Parental Lines Research Articles

High water use efficiency due to maintenance of photosynthetic capacity in sorghum under water stress.

Environmental change requires more crop production per water use to meet the rising global food demands. However, improving crop intrinsic water use efficiency (iWUE) usually comes at the expense of carbon assimilation. Sorghum is a key crop in many vulnerable agricultural systems with higher tolerance to water stress (WS) than most widely planted crops. To investigate physiological controls on iWUE and its inheritance in sorghum we screened 89 genotypes selected based on inherited haplotypes from an elite or five exotics lines, containing a mix of geographical origins and dry vs. milder climates, which included different aquaporin (AQP) alleles. We found significant variation among key highly heritable gas exchange and hydraulic traits, with some being significantly affected by variation in haplotypes among parental lines. Plants with a higher proportion of the non-stomatal component of iWUE still maintained iWUE under WS by maintaining photosynthetic capacity, independently of reduction in leaf hydraulic conductance. Haplotypes associated with two AQPs (SbPIP1.1 and SbTIP3.2) influenced iWUE and related traits. These findings expand the range of traits that bridge the trade-off between iWUE and productivity in C4 crops, and provide possible genetic regions that can be targeted for breeding.

Molecular mechanisms of heterosis under drought stress in maize hybrids Zhengdan7137 and Zhengdan7153

Maize is one of the most successful crops in utilizing heterosis which significantly improves maize stresses resistance and yield. Drought is a destructive abiotic stress that significantly reduces crop yield, particularly in maize. Drought stress and re-watering frequently occur during the growth and development of maize; however, the molecular mechanisms of heterosis under drought stress and re-watering have rarely been systematically investigated. Zhengdan7137 and Zhengdan7153 are two maize hybrid varieties with robust heterosis, and separately belongs to the SS×NSS and Reid×Tangsipingtou heterotic groups. 54 transcriptomes of these two hybrids and their parental inbred lines were analyzed under well-watering (WW), water-deficit (WD), and re-watering (RW) conditions using RNA-Seq. In this study, we identified 3,411 conserved drought response genes (CDRGs) and 3,133 conserved re-watering response genes (CRRGs) between Zhengdan7137 and Zhengdan7153. When comparing CDRGs and CRRGs to overdominance and underdominance genes, we identified 303 and 252 conservative drought response overdominance genes (DODGs) and underdominance genes (DUDGs), respectively, and 165 and 267 conservative re-watering response overdominance genes (RODGs) and underdominance genes (RUDGs), respectively. DODGs are involved in stress response-related processes, such as L-phenylalanine metabolism, carbohydrate metabolism, and heat response, whereas DUDGs are associated with glucose metabolism, pentose-phosphate shunt, and starch metabolism. RODGs and RUDGs contribute to the recovery of hybrids from drought stress by upregulating cell propagation and photosynthesis processes, and repressing stress response processes, respectively. It indicated overdominant and underdominant genes conservatively contributed to hybrid heterosis under drought stress. These results deepen our understanding of the molecular mechanisms of drought resistance, uncover conservative molecular mechanisms of heterosis under drought stress and re-watering, and provide potential targets for improving drought resistance in maize.

Genetic Analysis for Seed Yield and Yield‐Related Traits in Tepary Bean (Phaseolus acutifolius A. Gray) Under Drought‐Stress and Non‐stress Conditions

ABSTRACTTepary bean (Phaseolus acutifolius A. Gray) is an under‐utilized genetic resource with significant potential for food security and stress tolerance breeding. Expanding its cultivation in southern Africa requires high‐yielding, locally adapted and drought‐tolerant varieties. This study determined the combining ability and genetic components for seed yield and related traits in tepary bean genotypes under non‐stress (NS) and drought‐stress (DS) conditions. Seven parents were selected through rigorous phenotyping and crossed using a half‐diallel design. The 7 parents and 21 F2 progenies were evaluated in 2021/2022 season at Kasinthula and Bunda sites in Malawi under NS and DS conditions using a 4 × 7 lattice design with three replications. The specific combining ability (SCA) × location interaction effect was significant (p < 0.05) for DTF, NPP, and SY, suggesting that the genetic effects of crosses were influenced by the test locations. General combining ability (GCA) and SCA mean squares were significant for the number of seeds per pod (NSP) and SY under DS conditions, indicating both additive and non‐additive gene effects. Baker's ratio (BR) > 0.50 for NPP and NSP under DS conditions suggested a preponderance of additive gene effects. G40145, G40148 and G40150 parental lines were good combiners for NPP and SY. The F2 families from crosses such as Zimbabwe landrace/G40138, Zimbabwe landrace/G40150, G40059/G40145, G40059/G40148, G40138/G40150 and G40145/G40150 were identified as best specific combiners, with enhanced SY of 1.67 t/ha under DS conditions. The study recommends advancing high‐performing early‐generation families for selection across representative environments to facilitate variety release and commercialization.

