Tomato CRABS CLAW paralogues interact with chromatin remodelling factors to mediate carpel development and floral determinacy

CRABS CLAW (CRC) orthologues play a crucial role in floral meristem (FM) determinacy and gynoecium formation across angiosperms, the key developmental processes for ensuring successful plant reproduction and crop production. However, the mechanisms behind CRC mediated FM termination are far from fully understood. Here, we addressed the functional characterization of tomato (Solanum lycopersicum) paralogous CRC genes. Using mapping-by-sequencing, RNA interference and CRISPR/Cas9 techniques, expression analyses, protein-protein interaction assays and Arabidopsis complementation experiments, we examined their potential roles in FM determinacy and carpel formation. We revealed that the incomplete penetrance and variable expressivity of the indeterminate carpel-inside-carpel phenotype observed in fruit iterative growth (fig) mutant plants are due to the lack of function of the S. lycopersicum CRC homologue SlCRCa. Furthermore, a detailed functional analysis of tomato CRC paralogues, SlCRCa and SlCRCb, allowed us to propose that they operate as positive regulators of FM determinacy by acting in a compensatory and partially redundant manner to safeguard the proper formation of flowers and fruits. Our results uncover for the first time the physical interaction of putative CRC orthologues with members of the chromatin remodelling complex that epigenetically represses WUSCHEL expression through histone deacetylation to ensure the proper termination of floral stem cell activity.Peer reviewe

Approaching the genetic dissection of indirect adventitious organogenesis process in tomato explants

[EN] The screening of 862 T-DNA lines was carried out to approach the genetic dissection of indirect adventitious organogenesis in tomato. Several mutants defective in different phases of adventitious organogenesis, namely callus growth (tdc-1), bud differentiation (tdb-1,-2,-3) and shoot-bud development (tds-1) were identified and characterized. The alteration of the TDC-1 gene blocked callus proliferation depending on the composition of growth regulators in the culture medium. Calli from tds-1 explants differentiated buds but did not develop normal shoots. Histological analysis showed that their abnormal development is due to failure in the organization of normal adventitious shoot meristems. Interestingly, tdc-1 and tds-1 mutant plants were indistinguishable from WT ones, indicating that the respective altered genes play specific roles in cell proliferation from explant cut zones (TDC-1 gene) or in the organization of adventitious shoot meristems (TDS-1 gene). Unlike the previous, plants of the three mutants defective in the differentiation of adventitious shoot-buds (tdb-1,-2,-3) showed multiple changes in vegetative and reproductive traits. Cosegregation analyses revealed the existence of an association between the phenotype of the tdb-3 mutant and a T-DNA insert, which led to the discovery that the SlMAPKKK17 gene is involved in the shoot-bud differentiation process.Vicente Moreno and Rafael Lozano thank the Ministry of Science and Innovation (State Innovation Agency) for granting the projects PID2019-110833RB-C32 and PID2019-110833RB-C31. Benito Pineda's work in the context of this article has been funded by 'Aid for First Research Projects (PAID-06-18)' by the Vicerrectorado de Investigacion, Innovacion y Transferencia de la Universitat Politecnica de Valencia (UPV), Valencia, Spain'. The PhD fellowship for Jorge Sanchez-Lopez and Marybel Jaquez-Gutierrez were funded by the Universidad de Sinaloa and the CONACYT of Mexico.Sanchez-Lopez, J.; Atarés Huerta, A.; Jaquez-Gutierrez, M.; Ortiz-Atienza, A.; Capel, C.; Pineda Chaza, BJ.; García Sogo, B.... (2021). Approaching the genetic dissection of indirect adventitious organogenesis process in tomato explants. Plant Science. 302:1-14. https://doi.org/10.1016/j.plantsci.2020.110721S11430

The SlCBL10 calcineurin B-like protein ensures plant growth under salt stress by regulating Na+ and Ca2+ homeostasis

