scholarly journals Somatic variants for seed and fruit set in grapevine

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Laura Costantini ◽  
Paula Moreno-Sanz ◽  
Chinedu Charles Nwafor ◽  
Silvia Lorenzi ◽  
Annarita Marrano ◽  
...  

Abstract Background Grapevine reproductive development has direct implications on yield. It also impacts on berry and wine quality by affecting traits like seedlessness, berry and bunch size, cluster compactness and berry skin to pulp ratio. Seasonal fluctuations in yield, fruit composition and wine attributes, which are largely driven by climatic factors, are major challenges for worldwide table grape and wine industry. Accordingly, a better understanding of reproductive processes such as gamete development, fertilization, seed and fruit set is of paramount relevance for managing yield and quality. With the aim of providing new insights into this field, we searched for clones with contrasting seed content in two germplasm collections. Results We identified eight variant pairs that seemingly differ only in seed-related characteristics while showing identical genotype when tested with the GrapeReSeq_Illumina_20K_SNP_chip and several microsatellites. We performed multi-year observations on seed and fruit set deriving from different pollination treatments, with special emphasis on the pair composed by Sangiovese and its seedless variant locally named Corinto Nero. The pollen of Corinto Nero failed to germinate in vitro and gave poor berry set when used to pollinate other varieties. Most berries from both open- and cross-pollinated Corinto Nero inflorescences did not contain seeds. The genetic analysis of seedlings derived from occasional Corinto Nero normal seeds revealed that the few Corinto Nero functional gametes are mostly unreduced. Moreover, three genotypes, including Sangiovese and Corinto Nero, were unexpectedly found to develop fruits without pollen contribution and occasionally showed normal-like seeds. Five missense single nucleotide polymorphisms were identified between Corinto Nero and Sangiovese from transcriptomic data. Conclusions Our observations allowed us to attribute a seedlessness type to some variants for which it was not documented in the literature. Interestingly, the VvAGL11 mutation responsible for Sultanina stenospermocarpy was also discovered in a seedless mutant of Gouais Blanc. We suggest that Corinto Nero parthenocarpy is driven by pollen and/or embryo sac defects, and both events likely arise from meiotic anomalies. The single nucleotide polymorphisms identified between Sangiovese and Corinto Nero are suitable for testing as traceability markers for propagated material and as functional candidates for the seedless phenotype.

2020 ◽  
Author(s):  
Laura Costantini ◽  
Paula Moreno-Sanz ◽  
Chinedu Charles Nwafor ◽  
Silvia Lorenzi ◽  
Annarita Marrano ◽  
...  

Abstract Background: Grapevine reproductive development has direct implications on yield. It also impacts on berry and wine quality by affecting traits like cluster compactness, bunch and berry size, berry skin to pulp ratio or seedlessness. Seasonal fluctuations in yield, fruit composition and wine attributes, which are largely driven by climatic factors, are major challenges for worldwide table grape and wine industry. Accordingly, a better understanding of reproductive processes such as gamete development, fertilization, seed and fruit set is of paramount relevance for managing yield and quality. With the aim of providing new insights into this field, we searched for clones with contrasting seed content in two germplasm collections. Results: We identified eight variant pairs that seemingly differ only in seed-related characteristics while showing identical genotype when tested with the GrapeReSeq_Illumina_20K_SNP_chip and several microsatellites. We performed multi-year observations on fruit and seed set deriving from different pollination treatments, with special emphasis on the pair composed by Sangiovese and its seedless variant locally named Corinto Nero. The pollen of Corinto Nero failed to germinate in vitro and gave poor berry set when used to pollinate other varieties. Most berries from both open- and cross-pollinated Corinto Nero inflorescences did not contain seeds. The genetic analysis of seedlings derived from occasional Corinto Nero normal seeds revealed that the few Corinto Nero functional gametes are mostly unreduced. A number of genes potentially involved in sporogenesis and gametogenesis showed contrasting expression between Corinto Nero and Sangiovese and five missense single nucleotide polymorphisms were identified from transcriptomic data. The above findings suggest that the seedless phenotype of Corinto Nero is driven by pollen and/or embryo sac defects, and both events likely arise from meiotic anomalies. Finally, three genotypes, including Sangiovese and Corinto Nero, were unexpectedly found to develop fruits without pollen contribution and occasionally showed normal-like seeds. Conclusions: Our collective results suggest that parthenocarpy and stenospermocarpy are not restricted to Black Corinth (alias Korinthiaki) and Sultanina-derived cultivars. The single nucleotide polymorphisms identified between Sangiovese and its parthenocarpic variant Corinto Nero are suitable for testing as traceability markers for propagated material and as functional candidates for the seedless phenotype.