Development of KISS1 knockout pigs is characterized by hypogonadotropic hypogonadism, normal growth, and reduced skatole.

Kisspeptin is a major regulator of gonadotropin secretion in pigs. Previously, CRISPR/Cas9 knockout of KISS1 was used to develop a mosaic parental line of pigs to generate offspring that would not need castration due to loss of kisspeptin. The current goal was to characterize growth and reproductive development of F1 pigs from this parental line. Body weights, gonadotropin concentrations and gonadal development were measured from birth through development (boars to 220 d of age, n = 42; gilts to 160 d of age, n = 36). Testosterone, skatole, and androstenone were also measured in boars. Blood samples were collected by jugular venipuncture for quantification of serum hormones, gonadal tissues collected for gross morphology and histology, and a fat biopsy collected (boars) for skatole and androstenone analysis. Body weight did not differ with genotype. There were no differences between KISS1+/+ and heterozygote KISS1+/- animals for most parameters measured. Gonadotropin concentrations were reduced in KISS1-/- boars and gilts compared with KISS1+/+ and KISS1+/- animals (P < 0.05). Concentrations of testosterone in serum and both androstenone and skatole in adipose were less in KISS1-/- boars than in KISS1+/+ and KISS1+/- boars (P < 0.05). Hypogonadism was in all KISS1-/- gilts and boars. These data indicate that knocking out KISS1 causes hypogonadotropic hypogonadism but does not negatively affect growth in pigs. Only one KISS1 allele is needed for normal gonadotropin secretion and gonadal development, and accumulation of compounds in adipose leading to boar taint.

TMT-Based Quantitative Proteomic Profiling of Human Esophageal Cancer Cells Reveals the Potential Mechanism and Potential Therapeutic Targets Associated With Radioresistance.

The recurrence of esophageal squamous cell carcinoma (ESCC) in radiation therapy treatment presents a complex challenge due to its resistance to radiation. However, the mechanism underlying the development of radioresistance in ESCC remains unclear. In this study, we aim to uncover the mechanisms underlying radioresistance in ESCC cells and identify potential targets for radiosensitization. We established two radio-resistant cell lines, TE-1R and KYSE-150R, from the parental ESCC cell lines TE-1 and KYSE-150 through fractionated irradiation. A TMT-based quantitative proteomic profiling approach was applied to identify changes in protein expression patterns. Cell Counting Kit-8, colony formation, γH2AX foci immunofluorescence and comet assays were utilized to validate our findings. The downstream effectors of the DNA repair pathway were confirmed using an HR/NHEJ reporter assay and Western blot analysis. Furthermore, we evaluated the expression of potential targets in ESCC tissues through immunohistochemistry combined with mass spectrometry. Over 2,000 proteins were quantitatively identified in the ESCC cell lysates. A comparison with radio-sensitive cells revealed 61 up-regulated and 14 down-regulated proteins in the radio-resistant cells. Additionally, radiation treatment induced 24 up-regulated and 12 down-regulated proteins in the radio-sensitive ESCC cells. Among the differentially expressed proteins, S100 calcium binding protein A6 (S100A6), glutamine gamma-glutamyltransferase 2 (TGM2), glycogen phosphorylase, brain form (PYGB), and Thymosin Beta 10 (TMSB10) were selected for further validation studies as they were found to be over-expressed in the accumulated radio-resistant ESCC cells and radio-resistant cells. Importantly, high S100A6 expression showed a positive correlation with cancer recurrence in ESCC patients. Our results suggest that several key proteins, including S100A6, TGM2, and PYGB, play a role in the development of radioresistance in ESCC. Our results revealed that several proteins including Protein S100-A6 (S100A6), Protein-glutamine gamma-glutamyltransferase 2 (TGM2), Glycogen phosphorylase, brain form (PYGB) were involved in radio-resistance development. These proteins could potentially serve as biomarkers for ESCC radio-resistance and as therapeutic targets to treat radio-resistant ESCC cells.

