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Simple Summary: Humans are diploid organisms, carrying one set of chromosomes from our mother and one from our father. Plants can exist as diploid or polyploid, carrying multiple chromosome copies. Plant breeders can cross polyploid crops in unique and beneficial ways that are not possible in diploid crops. It will be necessary to produce food in a more sustainable manner, with less virgin land turned over and fewer resources consumed, therefore the study of hybrid polyploid crops is essential for the improvement of our food system. The improvement in quantitative traits (e.g., yield, size) in F1 offspring over parent lines is described as hybrid vigour, or heterosis. There exists a fascinating relationship between parental genetic distance and genome dosage (polyploidy), and heterosis effects. The contribution of nuclear heterozygosity to heterosis is not uniform across diploid and polyploid crops, even within same species, thus demonstrating that polyploid crops should be part of any discussion on the mechanisms of heterosis. This review examines the records of correlating heterosis with parental genetic distance and the influence of adding supplementary genomes in wide crosses. Increasing nuclear heterozygosity through parental genetic distance has been shown to be an imperfect predictor for heterosis in a variety of commercial crops such as maize, rice, and pepper. However, increasing the ploidy level raises the maximum number of alleles that can be harboured at any one locus, and studies on crops such as oilseed rape, potato, alfalfa, maize, and rice have demonstrated that heterosis may be maximised upon increasing multi-locus nuclear heterozygosity. The novel heterotic phenotypes observed above the diploid level will contribute to our understanding on the mechanisms of heterosis and aid plant breeders in achieving the righteous goal of producing more food with fewer inputs. [ABSTRACT FROM AUTHOR]

Parental selection is important for heterosis formation during crossbreeding of Populus. However, in poplar hybrids, the effect of parents on vegetative growth heterosis is not well understood. In this study, one female parent (P. simonii XY4) and two male parents (P. nigra OH and P. deltoides × P. nigra BJLY3#) were used to produce two progenies (Hyb1 and Hyb2). Vegetative growth investigation showed that both Hyb1 and Hyb2 performed heterosis in plant growth and ground diameter. The vegetative growth of hybrids was strongly correlated with the male parents but not with the female parents. The gene expression levels in the hybrids were more biased toward the male parents. In Hyb1 and Hyb2, 51.93% and 45.03% of the expressed genes showed the non-additive effect, respectively, and over 65% of the non-additively expressed genes showed the dominant effect. It is noteworthy that genes of paternal expression dominant effect (ELD_♂) account for the majority of dominantly expressed genes, suggesting the paternal contribution to heterosis. KEGG enrichment analysis indicated that a large number of non-additively expressed genes were enriched in the plant hormone signal transduction pathway. WGCNA analysis showed that MEcyan was significantly correlated with the traits of hybrids, and 12 plant hormone signal transduction pathway genes were enriched in this module. Transcription factors (TFs) MYB88, LHY, and TCP4 may be involved in the regulation of these pathway genes. This finding supported that the male parents play an important role in the formation of vegetative growth heterosis of Populus. In addition, the non-additively expressed genes of the signal transduction pathway and the regulation of TFs related to these pathway genes may be one of the reasons for the generation of heterosis. [ABSTRACT FROM AUTHOR]

Glioma is an aggressive malignant brain tumor with a very poor prognosis for survival. The poor tumor targeting efficiency and tumor microenvironment penetration barrier also as troubles inhibited the effective glioma chemotherapy. Here, we design a core-shell structure cascade amplified hybrid catalytic nanopotentiators CFpAD with DM1 encapsulated to overcome the glioma therapeutic obstacles. NIR laser-based BBB penetrating enhances the tumor accumulation of CFpAD. When CFpAD, as the cascade amplified drug, is treated on the cancer cells, the bomb-like CFpAD releases gold nanoparticles as glucose oxidase (GOx) and ferric oxide nanoparticles (FNPs) as peroxides (POx) after blasting, producing ROS via a cascade amplification for tumor cell apoptosis. Gold nanoparticles can rest CAFs and reduce ECM secretion, achieving deep penetration of CFpAD. Moreover, CFpAD also cuts off the nutritional supply of the tumor, reduces the pH value, and releases free radicals to destroy the cancer. The glioma cell viability was significantly decreased through DNA damage and ROS aggregation due to the DM1-based chemotherapy synergistically combined with interventional photothermal therapy (IPTT) and radiotherapy (RT). This domino cascade amplified loop, combined with starvation therapy with IPTT and RT, has good tumor penetration and outstanding antitumor efficacy, and is a promising glioma treatment system. Schematic illustration of a combined interventional therapy strategy for enhancing glioma penetration and CFpAD anti-tumor efficacy through cascade amplification. (A) Preparation of FNCp, FpA, and CFpAD. (B) The blood-brain barrier is temporarily opened with IPTT. (C) Hybrid nanopotentiators reduce interstitial fluid pressure through CAF quiescence and increase the permeability of therapeutic agents. (D) Hybrid nanopotentiators consume glucose to reduce tumor pH, produce oxygen to improve tumor hypoxia, and generate ROS to inhibit tumor proliferation. [Display omitted] • Dual cascade amplified hybrid nanopotentiators are designed for glioma. • Hybrid nanopotentiators can not only enhance the deep penetration of nanoparticle, but also enhance its catalytic ability. • Nanopotentiators have effective antitumor activity. [ABSTRACT FROM AUTHOR]

The article presents a study which investigated the genetic factors influencing yield in eggplant (Solanum melongena L) hybrids under organic cultivation conditions in India. Topics include genetic and phenotypic variations of India's primary origin for eggplant, effects of genotypes on yield and other characters in eggplant, and estimation of heterosis over the better parent and heck variety (PPL) for yield and other different characters in eggplant.

The article presents a study which estimated combining ability and heterosis of pearl millet hybrids for yield, and other yield components and identified superior pearl millet hybrids. Topics include analysis of variance for combining ability and estimation of variance components for grain yield and its components, estimates of general combining ability (GCA) of parents and specialized combining ability (SCA) effects of crosses, and estimates of SCA effects for eight characters in pearl millet.

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The present experiment was conducted in bhindi / okra to observe the extent of heterosis for eight characters of plant and fruit yield traits through diallel analysis. The characters consist of plant height (cm), number of primary branches per plant, node at which 1st flower appears, number of nodes on main stem, internodal length, days to 50% flowering, pod yield per plant (g) and pod yield per hectare (q/ha). The experimental material comprised of 66 F1 hybrids developed from crossing 12 okra genotypes in diallel crossing excluding reciprocals. Out of eight characters studied, plant height, number of branches per plant and number of nodes on main stem are growth determining features. They generally decide the fruit/pod bearing surface of the okra plant. Therefore, Positive heterosis is desirable for plant height, number of branches per plant, number of nodes on main stem including fruit yield per plant and fruit yield per hectare but negative heterosis is profitable for node at which 1st flower appears, intermodal length and days to 50% flowering. Out of 66 F1, 50, 32 and 38 hybrids showed significant heterosis positively over mid parent, better parent and standard check respectively for fruit yield per plant and fruit yield per hectare and the highest was reported in hybrids IC-45831 ×IC-43733 subsequently IC-45831 ×Pusa A-4. [ABSTRACT FROM AUTHOR]