2016 ◽  
Vol 141 (1) ◽  
pp. 62-65 ◽  
Author(s):  
Michael J. Havey ◽  
Yul-Kyun Ahn

Garlic (Allium sativum) is cultivated worldwide and appreciated for its culinary uses. In spite of primarily being asexually propagated, garlic shows great morphological variation and adaptability to diverse production environments. Molecular markers and phenotypic characteristics have been used to assess the genetic diversity among garlics. In this study, we undertook transcriptome sequencing from a single garlic plant to identify molecular markers in expressed regions of the garlic genome. Garlic sequences were assembled and selected if they were similar to monomorphic sequences from a doubled haploid (DH) of onion (Allium cepa). Single nucleotide polymorphisms (SNPs) and insertion–deletion (indel) events were identified in 4355 independent garlic assemblies. A sample of the indels was verified using the original complementary DNA (cDNA) library and genomics DNAs from diverse garlics, and segregations confirmed by sexual progenies of garlic. These molecular markers from the garlic transcriptome should be useful for estimates of genetic diversity, identification and removal of duplicate accessions from germplasm collections, and the development of a detailed genetic map of this important vegetable crop.


2008 ◽  
Vol 76 (5) ◽  
pp. 2227-2234 ◽  
Author(s):  
Debbie M. Hunt ◽  
José W. Saldanha ◽  
John F. Brennan ◽  
Pearline Benjamin ◽  
Molly Strom ◽  
...  

ABSTRACT Single nucleotide polymorphisms (SNPs) are present in the global transcriptional regulator cyclic AMP (cAMP) receptor protein (CRP) of the attenuated vaccine strain Mycobacterium bovis, bacillus Calmette-Guérin (BCG). We have found that these SNPs resulted in small but significant changes in the expression of a number of genes in M. tuberculosis when a deletion of the Rv3676 CRP was complemented by the BCG allele, compared to complementation by the M. tuberculosis allele. We can explain these changes in gene expression by modeling the structure of the mycobacterial protein on the known structure of CRP from Escherichia coli. Thus, the SNP change in the DNA-binding domain, Lys178, is predicted to form a hydrogen bond with the phosphate backbone of the DNA, as does the equivalent residue in E. coli, whereas Glu178 in M. tuberculosis/M. bovis does not, thus explaining the stronger binding reported for CRP of BCG to CRP-binding sites in mycobacterial DNA. In contrast, the SNP change in the nucleotide binding domain (Leu47Pro) is predicted to result in the loss of one hydrogen bond, which is accommodated by the structure, and would not therefore be expected to cause any change in function relating to cAMP binding. The BCG allele fully complemented the growth defect caused by the deletion of the Rv3676 protein in M. tuberculosis, both in vitro and in macrophage and mouse infections, suggesting that these SNPs do not play any role in the attenuation of BCG. However, they may have allowed BCG to grow better under the in vitro-selective conditions used in its derivation from the M. bovis wild type.


2012 ◽  
Vol 445 (1) ◽  
pp. 69-79 ◽  
Author(s):  
James Edwards ◽  
Diana Quinn ◽  
Karyn-Anne Rowbottom ◽  
Jean L. Whittingham ◽  
Melanie J. Thomson ◽  
...  