7831 Unveiling Drug Resistance Mechanisms In Triple-Positive Breast Cancer: Insights From Long-Term Estrogen Deprivation Models And Innovative Mutation Detection Strategies

Abstract Disclosure: S. Bahnassy: None. H.S. Andrews: None. L. Jin: None. B.F. Kohrn: None. S. Tam: None. D. Mobin: None. Y.J. Dunn: None. M. Balachandran: None. M. Podar: None. W. He: None. M.D. McCoy: None. R.A. Beckman: Consulting Fee; Self; AstraZeneca, Boehringer Ingelheim. Other; Self; Chief Scientific Officer of OncoMind, LLC, which owns patents on dynamic precision medicine. R.B. Riggins: None. Compelling evidence from preclinical and clinical data suggests that triple-positive (TP; HER2+/HR+) breast cancer (BC) has lower response rates to HER2-targeted therapy and a higher risk of recurrence to endocrine therapy (ET) than HER2+/HR−. Molecular mechanisms underpinning drug resistance in TP-BC are poorly understood, thereby limiting our ability to improve patient outcomes and prevent metastatic progression. In our recent publication, we established and characterized long-term estrogen deprivation (LTED) ET-resistant (ETR) TP-BC models that mimic resistance to aromatase inhibitors without using genetic manipulation approaches. We reported intrinsic subtype shifts towards non-luminal phenotypes, metabolic reprogramming, and acquiring mutations in genes encoding for transcription factors and chromatin modifiers, as potential mechanisms of ETR in our LTED models. The emergence of drug-resistant mutator subclones under treatment-induced selective pressures, coupled with limitations in shallow-depth whole genome sequencing coverage, highlight an unmet need to develop a strategy for visually monitoring, capturing, and mapping resistant subclones through a mutational phenotypic screen, an approach offering valuable insights for optimizing treatment schedules. To address this, we developed and applied an innovative dual fluorescence mutation detection system to detect mutator cells expressing both mCherry and green fluorescence protein (GFP). First, we validated if our system is working properly. Compared to parental cells, transduced BT-474 and MDA-MB-361 LTEDs showed a drastic increase in GFP+ cells, suggesting the presence of resistant mutator cells. Consistent with the increase in GFP signal, TP-LTEDs showed increased mutation number and frequency in two Duplex Sequencing targeted capture panels (neutral loci and DNA polymerase-focused), used to perform ultra-deep, highly accurate sequencing. We then treated parental cells with single, dual, and triple combinations of anti-HER2, ET and CDK4/6 inhibitors to track the emergence of GFP+ mutator cells. Nine-day treatments with triple combinatorial therapies were best at inhibiting the growth of both BT-474 and MDA-MB-361 parental cell lines, compared to single- and double-agent targeted therapies. However, no GFP signal was detected within treated cells, suggesting that longer treatment durations are needed for drug-resistance mutator subclones to be discovered. Ongoing studies monitoring TP-drug resistance mutator subclones with long-term conventional targeted-therapies will improve our understanding of drug resistance mechanisms in this understudied subtype of BC. Importantly, these studies will enable dynamic precision medicine simulations to empower for a more tailored and effective therapeutic administration to prevent drug resistance and metastatic progression of TP-BC. Presentation: 6/3/2024

7831 Unveiling Drug Resistance Mechanisms in Triple-Positive Breast Cancer: Insights from Long-Term Estrogen Deprivation Models and Innovative Mutation Detection Strategies

