abscisic acid (ABA), a plant endogenous hormone, is essential to regulating plant growth, development, disease resistance, and defense against abiotic stresses, and acts through a complex ABA signaling pathway. Hormone signaling transduction relies on protein regulation, and E3 ubiquitin ligases play important parts in regulating the ABA pathway. Therefore, this paper reviews the ubiquitin-proteasome-mediated protein degradation pathway, ABA-related signaling pathways, and the regulation of ABA-signaling-pathway-related genes by E3 ubiquitin ligases, aiming to provide references for further exploration of the relevant research on how plant E3 ubiquitin ligases regulate the ABA pathway.

Developmental and heritable genetic defects induced in mice by municipal landfill leachate.

Environmental pollution by solid waste leachate is a serious environmental and public health concern. Leachate contamination and pollution of environmental matrices have been reported, but no report of embryotoxic and developmental defects, and heritable transfer of leachate-induced toxicity in mice. We investigated the ability of Aba-Eku landfill leachate to induce embryonic malformations, developmental toxicity, and germline and somatic DNA damage in the F1 of exposed pregnant mice. Pregnant mice (n = 100) were randomly distributed into 5 experimental groups of 20 animals/group and exposed to 0.2 mL of 5-75% concentrations of the leachate (v/v; Aba-Eku landfill leachate: distilled water) by daily gavage from gestational day (GD) zero to postnatal day (PND) 21. A similar treatment was given to pregnant female mice administered with distilled water (negative control). At GD 18, ten dams from the treatment and control groups were sacrificed by cervical dislocation after which the embryos were collected from the uterus for analyses of fetal morphometric and skeletal metamers respectively. We then monitored the developmental conditions of F1 mice from the remaining ten dams until they were weaned at PND 21 and sacrificed at PND 56 and PND 98 for bone marrow micronucleus and spermiogram analyses respectively. We also analyzed the leachate for inorganic and organic pollutants and calculated the Leachate Pollution Index (LPI). The leachate reduced maternal and fetal birth weight and increased fetal mortality and postnatal appearance of physiological markers in the F1 mice. There was a significant increase (p < 0.05) in the frequency of fetal skeletal malformations, micronucleated polychromatic erythrocytes, and apparent decline of epididymal sperm parameters. The concentrations of the inorganic and organic pollutants, and the LPI exceeded standard limits. Exposure of pregnant female mice to Aba-Eku landfill leachate caused embryonic defects and heritable DNA damage in subsequent generations.

Reactive Oxygen Species (ROS) Measurement in Arabidopsis Guard Cells in Response to Biotic and Abiotic Stresses.

One of the major plant stress level indicators is reactive oxygen species (ROS). They have been known to play a central role in regulating plant responses to various environmental stresses. This book chapter specifically covers abiotic stress induced by a drought hormone abscisic acid and biotic stress induced by Pseudomonas syringe DC3000 on single cell-type guard cells. We describe in detail the measurement of ROS production starting from sample preparation to data analysis by fluorescence intensity acquisition using ImageJ software. We discussed the problems faced while performing the experiment and addressed how to overcome them by providing specific guidelines to ensure high quality repeatable data.

OsJRL negatively regulates rice cold tolerance via interfering phenylalanine metabolism and flavonoid biosynthesis.

The identification of new genes involved in regulating cold tolerance in rice is urgent because low temperatures repress plant growth and reduce yields. Cold tolerance is controlled by multiple loci and involves a complex regulatory network. Here, we show that rice jacalin-related lectin (OsJRL) modulates cold tolerance in rice. The loss of OsJRL gene functions increased phenylalanine metabolism and flavonoid biosynthesis under cold stress. The OsJRL knock-out (KO) lines had higher phenylalanine ammonia-lyase (PAL) activity and greater flavonoid accumulation than the wild-type rice, Nipponbare (NIP), under cold stress. The leaves had lower levels of reactive oxygen species (ROS) and showed significantly enhanced cold tolerance compared to NIP. In contrast, the OsJRL overexpression (OE) lines had higher levels of ROS accumulation and showed lower cold tolerance than NIP. Additionally, the OsJRL KO lines accumulated more abscisic acid (ABA) and jasmonic acid (JA) under cold stress than NIP. The OsJRL OE lines showed increased sensitivity to ABA compared to NIP. We conclude that OsJRL negatively regulates the cold tolerance of rice via modulation of phenylalanine metabolism and flavonoid biosynthesis.

