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1.
Plant Biotechnol J ; 2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38761386

RESUMO

Seed vigour, including rapid, uniform germination and robust seedling establishment under various field conditions, is becoming an increasingly essential agronomic trait for achieving high yield in crops. However, little is known about this important seed quality trait. In this study, we performed a genome-wide association study to identify a key transcription factor ZmRap2.7, which regulates seed vigour through transcriptionally repressing expressions of three ABA signalling genes ZmPYL3, ZmPP2C and ZmABI5 and two phosphatidylethanolamine-binding genes ZCN9 and ZCN10. In addition, ZCN9 and ZCN10 proteins could interact with ZmPYL3, ZmPP2C and ZmABI5 proteins, and loss-of-function of ZmRap2.7 and overexpression of ZCN9 and ZCN10 reduced ABA sensitivity and seed vigour, suggesting a complex regulatory network for regulation of ABA signalling mediated seed vigour. Finally, we showed that four SNPs in ZmRap2.7 coding region influenced its transcriptionally binding activity to the downstream gene promoters. Together with previously identified functional variants within and surrounding ZmRap2.7, we concluded that the distinct allelic variations of ZmRap2.7 were obtained independently during maize domestication and improvement, and responded separately for the diversities of seed vigour, flowering time and brace root development. These results provide novel genes, a new regulatory network and an evolutional mechanism for understanding the molecular mechanism of seed vigour.

2.
Brain ; 146(9): 3576-3586, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-36864683

RESUMO

The debilitating symptoms of Parkinson's disease, including the hallmark slowness of movement, termed bradykinesia, were described more than 100 years ago. Despite significant advances in elucidating the genetic, molecular and neurobiological changes in Parkinson's disease, it remains conceptually unclear exactly why patients with Parkinson's disease move slowly. To address this, we summarize behavioural observations of movement slowness in Parkinson's disease and discuss these findings in a behavioural framework of optimal control. In this framework, agents optimize the time it takes to gather and harvest rewards by adapting their movement vigour according to the reward that is at stake and the effort that needs to be expended. Thus, slow movements can be favourable when the reward is deemed unappealing or the movement very costly. While reduced reward sensitivity, which makes patients less inclined to work for reward, has been reported in Parkinson's disease, this appears to be related mainly to motivational deficits (apathy) rather than bradykinesia. Increased effort sensitivity has been proposed to underlie movement slowness in Parkinson's disease. However, careful behavioural observations of bradykinesia are inconsistent with abnormal computations of effort costs due to accuracy constraints or movement energetic expenditure. These inconsistencies can be resolved when considering that a general disability to switch between stable and dynamic movement states can contribute to an abnormal composite effort cost related to movement in Parkinson's disease. This can account for paradoxical observations such as the abnormally slow relaxation of isometric contractions or difficulties in halting a movement in Parkinson's disease, both of which increase movement energy expenditure. A sound understanding of the abnormal behavioural computations mediating motor impairment in Parkinson's disease will be vital for linking them to their underlying neural dynamics in distributed brain networks and for grounding future experimental studies in well-defined behavioural frameworks.


Assuntos
Doença de Parkinson , Humanos , Doença de Parkinson/complicações , Hipocinesia/etiologia , Movimento , Encéfalo
3.
BMC Public Health ; 24(1): 546, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38383370

RESUMO

BACKGROUND: The aim of our study was to determine how six mood indicators (vigour, fatigue, depression, anger, confusion, tension) depend on moderate to vigorous physical activity, walking time and sedentary time at work, after working hours and during leisure time, in men and women of different age groups. METHODS: A total of 1,140 individuals aged 18 to 64 years participated in the study. The participants were enrolled in this cross-sectional survey using a snowball sampling method. An online questionnaire was shared through popular social networks and emails within the period October 2019 to June 2020. Mood responses were assessed using The Brunel Mood Scale-LTU. Physical activity was assessed using the long International Physical Activity Questionnaire. Descriptive analysis, a two-way analysis of variance, and linear regression analysis were used to interpret the data. RESULTS: The survey results showed that vigour and fatigue correlated significantly only with leisure-time moderate to vigorous physical activity. The present results show a significant positive correlation between women and men moods and leisure-time moderate to vigorous physical activity, the length of time walking to work and back home, and negative correlation between moods and leisure-time sedentary behaviour. However, there was no significant correlation between moods and work-related moderate to vigorous physical activity and household moderate to vigorous physical activity, walking at work, and sitting duration at work. CONCLUSIONS: This study provides theoretical implications of the physical activity paradox, justifying the benefits of moderate to vigorous physical activity practiced in different circumstances. According to the regression analysis, exercising men in all age groups moved the most (had a higher moderate to vigorous physical activity level) during leisure time, the highest work-related moderate to vigorous physical activity was observed in men and women with lower education, and the highest household moderate to vigorous physical activity was observed in older age men and women living in rural areas. Clinicians and leaders at all levels of health care should consider the greater importance of leisure-time physical activity for mental health when choosing the most targeted physical activity recommendations for mood profile improvement in men and women of different age groups.