Abstract Disclosure: S. Bahnassy: None. H.S. Andrews: None. L. Jin: None. B.F. Kohrn: None. S. Tam: None. D. Mobin: None. Y.J. Dunn: None. M. Balachandran: None. M. Podar: None. W. He: None. M.D. McCoy: None. R.A. Beckman: Consulting Fee; Self; AstraZeneca, Boehringer Ingelheim. Other; Self; Chief Scientific Officer of OncoMind, LLC, which owns patents on dynamic precision medicine. R.B. Riggins: None. Compelling evidence from preclinical and clinical data suggests that triple-positive (TP; HER2+/HR+) breast cancer (BC) has lower response rates to HER2-targeted therapy and a higher risk of recurrence to endocrine therapy (ET) than HER2+/HR−. Molecular mechanisms underpinning drug resistance in TP-BC are poorly understood, thereby limiting our ability to improve patient outcomes and prevent metastatic progression. In our recent publication, we established and characterized long-term estrogen deprivation (LTED) ET-resistant (ETR) TP-BC models that mimic resistance to aromatase inhibitors without using genetic manipulation approaches. We reported intrinsic subtype shifts towards non-luminal phenotypes, metabolic reprogramming, and acquiring mutations in genes encoding for transcription factors and chromatin modifiers, as potential mechanisms of ETR in our LTED models. The emergence of drug-resistant mutator subclones under treatment-induced selective pressures, coupled with limitations in shallow-depth whole genome sequencing coverage, highlight an unmet need to develop a strategy for visually monitoring, capturing, and mapping resistant subclones through a mutational phenotypic screen, an approach offering valuable insights for optimizing treatment schedules. To address this, we developed and applied an innovative dual fluorescence mutation detection system to detect mutator cells expressing both mCherry and green fluorescence protein (GFP). First, we validated if our system is working properly. Compared to parental cells, transduced BT-474 and MDA-MB-361 LTEDs showed a drastic increase in GFP+ cells, suggesting the presence of resistant mutator cells. Consistent with the increase in GFP signal, TP-LTEDs showed increased mutation number and frequency in two Duplex Sequencing targeted capture panels (neutral loci and DNA polymerase-focused), used to perform ultra-deep, highly accurate sequencing. We then treated parental cells with single, dual, and triple combinations of anti-HER2, ET and CDK4/6 inhibitors to track the emergence of GFP+ mutator cells. Nine-day treatments with triple combinatorial therapies were best at inhibiting the growth of both BT-474 and MDA-MB-361 parental cell lines, compared to single- and double-agent targeted therapies. However, no GFP signal was detected within treated cells, suggesting that longer treatment durations are needed for drug-resistance mutator subclones to be discovered. Ongoing studies monitoring TP-drug resistance mutator subclones with long-term conventional targeted-therapies will improve our understanding of drug resistance mechanisms in this understudied subtype of BC. Importantly, these studies will enable dynamic precision medicine simulations to empower for a more tailored and effective therapeutic administration to prevent drug resistance and metastatic progression of TP-BC. Presentation: 6/3/2024

6889 Potential Impact of Parental Origin of Inheritance in Presentation of Familial Partial Lipodystrophy

Abstract Disclosure: D. Gilio: None. M.C. Foss de Freitas: Advisory Board Member; Self; PTC Therapeutics. Speaker; Self; Amryt. O. Besci: None. M. Celik Guler: None. A. Neidert: None. I. Yildirim: None. B. Akinci: Advisory Board Member; Self; Amryt. Consulting Fee; Self; Regeneron Pharmaceuticals, Alnylam Pharmaceuticals, Amryt, AstraZeneca, Boehringer Ingelheim, Lilly, MSD, Novartis Pharmaceuticals, Novo Nordisk, Sanofi-Aventis, Servier, Third Rock Ventures. E.A. Oral: Advisory Board Member; Self; Amryt, Regeneron Pharmaceuticals. Consulting Fee; Self; Regeneron Pharmaceuticals, Amryt, Third Rock Ventures. Grant Recipient; Self; Regeneron Pharmaceuticals, Amryt. Research Investigator; Self; Novo Nordisk, Fractyl, Ionis Pharmaceuticals Inc., GI Dynamics, Rhythm Pharmaceuticals. Other; Self; Amryt. Background: Familial partial lipodystrophy Type 2 (FPLD2) caused by autosomal dominant LMNA variants is characterized by partial loss of subcutaneous adipose tissue in the limbs, trunk, and gluteal region with accumulation in other parts of the body, such as the face and neck. It is usually associated with different degrees of insulin resistance and hypertriglyceridemia and body composition patterns. We wanted to know the contributing factors for the different metabolic abnormalities and body composition presentations of FPLD2. We hypothesized that parental inheritance line may be a contributory factor to the expression of the metabolic phenotype and body composition characteristics. Methods: We retrospectively collected clinical data of 77 FPLD2 cases from the Divisions of Metabolism and Endocrinology of 3 different sites: the University of Michigan, the University of São Paulo and The Turkish Lipodystrophy Study Group (TuLip). We further selected 53 published cases curated from 15 studies in the literature. For inclusion of the studies, we used web search tools including PubMed, OMIM and Google Scholar. Only patients where we could assess the genetic inheritance were included in this study. Data collected included demographic information, medical history and laboratory results. Results: 79 patients inherited the LMNA variant from the mother (Group 1; 18 males and 61 females), and 51 patients inherited it from the father (Group 2; 14 males and 37 females). The median age at lipodystrophy diagnosis was lower in Group 1 than in Group 2. Diabetes was reported in more than half of the groups; however, the prevalence rates were not significantly different. The mean age (± SEM) at first diagnosis of diabetes was 30 ± 15 years in Group 1 and 32 ± 11 years in Group 2; the microvascular complications were present in 8 patients with diabetes in Group 1 (36.3%) and in 5 patients in Group 2 (23.8%). Both groups' mean triglycerides levels were &amp;gt;150 mg/dL, with a trend of higher triglycerides in Group 2 than in Group 1. Episodes of acute pancreatitis were identified in 9 patients (19.5%) of Group 1 and 10 patients (31.2%) of Group 2; however, patients in Group 1 showed 1.7 episodes of pancreatitis per person while Group 2 showed 8.1 episodes per person on average. The fatty liver disease was the most common liver abnormality identified and it seemed to be more frequent in Group 2 than in Group 1. There was no difference between the two groups in relation to the body mass index (BMI) and the ratio of percent fat mass of the trunk to percent fat mass of the legs (FMR); however, the DEXA (dual x-ray absorptiometry) showed a higher total fat mass in Group 1 compared to Group 2 (22.2 versus 17.3 Kg, p=0.040) in the presence of comparable total lean mass. Conclusion: Our data suggest that there is a difference in body fat mass according to the genetic inheritance, however the metabolic impact is not completely clear and require more detailed analysis. Presentation: 6/1/2024