Hybrid genotypes can provide significant yield gains over conventional inbred varieties due to heterosis or hybrid vigor. However, hybrids can also display unintended negative attributes or phenotypes such as extreme pathogen susceptibility. The necrotrophic pathogen Pyrenophora teres f. maculata (Ptm) causes spot form net blotch, which has caused significant yield losses to barley worldwide. Here, we report on a non-transgressive hybrid susceptibility locus in barley identified between the three parental lines CI5791, Tifang and Golden Promise that are resistant to Ptm isolate 13IM.3. However, F2 progeny from CI5791 × Tifang and CI5791 × Golden Promise crosses exhibited extreme susceptibility. The susceptible phenotype segregated in a ratio of 1 resistant:1 susceptible representing a genetic segregation ratio of 1 parental (res):2 heterozygous (sus):1 parental (res) suggesting a single hybrid susceptibility locus. Genetic mapping using a total of 715 CI5791 × Tifang F2 individuals (1430 recombinant gametes) and 149 targeted SNPs delimited the hybrid susceptibility locus designated Susceptibility to Pyrenophora teres 2 (Spt2) to an ~ 198 kb region on chromosome 5H of the Morex V3 reference assembly. This single locus was independently mapped with 83 CI5791 × Golden Promise F2 individuals (166 recombinant gametes) and 180 genome wide SNPs that colocalized to the same Spt2 locus. The CI5791 genome was sequenced using PacBio Continuous Long Read technology and comparative analysis between CI5791 and the publicly available Golden Promise genome assembly determined that the delimited region contained a single high confidence Spt2 candidate gene predicted to encode a pentatricopeptide repeat-containing protein. [ABSTRACT FROM AUTHOR]

Some of the most impactful invasive plants are hybrids that exhibit heterosis and outperform their parent species. Heterosis can result from multiple genetic processes, and may also be more likely when parental populations are inbred. However, although outcrossing between relatives and self-fertilization both occur in many widespread plants, no study to our knowledge has investigated whether inbreeding in parental populations could help to explain heterosis in hybrid plants that have displaced their parent species. In the wetlands of southeastern Canada there is a widespread Typha (cattail) hybrid zone in which native T. latifolia (broad-leafed cattail) interbreeds with introduced T. angustifolia (narrow-leafed cattail) to produce the invasive hybrid T. × glauca. Typha reproduce through self-fertilization, outcrossing, and clonal propagation. Heterosis has been identified in T. × glauca by comparing proxy fitness measures between hybrids and parent species, but these studies did not consider the potential importance of inbreeding in parental populations. Because F1 hybrids have higher heterozygosity than their parent species, the self-fertilized offspring of hybrids should have higher heterozygosity than the self-fertilized offspring of parent species; the latter should therefore be more inbred, and potentially more susceptible to inbreeding depression (ID). We tested the hypothesis that self-fertilization leads to greater ID in the offspring of T. latifolia and T. angustifolia compared to the offspring of F1 T. × glauca. We conducted common-garden and wetland experiments using seeds from hand-pollinated plants sourced from natural populations, and quantified several fitness-related metrics in the offspring of self-fertilized versus outcrossed parent species and hybrids. Our experiments provided no evidence that inbreeding leads to ID in self-fertilized T. angustifolia, T. latifolia or T. × glauca in either a common garden or a natural wetland, and thus show that heterosis in a widespread invasive hybrid does not rely on comparisons with inbred parents. [ABSTRACT FROM AUTHOR]

Estimates of combining ability help determine the value of hull-less pumpkin (Cucurbita pepo L. var. styriaca) lines in producing new hybrids with high yield and better quality. This research was conducted to estimate the general and specific combining abilities and heterosis in six inbred lines proposed for hull-less pumpkins at the University of Guilan. Analysis of variance indicated that responses for all traits differed significantly. The highest fruit yield and seed length were related to the hybrid 14x16, the highest number of seeds was related to the hybrid 16x23, the highest percentage of oil was related to the hybrid 11x14 and the highest yield of oil was related to 11x23. Considering the high value of combining ability and the heterosis compared to the average of the parent and high parent, it is possible to increase the oil yield and the seed yield by using the 11x23 hybrid. The 16x23 hybrid proposes to increase the number of seeds. The best specific combining ability (SCA) for seed number was associated with the 16x23. The 11x14 had the best SCA for the oil yield per hectare. The 11x 23 had the best SCA for the seed yield per hectare. Significant specific combining ability and high heterosis for traits indicated low additive and high dominant gene action on hull-less pumpkin traits, therefore crossing between lines to release new hybrid cultivars is necessary for Iran's pumpkin breeding program. [ABSTRACT FROM AUTHOR]

Aims: The genic male sterility (GMS) system is an important strategy for generating heterosis in plants. To better understand the essential role of lipid and sugar metabolism and to identify additional candidates for pollen development and male sterility, transcriptome and metabolome analysis of a GMS line of 1205AB in B. napus was used as a case study. Data resources generated: To characterize the GMS system, the transcriptome and metabolome profiles were generated for 24 samples and 48 samples of 1205AB in B. napus, respectively. Transcriptome analysis yielded a total of 156.52 Gb of clean data and revealed the expression levels of 109,541 genes and 8,501 novel genes. In addition, a total of 1,353 metabolites were detected in the metabolomic analysis, including 784 in positive ion mode and 569 in negative ion mode. Key results: A total of 15,635 differentially expressed genes (DEGs) and 83 differential metabolites (DMs) were identified from different comparison groups, most of which were involved in lipid and sugar metabolism. The combination of transcriptome and metabolome analysis revealed 49 orthologous GMS genes related to lipid metabolism and 46 orthologous GMS genes related to sugar metabolism, as well as 45 novel genes. Utility of the resource: The transcriptome and metabolome profiles and their analysis provide useful reference data for the future discovery of additional GMS genes and the development of more robust male sterility breeding systems for use in the production of plant hybrids. [ABSTRACT FROM AUTHOR]

The hybrid between the female channel catfish (Ictalurus punctatus) and the male blue catfish (I. furcatus) is the best genetic type currently available for commercial catfish farming due to their superior traits. However, further genetic improvements can be achieved by selecting parents with increased combining abilities. Twenty female channel catfish and twelve male blue catfish were crossed in a partial factorial mating design, resulting in forty hybrid families. These families were evaluated for early growth in three different rearing systems, including ponds and aquaria. The early growth performance of hybrid catfish was significantly (p < 0.05) affected by the additive gene action of the female parent and the male parent. There were genotype–environment or genotype–age interactions affecting the combining abilities, both the amount and the type of genetic variation. Dam GCA was significant in all environments/ages; however, sire GCA was variable, and SCA was not significant. These findings suggest that reciprocal recurrent selection for growth could potentially improve the performance of F1 hybrid catfish. [ABSTRACT FROM AUTHOR]

This article discusses the importance of heterosis in wheat breeding and presents the findings of a study on wheat genetics and plant breeding. The study identified promising cross combinations that exhibited significant levels of desirable heterosis for various traits, including plant height, productive tillers per plant, spike length, flag leaf area, grains per spike, 1000-grain weight, biological yield per plant, harvest index, and grain yield per plant. The results suggest that these heterotic crosses can be utilized to develop high-yielding wheat varieties and improve overall crop performance. The study also highlights the potential for incorporating marker-assisted breeding techniques in future research. [Extracted from the article]