[EN] Characterization of a new tomato (Solanum lycopersicum) T-DNA mutant allowed for the isolation of the CALCINEURIN B-LIKE PROTEIN 10 (SlCBL10) gene whose lack of function was responsible for the severe alterations observed in the shoot apex and reproductive organs under salinity conditions. Physiological studies proved that SlCBL10 gene is required to maintain a proper low Na+/Ca2+ ratio in growing tissues allowing tomato growth under salt stress. Expression analysis of the main responsible genes for Na+ compartmentalization (i.e. Na+/H+ EXCHANGERs, SALT OVERLY SENSITIVE, HIGH-AFFINITY K+ TRANSPORTER 1; 2, H+-pyrophosphatase AVP1 [SlAVP1] and V-ATPase [SlVHA-A1]) supported a reduced capacity to accumulate Na+ in Slcbl10 mutant leaves, which resulted in a lower uploading of Na+ from xylem, allowing the toxic ion to reach apex and flowers. Likewise, the tomato CATION EXCHANGER 1 and TWO-PORE CHANNEL 1 (SlTPC1), key genes for Ca2+ fluxes to the vacuole, showed abnormal expression in Slcbl10 plants indicating an impaired Ca2+ release from vacuole. Additionally, complementation assay revealed that SlCBL10 is a true ortholog of the Arabidopsis (Arabidopsis thaliana) CBL10 gene, supporting that the essential function of CBL10 is conserved in Arabidopsis and tomato. Together, the findings obtained in this study provide new insights into the function of SlCBL10 in salt stress tolerance. Thus, it is proposed that SlCBL10 mediates salt tolerance by regulating Na+ and Ca2+ fluxes in the vacuole, cooperating with the vacuolar cation channel SlTPC1 and the two vacuolar H+-pumps, SlAVP1 and SlVHA-A1, which in turn are revealed as potential targets of SlCBL10.This study was supported by grants from the Plant KBBE Program (EUI2009-04074), the Spanish Ministerio de Economia y Competitividad (AGL2012-40150, AGL2015-64991-C3-1-R/2-R/3-R, and BIO2016-79187-R), as well as the French National Research Agency ENDOREPIGEN project. A.O.-A. was supported by a PhD fellowship from the Ministerio de Economia y Competitividad (BIO2009-11484).Egea, I.; Pineda Chaza, BJ.; Ortiz Atienza, A.; Plasencia, F.; Drevensek, S.; García Sogo, B.; Yuste-Lisbona, FJ.... (2018). The SlCBL10 calcineurin B-like protein ensures plant growth under salt stress by regulating Na+ and Ca2+ homeostasis. PLANT PHYSIOLOGY. 176(2):1676-1693. https://doi.org/10.1104/pp.17.01605S16761693176

The European Reference Genome Atlas: piloting a decentralised approach to equitable biodiversity genomics.

ABSTRACT: A global genome database of all of Earth’s species diversity could be a treasure trove of scientific discoveries. However, regardless of the major advances in genome sequencing technologies, only a tiny fraction of species have genomic information available. To contribute to a more complete planetary genomic database, scientists and institutions across the world have united under the Earth BioGenome Project (EBP), which plans to sequence and assemble high-quality reference genomes for all ∼1.5 million recognized eukaryotic species through a stepwise phased approach. As the initiative transitions into Phase II, where 150,000 species are to be sequenced in just four years, worldwide participation in the project will be fundamental to success. As the European node of the EBP, the European Reference Genome Atlas (ERGA) seeks to implement a new decentralised, accessible, equitable and inclusive model for producing high-quality reference genomes, which will inform EBP as it scales. To embark on this mission, ERGA launched a Pilot Project to establish a network across Europe to develop and test the first infrastructure of its kind for the coordinated and distributed reference genome production on 98 European eukaryotic species from sample providers across 33 European countries. Here we outline the process and challenges faced during the development of a pilot infrastructure for the production of reference genome resources, and explore the effectiveness of this approach in terms of high-quality reference genome production, considering also equity and inclusion. The outcomes and lessons learned during this pilot provide a solid foundation for ERGA while offering key learnings to other transnational and national genomic resource projects.info:eu-repo/semantics/publishedVersio

I Jornada de Aulas Abiertas: Encuentro de Docentes de la Facultad de Ciencias Económicas