Non-additive expression genes play a critical role in leaf vein ratio heterosis in Nicotiana tabacum L.

Heterosis, recognized for improving crop performance, especially in the first filial (F1) generation, remains an area of significant study in the tobacco industry. The low utilization of leaf veins in tobacco contributes to economic inefficiency and resource waste. Despite the positive impacts of heterosis on crop genetics, investigations into leaf-vein ratio heterosis in tobacco have been lacking. Understanding the mechanisms underlying negative heterosis in leaf vein ratio at the molecular level is crucial for advancing low vein ratio leaf breeding research. This study involved 12 hybrid combinations and their parental lines to explore heterosis associated with leaf vein ratios. The hybrids displayed diverse patterns of positive or negative leaf vein ratio heterosis across different developmental stages. Notably, the F1 hybrid (G70 × Qinggeng) consistently exhibited substantial negative heterosis, reaching a maximum of -19.79% 80 days after transplanting. A comparative transcriptome analysis revealed that a significant proportion of differentially expressed genes (DEGs), approximately 39.04% and 23.73%, exhibited dominant and over-dominant expression patterns, respectively. These findings highlight the critical role of non-additive gene expression, particularly the dominance pattern, in governing leaf vein ratio heterosis. The non-additive genes, largely associated with various GO terms such as response to abiotic stimuli, galactose metabolic process, plant-type cell wall organization, auxin-activated signaling pathway, hydrolase activity, and UDP-glycosyltransferase activity, were identified. Furthermore, KEGG enrichment analysis unveiled their involvement in phenylpropanoid biosynthesis, galactose metabolism, plant hormone signal transduction, glutathione metabolism, MAPK signaling pathway, starch, and sucrose metabolism. Among the non-additive genes, we identified some genes related to leaf development, leaf size, leaf senescence, and cell wall extensibility that showed significantly lower expression in F1 than in its parents. These results indicate that the non-additive expression of genes plays a key role in the heterosis of the leaf vein ratio in tobacco. This study marks the first exploration into the molecular mechanisms governing leaf vein ratio heterosis at the transcriptome level. These findings significantly contribute to understanding leaf vein ratios in tobacco breeding strategies.

Phenotypic, genetic, variation, and molecular function of CaMYB113 in pepper (Capsicum annuum L.).

Pepper (Capsicum annuum L.) is widely consumed vegetables worldwide, and F1 hybrids are highly sought after in the pepper seed industry. However, studies on gene mutations affecting the color of cotyledon are rare, and the same is true for peppers. In this study, a segregating population was developed by crossing the pepper accession 21C1344 with purple cotyledon and accession 21C912 with green cotyledon. Initially, a target genomic region was identified by screening polymorphic SSR markers distributed across 12 chromosomes. Subsequently, polymorphic markers were developed based on resequencing data from the two parental lines, and genetic linkage analysis was performed. This approach ultimately identified Capana10g001433 (CaMYB113) as the candidate gene responsible for the purple cotyledons. The gene mutation type in 21C912 represents a new mutation type distinct from the reported missense mutation types, and this mutation affects the biosynthesis of anthocyanins. Virus-induced gene silencing (VIGS) of CaMYB113 substantially decreased anthocyanin accumulation in the cotyledons. Subsequent overexpression of CaMYB113 resulted in purple callus and leaves of pepper, and changed the expression levels of downstream genes involved in anthocyanin synthesis. Yeast one-hybrid and dual-luciferase transient expression assays demonstrated the binding of CaMYB113 to anthocyanin biosynthesis-related genes, thereby regulating anthocyanin accumulation in pepper cotyledons.

Identification of quantitative trait loci for lodging and related agronomic traits in soybean (Glycine max [L.] Merr.)