Corn germplasm with different mesocotyl elongation was characterized for High Valleys in Mexico by estimating the general combinatory aptitude (GCA), specific combinatory aptitude (SCA), heterosis (H), inbreeding depression (ID) and principal component aptitude (PCA), with the purpose of directing the improvement for deep sowing. The hypothesis was that the parents and crosses of mesocotyl present variability in seedling and adult plant traits based on deep sowing. The 36 F1 and F2 crosses—derived from nine parents, three with short mesocotyl (S), three medium (M) and three long (L), obtained through Griffing diallel II—plus the parents were planted in sand beds and polyethylene bags in a greenhouse during the spring–summer cycles of 2021 and 2022. The following traits were measured: length of mesocotyl (LM), length of coleoptile, total seedling dry matter and 10 cob traits in addition to total dry matter. In 11 of the 14 traits, there was a positive and significant correlation (p ≤ 0.05) between the GCA of the parents and their LM. The highest SCA, H and ID (p ≤ 0.05) were for crosses L × L for all the traits measured. When comparing the GCA/SCA proportions, this relation varied from 0.76 to 0.97, which points to practically equal additive effects with those of dominance; however, in parents and L × L crosses, this relation was on average 0.94, 1.07 in M × M, 0.22 in S × S and 0.36 in L × S. In both F1 and F2, the variation was explained by two principal components: 89.5% for GCA and 73.4% for SCA. In both generations, the parents with higher GCA were H-48, HS-2 and Promesa, the three with long mesocotyl, while those with the highest GCA were crosses between these three hybrids. [ABSTRACT FROM AUTHOR]

Simple Summary: Hybrid rice is produced by crossing a male sterile rice line (the A line) with a pollen doner that restores fertility (the restorer line). The consequential outbreeding can result in plant growth and yields that are above the average of the parental lines (a condition called heterosis). This gives rise to a normally higher productivity of hybrids compared to pure-line (inbred) rice varieties. However, hybrid rice has also been associated with higher herbivore damage compared to inbreds. In particular, susceptibility to the whitebacked planthopper (Sogatella furcifera) has been linked to the A line in early generation hybrids. We tested whether hybrids had heterosis for resistance to the whitebacked planthopper, brown planthopper (Nilaparvata lugens) and yellow stemborer (Scirpophaga incertulas) in a series of greenhouse and field experiments. In the field plots, heterosis resulted in relatively high hybrid yields. There were few cases of heterosis for resistance to herbivores in the greenhouse or field and only one of eight A lines was associated with susceptibility to planthoppers. Susceptibility to the yellow stemborer was largely due to plant physiology: larger, fast-growing and late-maturing varieties, including hybrids, were more vulnerable to stemborers. Therefore, susceptibility to stemborers was often a consequence of heterosis for plant biomass. We make a series of recommendations to improve screening and breeding for resistance to herbivores in hybrid rice. Three-line hybrid rice is produced by crossing male sterile (A line) rice with a fertility-restorer (R line). Fertile lines (B lines) are also required to maintain A line seed for breeding programs. We used a range of hybrids and their parental lines to assess the frequency and nature of heterosis for resistance to the whitebacked planthopper (Sogatella furcifera), brown planthopper (Nilaparvata lugens) and yellow stemborer (Scirpophaga incertulas). Heterosis is defined as trait improvement above the average of the parental lines as a result of outbreeding. Based on the results from a greenhouse study that challenged hybrids and their parental lines with each herbivore species, we found that susceptibility to planthoppers was associated with one of the eight A lines tested, but resistance was improved by crossing with a relatively resistant restorer. Higher frequencies of heterosis for susceptibility in comparisons between hybrids and their B lines suggest that susceptibility was not related to the cytoplasmic genomes of the associated sterile A lines. Furthermore, because none of the parental lines possessed currently effective resistance genes, improved resistance against planthoppers was probably due to quantitative resistance. In a related field trial, hybrids had generally higher yields than their fertile parents and often produced larger grain; however, they were often more susceptible to stemborers, leaffolders (Cnaphalocrocis medinalis) and other caterpillars (Rivula atimeta). This was largely a consequence of hybrid heterosis for plant biomass and was strongly affected by crop duration. We make a series of recommendations to improve hybrid breeding to reduce the risks of herbivore damage. [ABSTRACT FROM AUTHOR]

This document is a corrigendum for an article titled "Combining modeling with novel field observations yields new insights into wintertime food limitation of larval fish" published in the journal Limnology & Oceanography. The corrigendum addresses two errors in the original publication. Firstly, the correct unit of larval length is mm, not cm. Secondly, Equation 2 in the article was partially wrong and is replaced with the correct equation. The authors apologize for the errors and assure readers that the corrections do not affect any of the figures, results, discussions, or conclusions of the article. [Extracted from the article]

Virtually all aspects of the biology of ectotherms are size‐and temperature‐dependent. Aerobic metabolism is often proposed to explain such relationships, with oxygen limitation setting limits to heat tolerance and constraining growth. However, experimental tests of the role of oxygen in heat tolerance have yielded mixed results, suggesting that oxygen limitation may be important only in certain contexts and on certain time scales but not others.Here, using thermal death time curves, which incorporate the intensity and duration of heat stress, we quantify the ability to survive heat stress in multiple inbred lines of Drosophila melanogaster, under normal and low oxygen conditions. The lines were selected to differ markedly in body size and cell size, as these traits have been hypothesised to shape thermal tolerance via their effects on oxygen supply and demand.Low oxygen condition markedly reduced survival time across inbred lines, especially when flies were exposed to prolonged, mild heat stress.Variations in heat tolerance among lines were partly related to cell size and body size differences, especially under chronic exposure to high temperatures, under hypoxia and in flies that exhibit larger cell size, supporting the idea that differences in cell size affect the oxygen supply and demand via differences in surface area to volume ratio.Because differences in heat tolerance were manifested at different timescales, our results underscore the need to close the gap between responses to acute timescales, typically employed in laboratory studies, and chronic timescales, which are ecologically more relevant. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

In sorghum [Sorghum bicolor (L.) Moench], combining ability and heterosis analysis are commonly used to evaluate superior parental lines and to screen for strongly heterotic hybrids, which helps in sorghum variety selection and breeding. In this context, combining ability and heterosis analysis were assessed using 14 restorer lines and seven cytoplasmic male sterile (CMS) lines in 2019 and 2020. The analysis of variance of all cross combinations had highly significant differences for all characters studied, which indicated a wide variation across the parents, lines, testers, and crosses. Combining ability analysis showed that the general combining ability (GCA) and specific combining ability (SCA) of the different parents were differed significantly among different traits. Most combinations with high SCA also showed high GCA in their parent lines. The heritability in the narrow sense of grain weight per panicle and grain yield was relatively low, indicating that the ability of these traits to be directly inherited by offspring was weak, that they were greatly affected by the environment. The better-parent heterosis for plant height, grain weight per panicle, panicle length, and 1000-grain weight was consistent with the order of mid-parent heterosis from strong to weak. The GCA effects of two lines 10480A, 3765A and three testers 0-30R, R111, and JY15R were significant for the majority of the agronomic traits including grain yield and might be used for improving the yield of grains in sorghum as parents of excellent specific combining ability. Seven strongly heterotic F1 hybrids were screened; of these, hybrids 3765A × R111, 1102A × L2R, and 3765A × JY15R showed significant increases in seed iristectorigenin A content and will feature into the creation of new sorghum varieties rich in iristectorigenin A. [ABSTRACT FROM AUTHOR]

This document provides a comprehensive overview of the use of male sterility in vegetable crops for hybrid breeding. It explains the different types of male sterility, such as cytoplasmic male sterility (CMS) and cytoplasmic-genic male sterility (CGMS), and their applications in crops like onion, carrot, chilli, and cabbage. The document also discusses the use of chemically induced male sterility as an alternative method. It emphasizes the importance of developing resistant hybrids and using molecular markers in vegetable crop production. The document is a compilation of research articles and reviews that cover a range of plant species and provide valuable information for researchers and breeders interested in developing hybrid varieties of these crops. [Extracted from the article]