La Jornada de Aulas Abiertas quiere ser una oportunidad para que los docentes de la Facultad de Ciencias Económicas nos encontremos en un espacio de reflexión y revisión de nuestras prácticas, distendido, cálido y respetuoso, que nos permita compartir nuestras experiencias cotidianas en las aulas, tanto presenciales como virtuales. Es la posibilidad de conocernos, intercambiar, aprender y contagiarnos de las inquietudes y el entusiasmo que muchos docentes ponen en juego cotidianamente. En el marco de propuestas de enseñanza, se analizaron recursos multimediales, materiales de estudio, aulas virtuales, redes sociales, aplicaciones web, juegos y actividades de evaluación y coevaluación originales; también se abordaron problemáticas y propuestas para favorecer vinculaciones con la práctica profesional. Estas fueron algunas de las cuestiones abordadas y compartidas en las presentaciones de nuestros colegas. Distintas propuestas, pero siempre con el propósito de favorecer las oportunidades de aprendizaje de nuestros estudiantes. Esta publicación pretende ampliar el alcance de esta actividad. Es una invitación para que los y las docentes que participaron puedan revisar nuevamente aquellas actividades que les parecieron valiosas, o las que no pudieron presenciar. Y para aquellos/as que no tuvieron la posibilidad de estar presentes, puedan descubrir cuánto podemos hacer para que nuestros estudiantes aprendan más y mejor, y se animen a iniciar sus propios recorridos. Esperamos repetir este evento para seguir aprendiendo de las iniciativas de los/las docentes de nuestra Facultad, poder hablar de lo que nos preocupa y nos enorgullece, en particular de las propuestas que desarrollamos en el aula para favorecer la comprensión, promover el entusiasmo, abordar temas complejos y errores frecuentes de nuestros estudiantes. Desde el Área de Formación Docente y Producción Educativa queremos agradecer a las autoridades de nuestra Facultad por acompañarnos en este desafío y a los/las docentes que estuvieron presentes compartiendo sus experiencias.Fil: Sabulsky, Gabriela. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Margaría, Oscar A. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Iturralde, Ivan. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Domenech, Roberto. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Torrico, Julieta. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Estigarribia, Lucrecia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Gohlke, Guillermo. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Rosenfeld, Valeria. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Montenjano, Franco. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Atienza, Bárbara. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Becerra, Natalia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Alonso, Micaela. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Tomatis, Karina. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Saunders, Shirley. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: David, María Laura. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Flores, Verónica Andrea. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Heckmann, Gerardo. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Vega, Juan José. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Trucchi, Carlos. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Ferro, Flavia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Díaz, Cecilia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Peretto, Claudia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Racagni, Josefina. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Guardiola, Mariana. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: López, Sonia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Beltrán, Natacha. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Russo, Paulo. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Sánchez, Pablo. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Rocha Vargas, Marcelo. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Flores, Norma. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Arévalo, Eliana. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Pacheco, Verónica. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Delmonte, Laura. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Stanecka, Nancy. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Caminos, Ana Belén. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Ahumada, María Inés. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Caro, Norma Patricia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Bravino, Laura. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Giménez, Siria Miriam. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Perona, Eugenia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Cuttica, Mariela. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: García, Gladys Susana. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Cohen, Natalia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Tapia, Sebastián. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Erazu, Damián. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Torres, César. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Casini, Rosanna Beatriz. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Rosales, Julio. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Infante, Roberto Adrián. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Ricci, María Beatriz. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Römer, Gabriela. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Goyeneche, Noel. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Marzo, Emanuel. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Olmos, Mariano. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Bottino, Cecilia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Cacciagiú, Victor. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Scidá, María Florencia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Guajardo Molina, Vanesa. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Batistella, Silvana del V. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Huanchicay, Silvia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Jones, Carola. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Cassutti, Marcela Beatriz. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Sánchez, Juan Nicolás. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Arónica, Sandra. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Ortega, Fernando. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Peretti, Florencia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Tagle, María Mercedes. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Asís, Gloria Susana. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Ortiz Figueroa, Ana María. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Giménez, Miriam Mónica. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Magnano, Cecilia. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Arias, Verónica. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina

Genetic interactions of the unfinished flower development (ufd) mutant support a significant role of the tomato UFD gene in regulating floral organogenesis

Tomato (Solanum lycopersicum L.) is a major vegetable crop that also constitutes a model species for the study of plant developmental processes. To gain insight into the control of flowering and floral development, a novel tomato mutant, unfinished flower development (ufd), whose inflorescence and flowers were unable to complete their normal development was characterized using double mutant and gene expression analyses. Genetic interactions of ufd with mutations affecting inflorescence fate (uniflora, jointless and single flower truss) were additive and resulted in double mutants displaying the inflorescence structure of the non-ufd parental mutant and the flower phenotype of the ufd mutant. In addition, ufd mutation promotes an earlier inflorescence meristem termination. Taken together, both results indicated that UFD is not involved in the maintenance of inflorescence meristem identity, although it could participate in the regulatory system that modulates the rate of meristem maturation. Regarding the floral meristem identity, the falsiflora mutation was epistatic to the ufd mutation even though FALSIFLORA was upregulated in ufd inflorescences. In terms of floral organ identity, the ufd mutation was epistatic to macrocalyx, and MACROCALYX expression was differently regulated depending on the inflorescence developmental stage. These results suggest that the UFD gene may play a pivotal role between the genes required for flowering initiation and inflorescence development (such as UNIFLORA, FALSIFLORA, JOINTLESS and SINGLE FLOWER TRUSS) and those required for further floral organ development such as the floral organ identity genes