Assuntos
Atividades de Lazer , Atividade Motora , Masculino , Humanos , Feminino , Estudos Transversais , Atividade Motora/fisiologia , Atividades de Lazer/psicologia , Exercício Físico/fisiologia , Fadiga
4.
J Gambl Stud ; 40(1): 131-157, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37270469

RESUMO

Attempts to obtain rewards are not always successful. Despite investing much time, effort, or money, sometimes individuals may not obtain any reward. Other times they may obtain some reward, but the obtained reward may be smaller than their initial investment, such as partial wins in gambling. It remains unclear how such ambiguous outcomes are appraised. To address this question, we systematically varied the payoffs for different outcomes in a computerized scratch card task across three experiments. To test outcome appraisal, we used response vigor as a novel proxy. In the scratch card task, participants turned three cards one by one. Depending on the turned cards, they either received an amount that was higher than the wager (win), an amount lower than the wager (partial win), or nothing (loss). Overall, participants responded to partial wins more slowly than losses, but more quickly than wins. Partial wins were therefore appraised to be better than losses, but worse than wins. Importantly, further analyses showed that outcome appraisal was not based on the net win or loss amount. Instead, participants primarily used the configuration of turned cards as a cue for the relative rank of an outcome within a specific game. Outcome appraisals thus utilize simple heuristic rules, rely on salient information (such as outcome-related cues in gambling), and are specific to a local context. Together, these factors may contribute to the misperception of partial wins as real wins in gambling. Future work may examine how outcome appraisal may be modulated by the salience of certain information, and investigate the appraisal process in contexts beyond gambling.


Assuntos
Jogo de Azar , Humanos , Jogo de Azar/psicologia , Sinais (Psicologia) , Investimentos em Saúde , Recompensa
5.
Eur J Neurosci ; 58(8): 3751-3784, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37752810

RESUMO

Receipt of an intense reward boosts motivation to work for more of that reward. This phenomenon is called the priming effect of rewards. Using a novel measurement method, we show that the priming effect of rewarding electrical brain stimulation depends on the cost, as well as on the strength, of the anticipated reward. Previous research on the priming effect of electrical brain stimulation utilized a runway paradigm in which running speed serves as the measure of motivation. In the present study, the measure of motivation was the vigour with which rats executed a two-lever response chain, in a standard operant-conditioning chamber, to earn rewarding electrical stimulation of the lateral hypothalamus. In a second experiment, we introduced a modification that entails self-administered priming stimulation and alternating blocks of primed and unprimed trials. Reliable, consistent priming effects of substantial magnitude were obtained in the modified paradigm, which is closely analogous to the runway paradigm. In a third experiment, the modified paradigm served to assess the dependence of the priming effect on dopamine D2-like receptors. The priming effect proved resilient to the effect of eticlopride, a selective D2-like receptor antagonist. These results are discussed within the framework of a new model of brain reward circuitry in which non-dopaminergic medial forebrain bundle fibers and dopamine axons provide parallel inputs to the final common paths for reward and incentive motivation.