This article presents the findings of a study on the breeding of Indian Mustard, specifically focusing on heterosis and combining ability for seed yield and its component traits. The researchers evaluated 12 advanced lines/varieties of Indian Mustard and found significant differences among the treatments for various traits. Certain lines and cross combinations were identified as good combiners and showed high heterosis. The study provides valuable information for breeding programs aimed at improving seed yield and its component traits in Indian Mustard. [Extracted from the article]

The success of hybrid breeding programs across the world depends on an understanding of the impacts of gene activity, combining ability, and heterosis on desired characteristics. This project's major goals included the identification of better-inbred lines and hybrids based on combining prowess and heterosis effects in genotypes of super-sweet maize (Zea mays L. Saccharate) and the research of genetic factors and gene activity influencing agronomic attributes. In 2021, three inbred lines (as female parents) were crossed with three testers (as male parents) using the line-to-tester mating design. In a Randomized Complete Block Design (RCBD) with three replications in 2022, nine F1 hybrids with six parental lines were assessed for thirteen agronomic variables, including tillering potential (TP), conservable grain yield (CGY), and yield components. The findings showed that for all the attributes under study, the genotyperelated mean squares and their distributions to parents crosses, and parents' crosses were significant (P 0.05). Numerous agronomic characteristics, including TP, CGY, plant height, and tassel length, were considerably influenced by additive gene action, while others were influenced by non-additive gene action, according to the ratio of 2GCA / 2SCA and narrow-sense heritability (Hns2). For CGY and TP characteristics, the SSBas-1 and SSChall-5 combination showed positive specific combining ability (SCA) benefits. Most hybrids also showed positive heterosis and SCA effects, which explained the heterosis in the hybrid's performance. The best general combiners for the majority of the analyzed traits were the parents SBas-1 among the lines and Chal-3 among the testers, which might be employed in further research to create high-yielding super-sweet corn hybrids. [ABSTRACT FROM AUTHOR]

Metformin (Met) is the first-line therapy in type 2 diabetes mellitus but, in last few years, it has also been evaluated as anti-cancer agent. Several pathways, such as AMPK or PI3K/Akt/mTOR, are likely to be involved in the anti-cancer Met activity. In addition, hydrogen sulfide (H2S) and H2S donors have been described as anti-cancer agents affecting cell-cycle and inducing apoptosis. Among H2S donors, isothiocyanates are endowed with a further anti-cancer mechanism: the inhibition of the histone deacetylase enzymes. On this basis, a hybrid molecule (Met-ITC) obtained through the addition of an isothiocyanate moiety to the Met molecule was designed and its ability to release Met has been demonstrated. Met-ITC exhibited more efficacy and potency than Met in inhibiting cancer cells (AsPC-1, MIA PaCa-2, MCF-7) viability and it was less effective on non-tumorigenic cells (MCF 10-A). The ability of Met-ITC to release H2S has been recorded both in cell-free and in cancer cells assays. Finally, its ability to affect the cell cycle and to induce both early and late apoptosis has been demonstrated on the most sensitive cell line (MCF-7). These results confirmed that Met-ITC is a new hybrid molecule endowed with potential anti-cancer properties derived both from Met and H2S. [ABSTRACT FROM AUTHOR]

Background: Trisomy 18 syndrome, also known as Edwards syndrome, is a chromosomal trisomy. The syndrome has historically been considered lethal owing to its poor prognosis, and palliative care was primarily indicated for trisomy 18 neonates. Although there have been several reports on the improvement of survival outcomes in infants with trisomy 18 syndrome through neonatal intensive care, few studies have compared the impact of neonatal intensive care on survival outcomes with that of non-intensive care. Therefore, we compared the survival-related outcomes of neonates with trisomy 18 between intensive and non-intensive care. Methods: Seventeen infants of trisomy 18 admitted to our center between 2007 and 2019 were retrospectively studied. We divided the patients into a non-intensive group (n = 5) and an intensive group (n = 12) and evaluated their perinatal background and survival-related outcomes of the two groups. Results: The 1- and 3-year survival rates were both 33% in the intensive group, which was significantly higher than that in the non-intensive group (p < 0.001). Half of the infants in the intensive care group were discharged alive, whereas in the non-intensive care group, all died during hospitalization (p = 0.049). Conclusions: Neonatal intensive care for neonates with 18 trisomy significantly improved not only survival rates but also survival-discharge rates. Our findings would be helpful in providing 18 trisomy neonates with standard neonatal intensive care when discussing medical care with their parents. [ABSTRACT FROM AUTHOR]

A role of ecological adaptation in speciation can be obscured by stochastic processes and differences that species accumulate after genetic isolation. One way to identify adaptive characters and their underlying genes is to study cases of speciation involving parallel adaptations. Recently resolved phylogenies reveal that alpine morphology has evolved in parallel in the genus Antirrhinum (snapdragons): first in an early split of an alpine from a lowland lineage and, more recently, from within the lowland lineage to produce closely related sympatric species with contrasting alpine and lowland forms. Here, we find that two of these later diverged sympatric species are differentiated by only around 2% of nuclear loci. Though showing evidence of recent gene flow, the species remain distinct for a suite of morphological characters typical of earlier‐diverged alpine or lowland lineages and their morphologies correlate with features of the local landscape, as expected of ecological adaptations. Morphological differences between the two species involve multiple, unlinked genes so that parental character combinations are readily broken up by recombination in hybrids. We detect little evidence for post‐pollination barriers to gene flow or recombination, suggesting that genetic isolation related to ecological adaptation is important in maintaining character combinations and might have contributed to parallel speciation. We also find evidence that genes involved in the earlier alpine‐lowland split were reused in parallel evolution of alpine species, consistent with introgressive hybridisation, and speculate that many non‐ecological barriers to gene flow might have been purged during the process. [ABSTRACT FROM AUTHOR]

Successful use of woody species in reducing climatic and environmental risks of energy shortage and spreading pollution requires deeper understanding of the physiological functions controlling biomass productivity and phytoremediation efficiency. Targets in the breeding of energy willow include the size and the functionality of the root system. For the combination of polyploidy and heterosis, we have generated triploid hybrids (THs) of energy willow by crossing autotetraploid willow plants with leading cultivars (Tordis and Inger). These novel Salix genotypes (TH3/12, TH17/17, TH21/2) have provided a unique experimental material for characterization of Mid-Parent Heterosis (MPH) in various root traits. Using a root phenotyping platform, we detected heterosis (TH3/12: MPH 43.99%; TH21/2: MPH 26.93%) in the size of the root system in soil. Triploid heterosis was also recorded in the fresh root weights, but it was less pronounced (MPH%: 9.63–19.31). In agreement with root growth characteristics in soil, the TH3/12 hybrids showed considerable heterosis (MPH: 70.08%) under in vitro conditions. Confocal microscopy-based imaging and quantitative analysis of root parenchyma cells at the division–elongation transition zone showed increased average cell diameter as a sign of cellular heterosis in plants from TH17/17 and TH21/2 triploid lines. Analysis of the hormonal background revealed that the auxin level was seven times higher than the total cytokinin contents in root tips of parental Tordis plants. In triploid hybrids, the auxin–cytokinin ratios were considerably reduced in TH3/12 and TH17/17 roots. In particular, the contents of cytokinin precursor, such as isopentenyl adenosine monophosphate, were elevated in all three triploid hybrids. Heterosis was also recorded in the amounts of active gibberellin precursor, GA19, in roots of TH3/12 plants. The presented experimental findings highlight the physiological basics of triploid heterosis in energy willow roots. [ABSTRACT FROM AUTHOR]