Heat-stress-responsive HvHSFA2e gene regulates the heat and drought tolerance in barley through modulation of phytohormone and secondary metabolic pathways.

KEY MESSAGE: The heat stress transcription factor HSFA2e regulates both temperature and drought response via hormonal and secondary metabolism alterations. High temperature and drought are the primary yield-limiting environmental constraints for staple food crops. Heat shock transcription factors (HSF) terminally regulate the plant abiotic stress responses to maintain growth and development under extreme environmental conditions. HSF genes of subclass A2 predominantly express under heat stress (HS) and activate the transcriptional cascade of defense-related genes. In this study, a highly heat-inducible HSF, HvHSFA2e was constitutively expressed in barley (Hordeum vulgare L.) to investigate its role in abiotic stress response and plant development. Transgenic barley plants displayed enhanced heat and drought tolerance in terms of increased chlorophyll content, improved membrane stability, reduced lipid peroxidation, and less accumulation of ROS in comparison to wild-type (WT) plants. Transcriptome analysis revealed that HvHSFA2e positively regulates the expression of abiotic stress-related genes encoding HSFs, HSPs, and enzymatic antioxidants, contributing to improved stress tolerance in transgenic plants. The major genes of ABA biosynthesis pathway, flavonoid, and terpene metabolism were also upregulated in transgenics. Our findings show that HvHSFA2e-mediated upregulation of heat-responsive genes, modulation in ABA and flavonoid biosynthesis pathways enhance drought and heat stress tolerance.

The superior allele LEA12OR in wild rice enhances salt tolerance and yield.

Soil salinity has negative impacts on food security and sustainable agriculture. Ion homeostasis, osmotic adjustment and reactive oxygen species scavenging are the main approaches utilized by rice to resist salt stress. Breeding rice cultivars with high salt tolerance (ST) and yield is a significant challenge due to the lack of elite alleles conferring ST. Here, we report that the elite allele LEA12OR, which encodes a late embryogenesis abundant (LEA) protein from the wild rice Oryza rufipogon Griff., improves osmotic adjustment and increases yield under salt stress. Mechanistically, LEA12OR, as the early regulator of the LEA12OR-OsSAPK10-OsbZIP86-OsNCED3 functional module, maintains the kinase stability of OsSAPK10 under salt stress, thereby conferring ST by promoting abscisic acid biosynthesis and accumulation in rice. The superior allele LEA12OR provides a new avenue for improving ST and yield via the application of LEA12OR in current rice through molecular breeding and genome editing.

The U-Box E3 Ubiquitin Ligase PUB35 Negatively Regulates ABA Signaling through AFP1-mediated Degradation of ABI5.

Abscisic acid (ABA) signaling is crucial for plant responses to various abiotic stresses. The Arabidopsis (Arabidopsis thaliana) transcription factor ABA INSENSITIVE 5 (ABI5) is a central regulator of ABA signaling. ABI5 BINDING PROTEIN 1 (AFP1) interacts with ABI5 and facilitates its 26S-proteasome-mediated degradation, although the detailed mechanism has remained unclear. Here, we report that an ABA-responsive U-box E3 ubiquitin ligase, PLANT U-BOX 35 (PUB35), physically interacts with AFP1 and ABI5. PUB35 directly ubiquitinated ABI5 in a bacterially reconstituted ubiquitination system and promoted ABI5 protein degradation in vivo. ABI5 degradation was enhanced by AFP1 in response to ABA treatment. Phosphorylation of the T201 and T206 residues in ABI5 disrupted the ABI5-AFP1 interaction and affected the ABI5-PUB35 interaction and PUB35-mediated degradation of ABI5 in vivo. Genetic analysis of seed germination and seedling growth showed that pub35 mutants were hypersensitive to ABA as well as to salinity and osmotic stresses, whereas PUB35 overexpression lines were hyposensitive. Moreover, abi5 was epistatic to pub35, whereas the pub35-2 afp1-1 double mutant showed a similar ABA response to the two single mutants. Together, our results reveal a PUB35-AFP1 module involved in fine-tuning ABA signaling through ubiquitination and 26S-proteasome-mediated degradation of ABI5 during seed germination and seedling growth.