6.
Mol Biol Rep ; 50(10): 8177-8188, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37555871

RESUMO

BACKGROUND: The eventual shifting of cultivation method from puddle transplanted rice to direct-seeded rice (DSR) to save water prompted researchers to develop DSR-suitable varieties. To achieve this, identification of molecular markers associated with must-have traits for DSR, especially early seedling vigour related traits is crucial. METHODS AND RESULTS: In the present investigation, the haplotype analysis using flanking markers of three important quantitative trait loci (QTLs) for early seedling vigour-related traits viz., qSV-6a (RM204 and RM402) for root length; qVI (RM20429 and RM3) for seedling vigour index; qGP-6 (RM528 and RM400) for germination percentage revealed that the marker alleles were found to show significant associations with qVI and qGP-6 QTLs. The majority of genotypes with high early seedling vigour are with qVIHap-1 (220 and 160 bp) and qGPHap-1 (290 and 290 bp). The rice genotypes with superior haplotypes for early seedling vigour are BMF536, BMF540, BMF525, MM129 and MDP2. CONCLUSIONS: In conclusion, here we demonstrated that the markers RM20429 and RM3 are associated with seedling vigour index whereas RM528 and RM400 are associated with germination percentage. Therefore, these markers can be utilized to develop varieties suitable for DSR conditions through haplotype-based breeding. In addition, the rice genotypes with superior haplotypes can be of immense value to use as donors or can be released as varieties also under DSR conditions.


Assuntos
Oryza , Locos de Características Quantitativas , Locos de Características Quantitativas/genética , Plântula/genética , Oryza/genética , Haplótipos/genética , Melhoramento Vegetal
7.
Reprod Domest Anim ; 58(6): 734-739, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36929097

RESUMO

The objective of this study was to compare the late embryo mortality (LEM) rate (losses approximately between 32 and 53 days of gestation) and Pregnancy Specific Protein B (PSPB) and progesterone (P4) concentrations on day 32 post AI in Holstein cows bred with either Holstein or Limousine semen. A sample size of 1082 cows per group diagnosed pregnant between 28- and 35-days post breeding was calculated. The study consisted of evaluating LEM (%) in a cohort of Holstein cows bred with Holstein semen (HO × HO) or Limousine semen (HO × LM), to compare pregnancy loss from 28 to 35 days post breeding to 50-57 days post breeding. A logistic regression model to compare embryo losses was developed considering as main explanatory variable the cohort (HO × HO embryo vs. HO × LM embryo), correcting by lactation number, breeding season, days to breeding and AI technician. HO × HO embryos had greater LEM (15.16%) than HO × LM embryos (9.79%). Cows bred in summertime had higher LEM (15.23%) than cows bred in no-summertime (9.88%). There were no differences among AI technicians. Within summertime there was no difference in LEM (%) between groups within each lactation number; yet, within no-summertime, LEM (%) was higher in HO × HO than HO × LM within each lactation number. Pregnancy SPB optical densities were significantly greater in the HO × HO than in the HO × LM (p = .023) group; yet, the concentration of P4 was not different between groups (p > .05).


Assuntos
Doenças dos Bovinos , Preservação do Sêmen , Gravidez , Feminino , Bovinos , Animais , Preservação do Sêmen/veterinária , Inseminação Artificial/veterinária , Lactação , Progesterona , Perda do Embrião/veterinária
8.
Proc Biol Sci ; 289(1978): 20220831, 2022 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-35858074

RESUMO

Most herbivorous insects can only survive on a small subset of the plant species in its environment. Consequently, adult females have evolved sophisticated sensory recognition systems enabling them to find and lay eggs on plants supporting offspring development. This leads to the preference-performance or 'mother knows best' hypothesis that insects should be attracted to host plants that confer higher offspring survival. Previous work shows insects generally select plant species that are best for larval survival, although this is less likely for crops or exotic host plants. Even within a species, however, individual plants can vary greatly in potential suitability depending on age, access to water or nutrients or attack by pathogens or other herbivores. Here, I systematically review 71 studies on 62 insect species testing the preference-performance hypothesis with sets of plants varying in age, stress, fungal/microbial infection or herbivore damage. Altogether, 77% of insects tested with a native host (N = 43) allocated their eggs to plants best for offspring development, as did 64% (N = 22) of insects tested with an exotic host. Results were similar across plant age, stress, disease and damage categories. These findings show adaptive maternal behaviour in insects occurs for both host species and variation among individual plants.