BackgroundLodging, a crucial agronomic trait linked to soybean yield, poses a significant challenge in soybean production. Nevertheless, there has been less research on soybean lodging compared to other important agronomic traits, hindering progress in breeding high-yield soybeans. Our goals were to investigate lodging, pinpoint quantitative trait loci (QTL) linked to lodging, and forecast potential candidate genes linked to this trait. To achieve this, we employed a recombinant inbred line (RIL) population derived from a cross between Guizao 1 and B13 (GB) across various environments.ResultsThe lodging score of the RIL population was found to be significantly positively correlated with flowering time, maturity time, plant height, number of main stem nodes, stem diameter, and internode length, with correlation coefficients ranging from 0.457 to 0.783. A total of 84 QTLs associated with soybean lodging and related traits were identified using the GB population. The contribution of phenotypic variance ranged from 1.26 to 66.87%, with LOD scores ranging from 2.52 to 69.22. Additionally, within these QTLs, a stable major QTL associated with lodging was newly discovered in the GB population. Out of the ten major QTLs associated with other related traits, nine of them were situated within the qLD-4-1 interval of the major lodging score locus, displaying phenotypic variations ranging from 12.10 to 66.87%. Specific alterations in gene expression were revealed through the analysis of resequencing data from the two parental lines, potentially indicating their significant roles in lodging. Subsequently, it was determined through qRT-PCR that four genes are likely to be the major genes controlling soybean lodging.ConclusionsThis study’s findings offer valuable insights into the genetic underpinnings of soybean lodging resistance traits. By comprehending the potential genetic factors associated with lodging, this research lays the groundwork for breeding high-yield soybeans with improved lodging resistance.

Identification of quantitative trait loci and candidate genes for pod shatter resistance in Brassica carinata

BackgroundUnderstanding the genetic control of pod shatter resistance and its association with pod length is crucial for breeding improved pod shatter resistance and reducing pre-harvest yield losses due to extensive shattering in cultivars of Brassica species. In this study, we evaluated a doubled haploid (DH) mapping population derived from an F1 cross between two Brassica carinata parental lines Y-BcDH64 and W-BcDH76 (YWDH), originating from Ethiopia and determined genetic bases of variation in pod length and pod shatter resistance, measured as rupture energy. The YWDH population, its parental lines and 11 controls were grown across three years for genetic analysis.ResultsBy using three quantitative trait loci (QTL) analytic approaches, we identified nine genomic regions on B02, B03, B04, B06, B07 and C01 chromosomes for rupture energy that were repeatedly detected across three growing environments. One of the QTL on chromosome B07, flanked with DArTseq markers 100,046,735 and 100,022,658, accounted for up to 27.6% of genetic variance in rupture energy. We observed no relationship between pod length and rupture energy, suggesting that pod length does not contribute to variation in pod shatter resistance. Comparative mapping identified six candidate genes; SHP1 on B6, FUL and MAN on chromosomes B07, IND and NST2 on B08, and MAN7 on C07 that mapped within 0.2 Mb from the QTL for rupture energy.ConclusionThe results suggest that favourable alleles of stable QTL on B06, B07, B08 and C01 for pod shatter resistance can be incorporated into the shatter-prone B. carinata and its related species to improve final seed yield at harvest.

Mitonuclear effects on sex ratio persist across generations in interpopulation hybrids.

Eukaryotic energy production requires tight coordination between nuclear and mitochondrial gene products. Because males and females often have different energetic strategies, optimal mitonuclear coordination may be sex-specific. Previous work found evidence for sex-specific mitonuclear effects in the copepod Tigriopus californicus by comparing two parental lines and their reciprocal F1 crosses. However, an alternative hypothesis is that the patterns were driven by the parental source of nuclear alleles. Here we test this alternative hypothesis by extending the same cross to F2 hybrids, who receive both maternal and paternal nuclear alleles from F1 hybrids. Results confirm mitonuclear effects on sex ratio, with distorted ratios persisting from the F1 to F2 generations, despite reduced fitness in F2 hybrids. No sex by cross interactions were found for other phenotypic traits measured. Mitochondrial DNA content was higher in females. Both routine metabolic rate and oxidative DNA damage were lower in F2 hybrids than in parentals. The persistence of sex-specific mitonuclear effects, even in the face of F2 hybrid breakdown, attests to the magnitude of these effects, which contribute to the maintenance of within-population mitochondrial DNA polymorphisms.

QTL mapping and omics analysis to identify genes controlling kernel dehydration in maize.