SUMMARY: The genetic factors underlying growth traits differ over time points or stages. However, most current studies of phenotypes at single time points do not capture all loci or explain the genetic differences underlying growth trajectories. Hybrid Liriodendron exhibits obvious heterosis and is widely cultivated, although its complex genetic mechanism underlying growth traits remains unknown. A genome‐wide association study (GWAS) is an effective method for elucidating the genetic architecture by identifying genetic loci underlying complex quantitative traits. In the present study, using a GWAS, we identified robust loci associated with growth trajectories in hybrid Liriodendron populations. We selected 233 hybrid progenies derived from 25 crosses for resequencing, and measured their tree height (H) and diameter at breast height (DBH) for 11 consecutive years; 192 972 high‐quality single nucleotide polymorphisms (SNPs) were obtained. The dynamics of the multiyear single‐trait GWAS showed that year‐specific SNPs predominated, and only five robust SNPs for DBH were identified in at least three different years. Multitrait GWAS analysis with model parameters as latent variables also revealed 62 SNPs for H and 52 for DBH associated with the growth trajectory, displaying different biomass accumulation patterns, among which four SNPs exerted pleiotropic effects. All identified SNPs also exhibited temporal variations in effect sizes and inheritance patterns potentially related to different growth and developmental stages. The haplotypes resulting from these significant SNPs might pyramid favorable loci, benefitting the selection of superior genotypes. The present study provides insights into the genetic architecture of dynamic growth traits and lays a basis for future molecular‐assisted breeding. Significance Statement: GWAS is an effective tool to elucidate the genetic architecture of complex traits. However, most studies focus on single‐time‐point phenotypes, failing to capture all loci or explain genetic differences underlying growth trajectories. Here, we conducted dynamic GWASs for growth traits over 11 years on hybrid Liriodendron, identifying robust loci affecting growth traits and trajectories. Our findings offer new insights into the genetic basis of dynamic growth traits and lay a foundation for future molecular‐assisted breeding. [ABSTRACT FROM AUTHOR]

Salinity is a widespread abiotic stress that devastatingly impacts wheat growth and restricts its productivity worldwide. The present study is aimed at elucidating biochemical, physiological, anatomical, gene expression analysis, and agronomic responses of three diverse wheat genotypes to different salinity levels. A salinity treatment of 5000 and 7000 ppm gradually reduced photosynthetic pigments, anatomical root and leaf measurements and agronomic traits of all evaluated wheat genotypes (Ismailia line, Misr 1, and Misr 3). In addition, increasing salinity levels substantially decreased all anatomical root and leaf measurements except sclerenchyma tissue upper and lower vascular bundle thickness compared with unstressed plants. However, proline content in stressed plants was stimulated by increasing salinity levels in all evaluated wheat genotypes. Moreover, Na+ ions content and antioxidant enzyme activities in stressed leaves increased the high level of salinity in all genotypes. The evaluated wheat genotypes demonstrated substantial variations in all studied characters. The Ismailia line exhibited the uppermost performance in photosynthetic pigments under both salinity levels. Additionally, the Ismailia line was superior in the activity of superoxide dismutase (SOD), catalase activity (CAT), peroxidase (POX), and polyphenol oxidase (PPO) enzymes followed by Misr 1. Moreover, the Ismailia line recorded the maximum anatomical root and leaf measurements under salinity stress, which enhanced its tolerance to salinity stress. The Ismailia line and Misr 3 presented high up-regulation of H+ATPase, NHX2 HAK, and HKT genes in the root and leaf under both salinity levels. The positive physiological, anatomical, and molecular responses of the Ismailia line under salinity stress were reflected on agronomic performance and exhibited superior values of all evaluated agronomic traits. [ABSTRACT FROM AUTHOR]

The edible oyster mushroom Pleurotus ostreatus is one of the most cultivated species worldwide. Morphogenesis associated with the maturation of fruit bodies is controlled by two unlinked loci of sexual compatibility matA and matB with multiple alleles (tetrapolar system of sexual compatibility). Quantitative analysis of the alleles of mating compatibility loci in 17 natural isolates collected in the Moscow region was performed in mon–mon (monokaryons–monokaryon) and di–mon (dikaryon–monokaryon) crossings. Four monokaryotic testers strains which were heteroallelic at both mating type loci were obtained for each of the five natural mushroom isolates by using original technique of sterile spore prints on Petri dishes and mon–mon crossing. Twelve natural isolates were crossed via di-mon mating with the four monokaryotic testers M-38. Genetic analysis of the alleles of sexual compatibility loci in 17 natural isolates revealed multiple alleles at both loci: at least ten alleles at matA locus and eight alleles at matB locus. Structural organization analysis of the matA locus was performed in silico for homokaryotic strains PC9 and PC15 based on the whole-genome sequencing data available at DOE Joint Genome Institute. The matA locus has an extremely divergent structure: there are one copy of the homeodomain gene hd1 and one copy of the hd2 gene in the PC9 strain, whereas the matA locus of the PC15 strain is composed by two copies of hd1.1 and hd1.2 genes (class HD1 homeodomain proteins) and one copy of hd2 gene (class HD2 proteins). Comprehensive analysis of amino acid sequences of HD1 and HD2 homeodomain proteins demonstrated that the proteins have a globular structure with the nuclear localization and contain a variable N-terminus and a more conserved DNA-binding domain with a specific conserved motif WFXNXR in the third ɑ-helix. The results suggest that multiple alleles of the matA locus of sexual compatibility in basidiomycete fungi is achieved due to both different copy number of the coding hd genes within the locus and the variability of the coding gene sequences. [ABSTRACT FROM AUTHOR]

Although the use of heterosis in maize breeding has increased crop productivity, the genetic causes underlying heterosis for nitrogen (N) use efficiency (NUE) have been insufficiently investigated. In this study, five N-response traits and five low-N-tolerance traits were investigated using two inbred line populations (ILs) consisting of recombinant inbred lines (RIL) and advanced backcross (ABL) populations, derived from crossing Ye478 with Wu312. Both populations were crossed with P178 to construct two testcross populations. IL populations, their testcross populations, and the midparent heterosis (MPH) for NUE were investigated. Kernel weight, kernel number, and kernel number per row were sensitive to N level and ILs showed higher N response than did the testcross populations. Based on a highdensity linkage map, 138 quantitative trait loci (QTL) were mapped, each explaining 5.6%-38.8% of genetic variation. There were 52, 34 and 52 QTL for IL populations, MPH, and testcross populations, respectively. The finding that 7.6% of QTL were common to the ILs and their testcross populations and that 11.7% were common to the MPH and testcross population indicated that heterosis for NUE traits was regulated by non-additive and non-dominant loci. A QTL on chromosome 5 explained 27% of genetic variation in all of the traits and Gln1-3 was identified as a candidate gene for this QTL. Genome-wide prediction of NUE traits in the testcross populations showed 14%-51% accuracy. Our results may be useful for clarifying the genetic basis of heterosis for NUE traits and the candidate gene may be used for genetic improvement of maize NUE. [ABSTRACT FROM AUTHOR]