Assuntos
Insetos , Oviposição , Animais , Feminino , Herbivoria , Larva , Plantas
9.
Plant Biotechnol J ; 20(9): 1701-1715, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35534989

RESUMO

Chickpea production is vulnerable to drought stress. Identifying the genetic components underlying drought adaptation is crucial for enhancing chickpea productivity. Here, we present the fine mapping and characterization of 'QTL-hotspot', a genomic region controlling chickpea growth with positive consequences on crop production under drought. We report that a non-synonymous substitution in the transcription factor CaTIFY4b regulates seed weight and organ size in chickpea. Ectopic expression of CaTIFY4b in Medicago truncatula enhances root growth under water deficit. Our results suggest that allelic variation in 'QTL-hotspot' improves pre-anthesis water use, transpiration efficiency, root architecture and canopy development, enabling high-yield performance under terminal drought conditions. Gene expression analysis indicated that CaTIFY4b may regulate organ size under water deficit by modulating the expression of GRF-INTERACTING FACTOR1 (GIF1), a transcriptional co-activator of Growth-Regulating Factors. Taken together, our study offers new insights into the role of CaTIFY4b and on diverse physiological and molecular mechanisms underpinning chickpea growth and production under specific drought scenarios.


Assuntos
Cicer , Secas , Adaptação Fisiológica/genética , Cicer/genética , Variação Genética/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Água/metabolismo
10.
Plant Biotechnol J ; 20(7): 1346-1362, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35315188

RESUMO

The cultivation of rice varieties with high seed vigour is vital for the direct seeding of rice, and the molecular basis of regulation of seed vigour remains elusive. Here, we cloned a new gene OsHIPL1, which encodes hedgehog-interacting protein-like 1 protein as a causal gene of the major QTL qSV3 for rice seed vigour. OsHIPL1 was mainly localized in the plasma membrane and nucleus. RNA sequencing (RNA-seq) revealed that the ABA-related genes were involved in the OsHIPL1 regulation of seed vigour in rice. The higher levels of endogenous ABA were measured in germinating seeds of OsHIPL1 mutants and NIL-qsv3 line compared to IR26 plants, with two up-regulated ABA biosynthesis genes (OsZEP and OsNCED4) and one down-regulated ABA catabolism gene OsABA8ox3. The expression of abscisic acid-insensitive 3 (OsABI3), OsABI4 and OsABI5 was significantly up-regulated in germinating seeds of OsHIPL1 mutants and NIL-qsv3 line compared to IR26 plants. These results indicate that the regulation of seed vigour of OsHIPL1 may be through modulating endogenous ABA levels and altering OsABIs expression during seed germination in rice. Meanwhile, we found that OsHIPL1 interacted with the aquaporin OsPIP1;1, then affected water uptake to promote rice seed germination. Based on analysis of single-nucleotide polymorphism data of rice accessions, we identified a Hap1 haplotype of OsHIPL1 that was positively correlated with seed germination. Our findings showed novel insights into the molecular mechanism of OsHIPL1 on seed vigour.


Assuntos
Oryza , Ácido Abscísico/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Germinação/genética , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Oryza/metabolismo , Sementes/metabolismo
11.
Plant Biotechnol J ; 20(3): 485-498, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34665915

RESUMO

Seed vigour is an imperative trait for the direct seeding of rice. In this study, we examined the genetic regulation of seedling percentage at the early germination using a genome-wide association study in rice. One major quantitative trait loci qSP3 for seedling percentage was identified, and the candidate gene was validated as qSP3, encoding a cupin domain protein OsCDP3.10 for the synthesis of 52 kDa globulin. Disruption of this gene in Oscdp3.10 mutants reduced the seed vigour, including the germination potential and seedling percentage, at the early germination in rice. The lacking accumulation of 52 kDa globulin was observed in the mature grains of the Oscdp3.10 mutants. The significantly lower amino acid contents were observed in the mature grains and the early germinating seeds of the Oscdp3.10 mutants compared with those of wild-type. Rice OsCDP3.10 regulated seed vigour mainly via modulating the amino acids e.g. Met, Glu, His, and Tyr that contribute to hydrogen peroxide (H2 O2 ) accumulation in the germinating seeds. These results provide important insights into the application of seed priming with the amino acids and the selection of OsCDP3.10 to improve seed vigour in rice.