The closely related pathogenic Neisseria species N. meningitidis and N. gonorrhoeae are able to respire in the absence of oxygen, using nitrite as an alternative electron acceptor. aniA (copper-containing nitrite reductase) is tightly regulated by four transcriptional regulators: FNR (fumarate and nitrate reductase), NarP, FUR (Ferric uptake regulator) and NsrR. The four regulators control expression of aniA in N. meningitidis by binding to specific and distinct regions of the promoter. We show in the present study that FUR and NarP are both required for the induction of expression of aniA in N. meningitidis, and that they bind adjacent to one another in a non-co-operative manner. Activation via FUR/NarP is dependent on their topological arrangement relative to the RNA polymerase-binding site. Analysis of the sequence of the aniA promoters from multiple N. meningitidis and N. gonorrhoeae strains indicates that there are species-specific single nucleotide polymorphisms, in regions predicted to be important for regulator binding. These sequence differences alter both the in vitro DNA binding and the promoter activation in intact cells by key activators FNR (oxygen sensor) and NarP (which is activated by nitrite in N. meningitidis). The weak relative binding of FNR to the N. gonorrhoeae aniA promoter (compared to N. meningitidis) is compensated for by a higher affinity of the gonococcal aniA promoter for NarP. Despite containing nearly identical genes for catalysing and regulating denitrification, variations in the promoter for the aniA gene appear to have been selected to enable the two pathogens to tune differentially their responses to environmental variables during the aerobic–anaerobic switch.


2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Carlijn H. C. Litjens ◽  
Jeroen J. M. W van den Heuvel ◽  
Frans G. M. Russel ◽  
Rob E. Aarnoutse ◽  
Lindsey H. M. te Brake ◽  
...  

ABSTRACT Single nucleotide polymorphisms in the OATP1B1 transporter have been suggested to partially explain the large interindividual variation in rifampicin exposure. HEK293 cells overexpressing wild-type (WT) or OATP1B1 variants *1b, *4, *5, and *15 were used to determine the in vitro rifampicin intrinsic clearance. For OATP1B1*5 and *15, a 36% and 42% reduction in intrinsic clearance, respectively, compared to WT was found. We consider that these differences in intrinsic clearance most likely have minor clinical implications.


2013 ◽  
Vol 33 (12) ◽  
pp. 1391-1402 ◽  
Author(s):  
Fernanda S. Fortes ◽  
Marcelo B. Molento

A seleção e a crescente disseminação de nematoides resistentes aos anti-helmínticos mais comumente utilizados, benzimidazóis (BZs), imidazotiazóis e lactonas macrocíclicas (LMs), constituem um sério entrave na produção de pequenos ruminantes em todo o mundo. O uso de métodos eficientes e sensíveis para a detecção e o monitoramento da resistência anti-helmíntica no campo torna-se urgente, especialmente para os grupos de BZs e LMs, devido aos constantes relatos de resistência. A obtenção de um diagnóstico preciso e precoce da resistência é extremamente importante para auxiliar a tomada de decisão em programas de controle parasitário, com o objetivo de preservar a vida útil dos produtos e limitar o desenvolvimento da resistência nas populações de nematoides. Os testes in vivo e, mais recentemente, os testes in vitro têm sido desenvolvidos para a detecção de nematoides resistentes aos principais grupos de anti-helmínticos. No entanto, a disponibilidade de testes in vitro validados e o seu uso prático ainda são muito limitados. Embora o teste de redução na contagem de ovos nas fezes (TRCOF, in vivo - indireto) seja o principal método de escolha para a detecção de resistência no campo, vem recebendo críticas quanto à validade dos resultados, e passa por significativas modificações. Além disso, o desenvolvimento de técnicas moleculares a partir de alterações genômicas gerou avanços consideráveis nessa área de investigação, com o uso de mutações nos códons 167, 198 e 200 do gene da β-tubulina como principais SNPs (polimorfismos de nucleotídeo único; do inglês Single Nucleotide Polymorphisms) associados à resistência aos BZs. A presente revisão tem o objetivo de discutir os métodos de diagnóstico disponíveis para a detecção de resistência anti-helmíntica em nematoides de pequenos ruminantes, destacando progressos e obstáculos para seu uso na rotina laboratorial e no campo.


Sign in / Sign up

Export Citation Format

Share Document