This study deals with the making of poly(vinylidene fluoride) (PVDF) hybrid ultrafiltration (UF) membranes incorporated with zeolitic imidazolate framework‐8 (ZIF‐8) nanocrystals. The surface morphology and roughness of ZIF‐8 are explored in terms of atomic force microscopy (AFM) and scanning electron microscopy (SEM) whereas their distribution in PVDF matrix and antibacterial activity are probed by energy dispersive X‐ray (EDX) analysis and zone of inhibition test. The chemical functionality of ZIF‐8 is verified by Fourier transform infrared (FTIR) and X‐ray diffraction (XRD) spectroscopic studies. The permeability of hybrid membranes is raised to 2 wt% addition of ZIF‐8 into the PVDF matrix owing to an enhancement in hydrophilicity and porosity. The FESEM images of the top and cross‐section view make visible the formation of macrovoids with the addition of ZIF‐8. On account of high porosity and surface hydrophilicity, the pure water permeation of hybrid membranes is increased to 278.6 Lm−2 h−1. The hybrid membranes showed higher rejection and permeate flux of bovine serum albumin (BSA; 92.8 Lm−2 h−1) and humic acid (HA; 94.3 Lm−2 h−1) owing to the synergetic effect of their enhanced hydrophilicity and surface roughness. This is confirmed by the higher flux recovery ratio (FRR) and lower irreversible fouling characteristics of hybrid PVDF membranes. The atomic absorption spectroscopy (AAS) revealed the long‐standing stability of ZIF‐8 in the PVDF matrix. Among all, the PVDF hybrid membrane with 2 wt% of ZIF‐8 showed excellent permeability, antifouling, and antibiofouling ability and was found to be more effective in water treatment applications. [ABSTRACT FROM AUTHOR]

Summary: Heterosis refers to the better performance of cross progeny compared with inbred parents, and its utilization contributes greatly to agricultural production. Several hypotheses have been proposed to explain heterosis mainly including dominance, over‐dominance (or pseudo‐overdominance) and epistasis. However, systematic dissection and verification of these hypotheses are rarely documented. Here, comparison of heterosis level across different traits showed that the strong heterosis of composite traits (such as yield) could be attributed to the multiplicative effects of moderate heterosis of component traits, whether at the genome or locus level. Yield heterosis was regulated by a complex trait‐QTL network that was characterized by obvious centre‐periphery structure, hub QTL, complex up/downstream and positive/negative feedback relationships. More importantly, we showed that better‐parent heterosis on yield could be produced in a cross of two near‐isogenic lines by the pyramiding and complementation of two major heterotic QTL showing partial‐dominance on yield components. The causal gene (BnaA9.CYP78A9) of QC14 was identified, and its heterotic effect results from the heterozygous status of a CACTA‐like transposable element in its upstream regulatory region, which led to partial dominance at expression and auxin levels, thus resulting in non‐additive expression of downstream responsive genes involved in cell cycle and proliferation, eventually leading to the heterosis of cell number. Taken together, the results at the phenotypic, genetic and molecular levels were highly consistent, which demonstrated that the pyramiding effect of heterotic QTL and the multiplicative effect of individual component traits could well explain substantial parts of yield heterosis in oilseed rape. These results provide in‐depth insights into the genetic architecture and molecular mechanism of yield heterosis. [ABSTRACT FROM AUTHOR]

Heterosis contributes greatly to the worldwide agricultural yield. However, the molecular mechanism underlying heterosis remains unclear. This study took advantage of Arabidopsis intraspecific hybrids to identify heterosis-related metabolites. Forty-six intraspecific hybrids were used to examine parental effects on seed area and germination time. The degree of heterosis was evaluated based on biomass: combinations showing high heterosis of F1 hybrids exhibited a biomass increase from 6.1 to 44% over the better parent value (BPV), whereas that of the low- and no-heterosis hybrids ranged from − 19.8 to 9.8% over the BPV. Metabolomics analyses of F1 hybrids with high heterosis and those with low one suggested that changes in TCA cycle intermediates are key factors that control growth. Notably, higher fumarate/malate ratios were observed in the high heterosis F1 hybrids, suggesting they provide metabolic support associated with the increased biomass. These hybrids may produce more energy-intensive biomass by speeding up the efficiency of TCA fluxes. However, the expression levels of TCA-process-related genes in F1 hybrids were not associated with the intensity of heterosis, suggesting that the post-transcriptional or post-translational regulation of these genes may affect the productivity of the intermediates in the TCA cycle. [ABSTRACT FROM AUTHOR]

Since embryos change their morphology drastically in the gastrulation stage, mechanical characterization of young embryos is important as they also change their tissue stiffness with the stage of development. Herein, virtual compression tests were conducted assuming that the Xenopus laevis gastrula has a spherical shape with transverse anisotropy. Based on the design of experiments, we found that the Young's moduli and material anisotropy can be efficiently determined by measuring the reaction force and surface displacement when indenting the tester into an embryo. The proposed scheme may be a substantial step toward understanding the timing of cell-type specification during embryo development. [ABSTRACT FROM AUTHOR]

Heterosis is a complex biological phenomenon regulated by genetic variations and epigenetic changes. However, the roles of small RNAs (sRNAs), an important epigenetic regulatory element, on plant heterosis are still poorly understood. Here, an integrative analysis was performed with sequencing data from multi-omics layers of maize hybrids and their two homologous parental lines to explore the potential underlying mechanisms of sRNAs in plant height (PH) heterosis. sRNAome analysis revealed that 59 (18.61%) microRNAs (miRNAs) and 64,534 (54.00%) 24-nt small interfering RNAs (siRNAs) clusters were non-additively expressed in hybrids. Transcriptome profiles showed that these non-additively expressed miRNAs regulated PH heterosis through activating genes involved in vegetative growth-related pathways while suppressing those related to reproductive and stress response pathways. DNA methylome profiles showed that non-additive methylation events were more likely to be induced by non-additively expressed siRNA clusters. Genes associated with low-parental expression (LPE) siRNAs and trans-chromosomal demethylation (TCdM) events were enriched in developmental processes as well as nutrients and energy metabolism, whereas genes associated with high-parental expression (HPE) siRNAs and trans-chromosomal methylation (TCM) events were gathered in stress response and organelle organization pathways. Our results provide insights into the expression and regulation patterns of sRNAs in hybrids and help to elucidate their potential targeting pathways contributing to PH heterosis. [ABSTRACT FROM AUTHOR]

[Objectives] This study aimed to investigate the sequence structure and function of Myostatin (MSTN) gene in the hybrid grouper (Epinephelus fuscoguttatus, x Epinephelus polyphekadion, ). [Methods] Genetic DNA samples were extracted from the caudal fins of the hybrid grouper and its parents to amplify their MSTN genes. Then, MSTN gene sequences were analyzed using bioinformatics tools to predict their protein structures and functions. [Results] The hybrid grouper and its parents shared the same MSTN gene structure, consisting of three exons and two introns. Nucleotide sequence of the gene could be translated into 376 amino acids, including an N-terminal signal peptide, a proteolytic processing site (RXXR motif), and nine conserved cysteine residues at C-terminal, which were the typical features of transforming growth factor beta (TGF-β) superfamily proteins. Alignment of protein sequence showed that MSTN was highly conserved between the hybrid grouper and its parents. Especially, exon 3, an important functional domain, exhibited a sequence similarity of 100% among them. In addition, four variable amino acid residues were detected in exon 2 at positions 141, 153, 185 and 186 in the hybrid grouper, but they did not affect the secondary structure of the protein. [Conclusion] These results wiil provide molecular information for future investigation on the growth and heterosis of hybrid grouper species, and on the roles of MSTN gene in regulating the growth traits of the hybrid grouper. [ABSTRACT FROM AUTHOR]