Assuntos
Oryza , Aminoácidos/metabolismo , Estudo de Associação Genômica Ampla , Germinação/genética , Oryza/metabolismo , Plântula/genética , Sementes/metabolismo
12.
J Exp Bot ; 73(8): 2499-2510, 2022 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-35195714

RESUMO

Six cycles of recurrent selection for early shoot vigour in wheat resulted in significant increases in leaf width and shoot biomass. Here, in replicated controlled-environment studies, the effect of early shoot vigour on root biomass, rhizosheath size, root hair length, and cell size in the roots and leaves was examined across different cycles of selection. Increased shoot vigour was associated with greater root biomass, larger rhizosheath size, and longer root hairs. Our findings demonstrate that rhizosheath size was a reliable surrogate for root hair length in this germplasm. Examination of the root epidermis revealed that the 'cell body' of the trichoblasts (hair-forming cells) and the atrichoblasts (non-hair-forming cells) decreased in size as shoot vigour increased. Therefore, in higher vigour germplasm, longer root hairs emerged from smaller trichoblasts so that total trichoblast volume (root hair plus cell body) was generally similar regardless of shoot vigour. Similarly, the sizes of the four main cell types on the leaf epidermis became progressively smaller as shoot vigour increased, which also increased stomatal density. The relationship between shoot vigour and root traits is considered, and the potential contribution of below-ground root traits to performance and competitiveness of high vigour germplasm is discussed.


Assuntos
Raízes de Plantas , Triticum , Tamanho Celular , Células Epidérmicas , Epiderme , Folhas de Planta , Raízes de Plantas/metabolismo , Triticum/genética , Triticum/metabolismo
13.
J Adv Nurs ; 78(8): 2339-2348, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34989434

RESUMO

AIMS: To examine: (1) a motivational pathway where head nurse proactive leadership and nurse vigour are linked, which in turn correlates to missed nursing care, and might be moderated by workload; and (2) an energetic pathway where workload and nurse exhaustion are linked, which in turn correlates to missed nursing care, and might be moderated by head nurse proactive leadership. DESIGN: A cross-sectional design, with nurses nested in wards. METHODS: During 2018, 196 nurses from 37 wards completed questionnaires that included the 22-item MISSCARE survey; the 6-item Work Demand subscale; the 10-item Proactivity Personality scale; the 5-item Exhaustion subscale of the Maslach Burnout Inventory; the 5-item Vigour subscale of the Work Engagement scale; and nurse's and head nurse's sociodemographic characteristics. Moderation-mediation models were performed using mixed-linear model analyses. RESULTS: A moderation-mediation motivational pathway was supported. Specifically, nurse vigour was higher under low workload when head nurse proactive leadership was high (ß = -.09, p = .050), which in turn was associated with lower missed nursing care (ß = -.10, p = .045). Yet, a moderation-mediation energetic pathway was not supported. Specifically, nurse exhaustion was lower under low workload when head nurse proactive leadership was high (ß = .14, p = .032), but no association was found between exhaustion and missed nursing care. CONCLUSIONS: This study shows that there is a significant role for nurse agency and nurse ability to cope with scarce resources. IMPACT: To date, research has focused mainly on the assumption that missed nursing care is a result of scarce resources. Findings indicate that even under scarce resources, nurses can be motivated to reduce missed nursing care. Emphasis should be placed on promoting and maximizing nurse motivation. This can be achieved by developing and implementing interventions of proactive leadership of head nurses.


Assuntos
Esgotamento Profissional , Cuidados de Enfermagem , Recursos Humanos de Enfermagem Hospitalar , Estudos Transversais , Humanos , Motivação , Supervisão de Enfermagem , Inquéritos e Questionários
14.
Genomics ; 113(6): 4227-4236, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34774680

RESUMO

Seedling vigour is an important agronomic trait and is gaining attention in Asian rice (Oryza sativa) as cultivation practices shift from transplanting to forms of direct seeding. To understand the genetic control of rice seedling vigour in dry direct seeded (aerobic) conditions we measured multiple seedling traits in 684 accessions from the 3000 Rice Genomes (3K-RG) population in both the laboratory and field at three planting depths. Our data show that phenotyping of mesocotyl length in laboratory conditions is a good predictor of field performance. By performing a genome wide association study, we found that the main QTL for mesocotyl length, percentage seedling emergence and shoot biomass are co-located on the short arm of chromosome 7. We show that haplotypes in the indica subgroup from this region can be used to predict the seedling vigour of 3K-RG accessions. The selected accessions may serve as potential donors in genomics-assisted breeding programs.