This study mapped and screened three candidate genes related to kernel dehydration in maize. The slow development rate of maize kernels during later stages leads to high kernel moisture content at harvest, posing a challenge for mechanized maize harvesting in China. This study utilized a recombinant inbred line population derived from Zheng 58 (slow dehydration) and PH6WC (fast dehydration) as parents. After four years of trait investigation and analysis, 25 quantitative trait loci (QTLs) associated with kernel dehydration rate and moisture content were identified, with six QTLs showing a significant contribution value exceeding 10% in the phenotype. Furthermore, a comparison was made between the QTLs identified in this study and those from previous research on maize kernel moisture content and dehydration rate, followed by screening through the omics analysis of the parental lines. Three candidate genes related to kernel dehydration rate were identified, primarily involving carbohydrate metabolism, energy metabolism processes (Zm00001d014030 and Zm00001d006476), and stimulus resistance (Zm00001d040113). These findings provide valuable insights to assist and guide future breeding efforts for mechanical harvesting of maize.

Exploring Genetic Diversity for High CBD Content in Cannabis Accessions in Tropical and Subtropical Regions of India.

Cannabis, also known as marijuana or hemp, has been utilized since ancient times for industrial, religious, recreational, and medical uses.However, regardless of the intended use, there are legal requirements for quantitative testing of cannabinoids across the supply chains. This investigation aimed to evaluate the genetic diversity of 54 Cannabis samples collected from tropical and subtropical regions in India. The research found a high genotypiccoefficient of variation(GCV), phenotypiccoefficient of variation(PCV), heritability, and genetic advance for total cannabidiol (CBD) content. The genotypic and phenotypic correlation among the morpho-chemical characters revealed strong positive correlations among most characters. Clustering and Principal component analysis identified three accessions in cluster II (CIM-CS-65, CIM-CS-189 & CIM-CS-64) with high CBD content that could be used for breeding and as sources of high CBD content in Cannabis. CIM-CS-64, with its high CBD content with 0.01%THC content, holds potential as a valuable parental line for utilization in hybridization programs and recombinant breeding. Furthermore, in accordance with the NDPC Act of 1985, CIM-CS-64 can be commercialized for medicinal purposes, making it a promising source for the development of medicinal CBD products.

SlJMJ14, identified via QTL‑seq and fine mapping, controls flowering time in tomatoes.

A major QTL, qLF2.1, for flowering time in tomatoes, was fine mapped to chromosome 2 within a 51.37-kb interval, and the SlJMJ14 gene was verified as the causal gene by knockout. Tomato flowering time is an important agronomic trait that affects yield, fruit quality, and environmental adaptation. In this study, the high-generation inbred line 19108 with a late-flowering phenotype was selected for the mapping of the gene that causes late flowering. In the F2 population derived from 19108 (late flowering) × MM (early flowering), we identified a major late-flowering time quantitative trait locus (QTL) using QTL-seq, designated qLF2.1. This QTL was fine mapped to a 51.37-kb genomic interval using recombinant analysis. Through functional analysis of homologous genes, Solyc02g082400 (SlJMJ14), encoding a histone demethylase, was determined to be the most promising candidate gene. Knocking out SlJMJ14 in MM resulted in a flowering time approximately 5-6days later than that in the wild-type plants. These results suggest that mutational SlJMJ14 is the major QTL for the late-flowering phenotype of the 19108 parental line.

Endogenous viral elements are targeted by RNA silencing pathways in banana.

Endogenous banana streak virus (eBSV) integrants derived from three distinct species, present in Musa balbisiana (B) but not Musa acuminata (A) banana genomes are able to reconstitute functional episomal viruses causing banana streak disease in interspecific triploid AAB banana hybrids but not in the diploid (BB) parent line, which harbours identical eBSV loci. Here, we investigated the regulation of these eBSV. In-depth characterization of siRNAs, transcripts and methylation derived from eBSV using Illumina and bisulfite sequencing were carried out on eBSV-free Musa acuminata AAA plants and BB or AAB banana plants with eBSV. eBSV loci produce low-abundance transcripts covering most of the viral sequence and generate predominantly 24-nt siRNAs. siRNA accumulation is restricted to duplicated and inverted viral sequences present in eBSV. Both siRNA-accumulating and nonaccumulating sequences of eBSV in BB plants are heavily methylated in all three CG, CHG and CHH contexts. Our data suggest that eBSVs are controlled at the epigenetic level in BB diploids. This regulation not only prevents their awakening and systemic infection of the plant but is also probably involved in the inherent resistance of the BB plants to mealybug-transmitted viral infection. These findings are thus of relevance to other plant resources hosting integrated viruses.