Continuous monitoring of tissue microphysiology is a key enabling feature of the organ-on-chip (OoC) approach for in vitro drug screening and disease modeling. Integrated sensing units are particularly convenient for microenvironmental monitoring. However, sensitive in vitro and real-time measurements are challenging due to the inherently small size of OoC devices, the characteristics of commonly used materials, and external hardware setups required to support the sensing units. Here we propose a silicon-polymer hybrid OoC device that encompasses transparency and biocompatibility of polymers at the sensing area, and has the inherently superior electrical characteristics and ability to house active electronics of silicon. This multi-modal device includes two sensing units. The first unit consists of a floating-gate field-effect transistor (FG-FET), which is used to monitor changes in pH in the sensing area. The threshold voltage of the FG-FET is regulated by a capacitively-coupled gate and by the changes in charge concentration in close proximity to the extension of the floating gate, which functions as the sensing electrode. The second unit uses the extension of the FG as microelectrode, in order to monitor the action potential of electrically active cells. The layout of the chip and its packaging are compatible with multi-electrode array measurement setups, which are commonly used in electrophysiology labs. The multi-functional sensing is demonstrated by monitoring the growth of induced pluripotent stem cell-derived cortical neurons. Our multi-modal sensor is a milestone in combined monitoring of different, physiologically-relevant parameters on the same device for future OoC platforms. [ABSTRACT FROM AUTHOR]

PH13-8Mo stainless steel has been widely used in aerospace, petroleum and marine construction, obtaining continuous investigation attention in recent years. Based on the response of a hierarchical martensite matrix and possible reversed austenite, a systematic investigation of the evolution of the toughening mechanisms in PH13-8Mo stainless steel as a function of aging temperature was carried out. It showed there was a desirable combination of high yield strength (~1.3 GPa) and V-notched impact toughness (~220 J) after aging between 540 and 550 °C. With the increase of aging temperature, the martensite matrix was recovered in terms of the refined sub-grains and higher ratio of high-angle grain boundaries (HAGBs). It should be noted there was a reversion of martensite to form austenite films subjected to aging above 540 °C; meanwhile, the NiAl precipitates maintained a well-coherent orientation with the matrix. Based on the post mortem analysis, there were three stages of the changing main toughening mechanisms: Stage I: low-temperature aging at around 510 °C, where the HAGBs contributed to the toughness by retarding the advance of cracks; Stage II: intermediate-temperature aging at around 540 °C, where the recovered laths embedded by soft austenite facilitated the improvement of toughness by synergistically increasing the advance path and blunting the crack tips; and Stage III: without the coarsening of NiAl precipitates around 560 °C, more inter-lath reversed austenite led to the optimum toughness, relying on "soft barrier" and transformation-induced plasticity (TRIP) effects. [ABSTRACT FROM AUTHOR]

Background: Soil salinization is a major abiotic environmental stress factor threatening crop production throughout the world. Salt stress drastically affects the growth, development, and grain yield of rice (Oryza sativa L.), and the improvement of rice tolerance to salt stress is a desirable approach for meeting increasing food demand. Receptor-like cytoplasmic kinases (RLCKs) play essential roles in plant growth, development and responses to environmental stresses. However, little is known about their functions in salt stress. Previous reports have demonstrated that overexpression of an RLCK gene SALT TOLERANCE KINASE (STK) enhances salt tolerance in rice, and that STK may regulate the expression of GST (Glutathione S-transferase) genes. Results: The expression of STK was rapidly induced by ABA. STK was highest expressed in the stem at the heading stage. STK was localized at the plasma membrane. Overexpression of STK in rice increased tolerance to salt stress and oxidative stress by increasing ROS scavenging ability and ABA sensitivity. In contrast, CRISPR/Cas9-mediated knockout of STK increased the sensitivity of rice to salt stress and oxidative stress. Transcriptome sequencing analysis suggested that STK increased the expression of GST genes (LOC_Os03g17480, LOC_Os10g38140 and LOC_Os10g38710) under salt stress. Reverse transcription quantitative PCR (RT-qPCR) suggested that four stress-related genes may be regulated by STK including OsABAR1, Os3BGlu6, OSBZ8 and OsSIK1. Conclusions: These findings suggest that STK plays a positive regulatory role in salt stress tolerance by inducing antioxidant defense and associated with the ABA signaling pathway in rice. [ABSTRACT FROM AUTHOR]

Ranunculus is a well-known flower having a great economic value for its bright colors and vibrant patterns. Given the importance of the ranunculus cut flower, conducting this study elucidated the genetic behavior and variability of various morphological attributes in ranunculus genotypes. Assessment of six ranunculus genotypes measured germination percentage (%), days to emergence, days to maturity, stem length, stem thickness, flowers per plant, flower size, and flower duration on the plant. Analysis of variance depicted significant variation in all the studied traits except days to emergence, number of stems, and germination percentage. Clustering ranunculus genotype with the Euclidean distances-based hierarchical clustering resulted in two clusters of the genotype. One genotype (red) did not join any group, indicating an early separation of this genotype during the evolution of Ranunculus species. Correlation analysis showed that most studied traits negatively correlated, with only a few positively correlating traits. The number of flowers per plant and stem length showed a d positive correlation (0.7437 and 0.8064, respectively). Overall, the results showed that the red, yellow, and rose genotypes are the best performers for cultivation to produce betterquality flowers. Genetic analysis using line × tester analysis revealed higher values for the SCA component than GCA, suggesting non-additive gene action for most traits under study. Moreover, the hybrids developed in the current study developed new color combinations/shades. These hybrids could further benefit ranunculus stable variant improvement. [ABSTRACT FROM AUTHOR]

In Chinese cabbage breeding, hybrids have made a terrific contribution due to heterosis, the superior performance of offspring compared to their inbred parents. Since the development of new, top-performing hybrids requires a large scale of human and material resources, the prediction of hybrid performance is of utmost interest to plant breeders. In our research, leaf transcriptome data from eight parents were used to investigate if they might be employed as markers to predict hybrid performance and heterosis. In Chinese cabbage, heterosis of plant growth weight (PGW) and heterosis of head weight (HW) were more obvious than other traits. The number of differential expression genes (DEGs) between parents was related to the PGW, length of the biggest outer leaf (LOL), leaf head height (LHH), leaf head width (LHW), HW, leaf number of head (LNH) and plant height (PH) of hybrids, and up-regulated DEGs number was also associated with these traits. Euclidean and binary distances of parental gene expression levels were significantly correlated with the PGW, LOL, LHH, LHW, HW and PH of hybrids. Additionally, there was a significant correlation between the parental expression levels of multiple genes involved in the ribosomal metabolic pathway and hybrid observations and heterosis in PGW, with the BrRPL23A gene showing the highest correlation with the MPH of PGW(r = 0.75). Therefore, leaf transcriptome data can preliminarily predict the hybrid performance and select parents in Chinese cabbage. [ABSTRACT FROM AUTHOR]

Heterosis and polyploidy have an overwhelming influence on plant evolution. Recently, polyploid rice hybrids have been used to breed new rice varieties because they combine the advantages of both heterosis and polyploidy. In this study, we generated six rice lines: autotetraploid rice hybrids and their autotetraploid parents, diploid donors, and hybrids of the diploid donors. To investigate the molecular mechanism controlling the effects of both hybridization and polyploidization, we performed bisulfite and RNA sequencing on young panicles at the pollen meiosis stage to compare the DNA metabolomes and transcriptomes among the six rice lines. The hybrids lines were hypermethylated compared to their corresponding parents and the autotetraploid lines showed globally increased DNA methylation of their transposable elements compared to the diploid donors. The alteration in DNA methylation level corresponded to the differential gene expressions among the rice genotypes, suggesting that methylation changes induced by polyploidization and hybridization may affect gene expression. Groups of gene candidates were identified that may be associated with heterosis and polyploidy. Our results provide DNA information that can be used to investigate epigenetic modification during heterosis and polyploidy in rice. [ABSTRACT FROM AUTHOR]