Assuntos
Oryza , Plântula , Estudo de Associação Genômica Ampla , Haplótipos , Oryza/genética , Fenômica , Melhoramento Vegetal , Locos de Características Quantitativas , Plântula/genética
15.
Int J Mol Sci ; 23(23)2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36499279

RESUMO

Nitric oxide (NO) has been recognized as a gasotransmitter in the mainstream of plant research since the beginning of the 21st century. It is produced in plant tissue and the environment. It influences plant physiology during every ontogenetic stage from seed germination to plant senescence. In this review, we demonstrate the increased interest in NO as a regulatory molecule in combination with other signalling molecules and phytohormones in the information network of plant cells. This work is a summary of the current knowledge on NO action in seeds, starting from seed pretreatment techniques applied to increase seed quality. We describe mode of action of NO in the regulation of seed dormancy, germination, and aging. During each stage of seed physiology, NO appears to act as a key agent with a predominantly beneficial effect.


Assuntos
Óxido Nítrico , Dormência de Plantas , Óxido Nítrico/metabolismo , Dormência de Plantas/fisiologia , Germinação/fisiologia , Sementes/metabolismo , Reguladores de Crescimento de Plantas , Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
16.
Int J Mol Sci ; 23(6)2022 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-35328754

RESUMO

Global climate change is threatening wheat productivity; improved yield under drought conditions is urgent. Here, diverse spring-wheat lines (modern, old and wheat-rye introgressions) were examined in an image-based early-vigour assay and a controlled-conditions (Biotron) trial that evaluated 13 traits until maturity. Early root vigour was significantly higher in the old Swedish lines (root length 8.50 cm) and introgressed lines with 1R (11.78 cm) and 1RS (9.91 cm) than in the modern (4.20 cm) and 2R (4.67 cm) lines. No significant correlation was noted between early root and shoot vigour. A higher yield was obtained under early drought stress in the 3R genotypes than in the other genotype groups, while no clear patterns were noted under late drought. Evaluating the top 10% of genotypes in terms of the stress-tolerance index for yield showed that root biomass, grains and spikes per plant were accountable for tolerance to early drought, while 1000-grain weight and flag-leaf area were accountable for tolerance to late drought. Early root vigour was determined as an important focus trait of wheat breeding for tolerance to climate-change-induced drought. The responsible genes for the trait should be searched for in these diverse lines. Additional drought-tolerance traits determined here need further elaboration to identify the responsible genes.


Assuntos
Secas , Triticum , Mudança Climática , Fenótipo , Melhoramento Vegetal , Triticum/genética
17.
Plant Biotechnol J ; 19(1): 26-34, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32996672

RESUMO

Transgressive segregation and heterosis are the reasons that plant breeding works. Molecular explanations for both phenomena have been suggested and play a contributing role. However, it is often overlooked by molecular genetic researchers that transgressive segregation and heterosis are most simply explained by dispersion of favorable alleles. Therefore, advances in molecular biology will deliver the most impact on plant breeding when integrated with sources of heritable trait variation - and this will be best achieved within a quantitative genetics framework. An example of the power of quantitative approaches is the implementation of genomic selection, which has recently revolutionized animal breeding. Genomic selection is now being applied to both hybrid and inbred crops and is likely to be the major source of improvement in plant breeding practice over the next decade. Breeders' ability to efficiently apply genomic selection methodologies is due to recent technology advances in genotyping and sequencing. Furthermore, targeted integration of additional molecular data (such as gene expression, gene copy number and methylation status) into genomic prediction models may increase their performance. In this review, we discuss and contextualize a suite of established quantitative genetics themes relating to hybrid vigour, transgressive segregation and their central relevance to plant breeding, with the aim of informing crop researchers outside of the quantitative genetics discipline of their relevance and importance to crop improvement. Better understanding between molecular and quantitative disciplines will increase the potential for further improvements in plant breeding methodologies and so help underpin future food security.