Advancements in breeding for high oil content in maize (Zea mays. L)

Maize is one of the world’s most important food crops, supplying&gt;5% deity energy. Due to its wider adaptability, high yield potential, maize is widely utilized as food and animals world worldwide. It enriched with caloric starch and the high energy in its oil. The kernel oil content in commercial high-oil maize hybrids averages ∼8%, far lower than that in developed high-oil maize lines (as high as 20%). The maize seed/kernel consisted of endosperm (82%) and the germ (embryo and scutellum) (12%). The germ region makes up 80–84% of kernel oil, with the aleurone and endosperm making up 12% and 5%, respectively. High-oil maize may serve as a valuable forage maize germplasm for breeding. Maize oil is also considered as high-quality oil for human health due to the high proportion of polyun-saturated fatty acids. Selection for high oil increases the proportion of germ and further content of germ oil. The problems that over-shadow the successful production of high-oil corn are low grain yield potential, physiological cost of oil synthesis, low seed vigor, low kernel weight, shorter seed longevity, and poor germination of high-oil corn lines. It is necessary to make efforts to generate nested populations or use marker-assisted recurrent selection (MARS) to accumulate the advantageous quantitative trait loci (QTLs) in the pa-rental lines. The oil content of maize inbreeds and hybrids could be further improved with the use of transgenes, genomics, and metabolic engineering technologies in new insight for the development of high oil maize breeding and strategies.

Estimation of Heterosis and Combining Ability for Quality Traits in Bottle Gourd [Lagenaria siceraria (Mol.) Standl.

An experiment was conducted at the Vegetable Research Farm, Maharajpur, Department of Horticulture, JNKVV, Jabalpur in kharif season of 2022 and 2023. The current study evaluated the performance of 23 bottle gourd genotypes, including 6 parental lines, their 15 diallel crosses, and 2 checks, focusing on their quality traits. Over two years of pooled data, genotype, JBG-4×JBG-5 was found to possess maximum TSS (3.93 °Brix), followed by JBG-2×JBG-4 (3.77 °Brix). JBG-4×JBG-5 was found to have maximum ascorbic acid content (14.48 mg 100-1 g) followed by JBG-4 (14.01 mg 100-1 g). Rind thickness was found maximum in JBG-2×JBG-4 (3.36 mm) followed by JBG-2×JBG-3 (3.28 mam). This study found a substantial association between the total soluble solids (TSS) and ascorbic acid content with the yield of bottle gourd genotypes. Among the genotypes, JBG-4×JBG-5 demonstrated the highest yield per plant, along with the highest total soluble solids (TSS) and ascorbic acid content. Regarding heterosis, JBG-4×JBG-5 has found the highest heterosis for total soluble solids and ascorbic acid content. JBG-4 and JBG-2 are the best general combiners for TSS, ascorbic acid content, and rind thickness. JBG-4×JBG-5 has found the best specific combiner for TSS and ascorbic acid content.

Extracellular vesicles from highly invasive melanoma subpopulations increase the invasive capacity of less invasive melanoma cells through mir-1246-mediated inhibition of CCNG2

Invasive growth is a critical process in tumor progression, requiring the activation of various molecular processes in tumor cells at the invasive front. Intercellular communication between heterogeneous tumor cells enhances cellular activation and adaptation to specific microenvironments. One mechanism of intercellular communication is the delivery of miRNAs through tumor cell-derived extracellular vesicles (EVs). In this context we have observed that conditioned media from a highly invasive cell subpopulation (BLM-HI) enhances the invasive capacity of the parental cell line (BLM). Therefore, we hypothesized that this complex change of cellular behavior is influenced by EV-transported miRNAs. The treatment of BLM cells with EVs derived from BLM-HI cells resulted in a significantly enhanced invasive capacity, as observed in Matrigel-embedded spheroids and in 2D Boyden chamber assays, with a dose-dependent effect. Conversely, the invasive capacity of BLM cells was reduced when secretion of EVs was inhibited by a sphingomyelinase inhibitor. To investigate the molecular mechanisms behind this effect, we performed next-generation sequencing and identified an enrichment of miR-1246 in these EVs. In functional analyses we demonstrated that both the EV mediated delivery of miR-1246 as well as overexpression contributes to the enhanced invasiveness of BLM cells. We identified a binding site of miR-1246 in the 3’UTR of cyclin G2 (CCNG2) and demonstrated direct binding by a luciferase reporter assay.Increased expression of CCNG2 has been associated with cancer metastasis and poor patient outcomes in other malignancies. Our study demonstrates that intercellular communication contributes to the transfer of properties, such as increased invasive capacity, between heterogeneous melanoma cells via EV-transported miRNAs.