Abscisic Acid Induces DNA Methylation Alteration in Genes Related to Berry Ripening and Stress Response in Grape (Vitis vinifera L).

Abscisic acid (ABA) is a major regulator of nonclimacteric fruit ripening, with its processes involving epigenetic mechanisms. It remains unclear whether DNA methylation is associated with ABA-regulated ripening. In this study, we investigated the patterns of DNA methylation and gene expression following ABA treatment in grape berries by using whole-genome bisulfite sequencing and RNA-sequencing. ABA application changed global DNA methylation in grapes. The hyper-/hypo-differently methylated regions were enriched in defense-related metabolism, degreening processes, or ripening-related metabolic pathways. Many differentially expressed genes showed an alteration in DNA methylation after ABA treatment. Specifically, ten downregulated genes with hypermethylation in promoters were involved in the ripening process, ABA homeostasis/signaling, and stress response. Nine upregulated genes exhibiting hypo-methylation in promoters were related to the ripening process and stress response. These findings demonstrated ABA-induced DNA alteration of ripening related and stress-responsive genes during grape ripening, which provides new insights of the epigenetic regulation of ABA on fruit ripening.

Apple Glycosyltransferase MdUGT73AR4 Glycosylates ABA to Regulate Stomatal Movement Involved in Drought Stress.

Abscisic acid (ABA) is a drought-stress-responsive hormone that plays an important role in the stomatal activity of plant leaves. Currently, ABA glycosides have been identified in apples, but their glycosyltransferases for glycosylation modification of ABA are still unidentified. In this study, the mRNA expression of glycosyltransferase gene MdUGT73AR4 was significantly up-regulated in mature apple leaves which were treated in drought stress by Real-Time PCR. It was hypothesised that MdUGT73AR4 might play an important role in drought stress. In order to further characterise the glycosylation modification substrate of glycosyltransferase MdUGT73AR4, we demonstrated through in vitro and in vivo functional validation that MdUGT73AR4 can glycosylate ABA. Moreover, the overexpression lines of MdUGT73AR4 significantly enhance its drought stress resistance function. We also found that the adversity stress transcription factor AREB1B might be an upstream transcription factor of MdUGT73AR4 by bioinformatics, EMSA, and ChIP experiments. In conclusion, this study found that the adversity stress transcription factor AREB1B was significantly up-regulated at the onset of drought stress, which in turn positively regulated the downstream glycosyltransferase MdUGT73AR4, causing it to modify ABA by mass glycosylation and promoting the ABA synthesis pathway, resulting in the accumulation of ABA content, and displaying a stress-resistant phenotype.

SOS2-AFP2 module regulates seed germination by inducing ABI5 degradation in response to salt stress in Arabidopsis.

Soil salinity pose a significant challenge to global agriculture, threatening crop yields and food security. Understanding the salt tolerance mechanisms of plants is crucial for improving their survival under salt stress. AFP2, a negative regulator of ABA signaling, has been shown to play a crucial role in salt stress tolerance during seed germination. Mutations in AFP2 gene lead to increased sensitivity to salt stress. However, the underline mechanisms by which AFP2 regulates seed germination under salt stress remain elusive. In this study, we identified a protein interaction between AFP2 and SOS2, a Ser/Thr protein kinase known to play a critical role in salt stress response. Using a combination of genetic, biochemical, and physiological approaches, we investigated the role of the SOS2-AFP2 module in regulating seed germination under salt stress. Our findings reveal that SOS2 physically interacts with AFP2 and stabilizes it, leading to the degradation of the ABI5 protein, a negative transcription factor in seed germination under salt stress. This study sheds light on previously unknown connections within salt stress and ABA signaling, paving the way for novel strategies to enhance plant resilience against environmental challenges.