Assuntos
Vigor Híbrido , Depressão por Endogamia , Melhoramento Vegetal , Produtos Agrícolas , Vigor Híbrido/genética , Endogamia , Fenótipo
18.
New Phytol ; 232(3): 1311-1322, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34314512

RESUMO

Temperature variation during seed set is an important modulator of seed dormancy and impacts the performance of crop seeds through effects on establishment rate. It remains unclear how changing temperature during maturation leads to dormancy and growth vigour differences in nondormant seedlings. Here we take advantage of the large seed size in Brassica oleracea to analyse effects of temperature on individual seed tissues. We show that warm temperature during seed maturation promotes seed germination, while removal of the endosperm from imbibed seeds abolishes temperature-driven effects on germination. We demonstrate that cool temperatures during early seed maturation lead to abscisic acid (ABA) retention specifically in the endosperm at desiccation. During this time temperature affects ABA dynamics in individual seed tissues and regulates ABA catabolism. We also show that warm-matured seeds preinduce a subset of germination-related programmes in the endosperm, whereas cold-matured seeds continue to store maturation-associated transcripts including DOG1 because of effects on mRNA degradation before quiescence, rather than because of the effect of temperature on transcription. We propose that effects of temperature on seed vigour are explained by endospermic ABA breakdown and the divergent relationships between temperature and mRNA breakdown and between temperature, seed moisture and the glass transition.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ácido Abscísico , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Endosperma/genética , Endosperma/metabolismo , Regulação da Expressão Gênica de Plantas , Germinação , Dormência de Plantas/genética , RNA Mensageiro/genética , Sementes/metabolismo , Temperatura
19.
J Exp Bot ; 72(7): 2312-2333, 2021 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-33512455

RESUMO

Germination performance is affected following seed exposure to a combination of temperature fluctuations and cycles of hydration and dehydration. This has long been exploited in a seed technology termed priming, which increases germination speed and seedling vigour, but these benefits have often been associated with effects on seed lifespan, or longevity, with conflicting evidence for positive and negative effects. Seed longevity is a key seed trait influencing not only the storage of commercial stocks but also in situ and ex situ seed conservation. In the context of increasingly variable environmental conditions faced by both crops and wild species, this has led to renewed interest in understanding the molecular factors that underlie priming. Here, we provide an overview of the literature relating to the effect of priming on seed lifespan, and catalogue the different parameters used for priming treatments and their consequences on longevity for a range of species. Our current limited understanding of the molecular basis for priming effects is also outlined, with an emphasis on recent advances and promising approaches that should lead towards the application and monitoring of the priming process in a less empirical manner.


Assuntos
Germinação , Longevidade , Plântula , Sementes
20.
Ann Bot ; 127(7): 931-941, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-33619533

RESUMO

BACKGROUND AND AIMS: Root sprouting (RS), i.e. the ability to form adventitious buds on roots, is an important form of clonal growth in a number of species, and serves as both a survival strategy and a means of spatial expansion, particularly in plants growing in severely and recurrently disturbed habitats. Occurrence and/or success of plants in severely and recurrently disturbed habitats are determined by two components, namely the ability to produce adventitious buds on roots and the vigour of their production. As mechanisms behind different magnitudes of RS remain unclear, our study investigates: (1) whether the presence or absence of specific tissues in roots can promote or limit RS; and (2) whether there is some relationship between RS ability, RS vigour and species niche. METHODS: We studied RS ability together with RS vigour in 182 Central European herbaceous species under controlled experimental conditions. We used phylogenetic logistic regressions to model the presence of RS, RS vigour, the relationship between RS and anatomical traits and the relationship between RS and parameters of species niches. KEY RESULTS: A quarter of herbs examined were able to produce adventitious buds on roots. They were characterized by their preference for open dry habitats, the presence of secondary root thickening and the occurrence of sclerified cortical cells in roots. Root sprouting vigour was not associated with any specific anatomical pattern, but was correlated with the environmental niches of different species, indicating that preferred disturbed and dry habitats might represent a selection pressure for more vigorous root sprouters than undisturbed and wet habitats. CONCLUSIONS: Our study shows that sprouting from roots is quite common in temperate dicotyledonous herbs. Two components of RS - ability and vigour - should be considered separately in future studies. We would also like to focus more attention on RS in herbs from other regions as well as on external forces and internal mechanisms regulating evolution and the functions of RS in both disturbed and undisturbed habitats.


Assuntos
Magnoliopsida , Raízes de Plantas , Ecossistema , Filogenia , Plantas
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