The cytoplasmic male sterility (CMS) and nuclear-controlled fertility restoration system is a favorable tool for the utilization of heterosis in plant hybrid breeding. Many restorer-of-fertility (Rf) genes have been characterized in various species over the decades, but more detailed work is needed to investigate the fertility restoration mechanism. Here, we identified an alpha subunit of mitochondrial processing peptidase (MPPA) that is involved in the fertility restoration process in Honglian-CMS rice. MPPA is a mitochondrial localized protein and interacted with the RF6 protein encoded by the Rf6. MPPA indirectly interacted with hexokinase 6, namely another partner of RF6, to form a protein complex with the same molecular weight as the mitochondrial F1F0-ATP synthase in processing the CMS transcript. Loss-of-function of MPPA resulted in a defect in pollen fertility, the mppa+/− heterozygotes showed semi-sterility phenotype and the accumulation of CMS-associated protein ORFH79, showing restrained processing of the CMS-associated atp6-OrfH79 in the mutant plant. Taken together, these results threw new light on the process of fertility restoration by investigating the RF6 fertility restoration complex. They also reveal the connections between signal peptide cleavage and the fertility restoration process in Honglian-CMS rice. [ABSTRACT FROM AUTHOR]

The present study was aimed to assess the molecular genetic diversity in 14 parental lines (10 maintainers and 4 restorers) of sunflower crop using 51 SSR markers. A total of 147 alleles were produced with the range of 1-6 alleles per locus. The polymorphic information content (PIC) values ranged from 0.12(ORS1198 in LG5) to 0.74(ORS384 in LG15) with an average PIC of 0.51. A phylogenetic tree was constructed by neighbour-joining method which grouped the parents into four clusters. Among the maintainer and restorer combinations, the dissimilarity index was maximum between CMS 519B and CSFI 99 (0.67) which indicateed high divergence between them. Lower dissimilarity value was observed between RCR CMS 38B and LTRR 341 (0.40) suggested less divergence between them. Mahalanobis D2 analysis was also carried out among the parental lines. The D2 analysis grouped the parental lines into six clusters. Among them genotype pairs CMS104B vs RHA 1-1 and CSFI 99 vs LTRR341 had highest and lowest D2 values respectively. Dissimilarity and D2 values for parental combinations, mean performance, mid and better parental heterosis of 40 hybrids for yield and its component traits were subjected to simple correlation analysis. The D2 analysis did not show any association with performance of hybrids. However, the dissimilarity values showed association with hybrid performance and heterosis for plant height and volume weight. Hence, the present study indicated that the selection of parental genotypes with high molecular diversity could result in improved performance of plant height and volume weight in sunflower hybrids. However further study is required with multi environment data sets. [ABSTRACT FROM AUTHOR]

Key message: Using map-based cloning and transgenic transformation, we revealed that glycogen kinase synthase 3-like kinase, BnaC01.BIN2, modulates plant height and yield in rapeseed. The modification of plant height is one of the most important goals in rapeseed breeding. Although several genes that regulate rapeseed plant height have been identified, the genetics mechanisms underlying rapeseed plant height regulation remain poorly understood, and desirable genetic resources for rapeseed ideotype breeding are scarce. Here, we map-based cloned and functionally verified that the rapeseed semi-dominant gene, BnDF4, greatly affects rapeseed plant height. Specifically, BnDF4 encodes brassinosteroid (BR)-insensitive 2, a glycogen synthase kinase 3 primarily expressed in the lower internodes to modulate rapeseed plant height by blocking basal internode-cell elongation. Transcriptome data showed that several cell expansion-related genes involving auxin and BRs pathways were significantly downregulated in the semi-dwarf mutant. Heterozygosity in the BnDF4 allele results in small stature with no marked differences in other agronomic traits. Using BnDF4 in the heterozygous condition, the hybrid displayed strong yield heterosis through optimum intermediate plant height. Our results provide a desirable genetic resource for breeding semi-dwarf rapeseed phenotypes and support an effective strategy for breeding rapeseed hybrid varieties with strong yield heterosis. [ABSTRACT FROM AUTHOR]

Heterosis or hybrid vigor refers to the superior phenotypic traits of hybrids relative to their parental inbred lines. An imbalance between the expression levels of two parental alleles in the F1 hybrid has been suggested as a mechanism of heterosis. Here, based on genome-wide allele-specific expression analysis using RNA sequencing technology, 1689 genes exhibiting genotype-dependent allele-specific expression (genotype-dependent ASEGs) were identified in the embryos, and 1390 genotype-dependent ASEGs in the endosperm, of three maize F1 hybrids. Of these ASEGs, most were consistent in different tissues from one hybrid cross, but nearly 50% showed allele-specific expression from some genotypes but not others. These genotype-dependent ASEGs were mostly enriched in metabolic pathways of substances and energy, including the tricarboxylic acid cycle, aerobic respiration, and energy derivation by oxidation of organic compounds and ADP binding. Mutation and overexpression of one ASEG affected kernel size, which indicates that these genotype-dependent ASEGs may make important contributions to kernel development. Finally, the allele-specific methylation pattern on genotype-dependent ASEGs indicated that DNA methylation plays a potential role in the regulation of allelic expression for some ASEGs. In this study, a detailed analysis of genotype-dependent ASEGs in the embryo and endosperm of three different maize F1 hybrids will provide an index of genes for future research on the genetic and molecular mechanism of heterosis. [ABSTRACT FROM AUTHOR]

It is crucial to understand how targeted traits in a hybrid breeding program are influenced by gene activity and combining ability. During the three growing seasons of 2015, 2016, and 2017, a field study was conducted with twelve cotton genotypes, comprised of four testers and eight lines. Thirty-two F1 crosses were produced in the 2015 breeding season using the line x tester mating design. The twelve genotypes and their thirty-two F1 crosses were then evaluated in 2016 and 2017. The results demonstrated highly significant differences among cotton genotypes for all the studied traits, showing a wide range of genetic diversity in the parent genotypes. Additionally, the line-x-tester interaction was highly significant for all traits, suggesting the impact of both additive and non-additive variations in gene expression. Furthermore, the thirty-two cotton crosses showed high seed cotton output, lint cotton yield, and fiber quality, such as fiber length values exceeding 31 mm and a fiber strength above 10 g/tex. Accordingly, selecting lines and testers with high GCA effects and crosses with high SCA effects would be an effective approach to improve the desired traits in cotton and develop new varieties with excellent yield and fiber quality. [ABSTRACT FROM AUTHOR]

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Single cells exhibit a significant amount of variability in transcript levels, which arises from slow, stochastic transitions between gene expression states. Elucidating the nature of these states and understanding how transition rates are affected by different regulatory mechanisms require state-of-the-art methods to infer underlying models of gene expression from single cell data. A Bayesian approach to statistical inference is the most suitable method for model selection and uncertainty quantification of kinetic parameters using small data sets. However, this approach is impractical because current algorithms are too slow to handle typical models of gene expression. To solve this problem, we first show that time-dependent mRNA distributions of discrete-state models of gene expression are dynamic Poisson mixtures, whose mixing kernels are characterized by a piecewise deterministic Markov process. We combined this analytical result with a kinetic Monte Carlo algorithm to create a hybrid numerical method that accelerates the calculation of time-dependent mRNA distributions by 1000-fold compared to current methods. We then integrated the hybrid algorithm into an existing Monte Carlo sampler to estimate the Bayesian posterior distribution of many different, competing models in a reasonable amount of time. We demonstrate that kinetic parameters can be reasonably constrained for modestly sampled data sets if the model is known a priori. If there are many competing models, Bayesian evidence can rigorously quantify the likelihood of a model relative to other models from the data. We demonstrate that Bayesian evidence selects the true model and outperforms approximate metrics typically used for model selection. [ABSTRACT FROM AUTHOR]