Decoding Gene Expression Signatures Underlying Vegetative to Inflorescence Meristem Transition in the Common Bean

The tropical common bean (Phaseolus vulgaris L.) is an obligatory short-day plant that requires relaxation of the photoperiod to induce flowering. Similar to other crops, photoperiod-induced floral initiation depends on the differentiation and maintenance of meristems. In this study, the global changes in transcript expression profiles were analyzed in two meristematic tissues corresponding to the vegetative and inflorescence meristems of two genotypes with different sensitivities to photoperiods. A total of 3396 differentially expressed genes (DEGs) were identified, and 1271 and 1533 were found to be up-regulated and down-regulated, respectively, whereas 592 genes showed discordant expression patterns between both genotypes. Arabidopsis homologues of DEGs were identified, and most of them were not previously involved in Arabidopsis floral transition, suggesting an evolutionary divergence of the transcriptional regulatory networks of the flowering process of both species. However, some genes belonging to the photoperiod and flower development pathways with evolutionarily conserved transcriptional profiles have been found. In addition, the flower meristem identity genes APETALA1 and LEAFY, as well as CONSTANS-LIKE 5, were identified as markers to distinguish between the vegetative and reproductive stages. Our data also indicated that the down-regulation of the photoperiodic genes seems to be directly associated with promoting floral transition under inductive short-day lengths. These findings provide valuable insight into the molecular factors that underlie meristematic development and contribute to understanding the photoperiod adaptation in the common bean.This research was financially supported by PDI2020-114115RB-100/GO PROTEINLEG (GAIN 2021–2023) funded by MCIN/AEI/10.13039/501100011033 and MAPA, as appropriate, by ‘ERDF A way of making Europe’, by the ‘European Union’ or by the ‘European Union NextGenera-tionEU/PRTR’.Peer reviewe

A Tomato EMS-Mutagenized Population Provides New Valuable Resources for Gene Discovery and Breeding of Developmental Traits

Tomato (Solanum lycopersicum L.) is a major horticultural crop and a model species among eudicots, especially for traits related to reproductive development. Although considerable progress has been made since the tomato genome sequence project was completed, most of the genes identified remain predictions with an unknown or hypothetical function. This lack of functional characterization hampers the use of the huge amount of genomic information available to improve the quality and productivity of this crop. Reverse genetics strategies such as artificial mutagenesis and next-generation sequencing approaches build the perfect tandem for increasing knowledge on functional annotation of tomato genes. This work reports the phenotypic characterization of a tomato mutant collection generated from an EMS chemical mutagenesis program aimed to identify interesting agronomic mutants and novel gene functions. Tomato mutants were grouped into fourteen phenotypic classes, including vegetative and reproductive development traits, and the inheritance pattern of the identified mutations was studied. In addition, causal mutation of a selected mutant line was isolated through a mapping-by-sequencing approach as a proof of concept of this strategy’s successful implementation. Results support tomato mutagenesis as an essential tool for functional genomics in this fleshy-fruited model species and a highly valuable resource for future breeding programs of this crop species aimed at the development of more productive and resilient new varieties under challenging climatic and production scenarios

Vascular endothelial growth factor haplotypes are associated with severe ischaemic complications in giant cell arteritis regardless of the disease phenotype.

To determine whether functional vascular endothelial growth factor (VEGF) polymorphisms influence the expression of the clinical phenotype of giant cell arteritis (GCA). We also evaluated whether VEGF polymorphism is associated with the development of severe ischaemic manifestations in patients with GCA regardless of the clinical phenotype, classic cranial GCA or predominantly extracranial GCA large vessel vasculitis (LVV). VEGF rs833061 T/C, rs2010963 G/C and rs3025039 C/T polymorphisms were genotyped in 185 patients with biopsy-proven cranial GCA, 105 with extracranial LVV-GCA and 490 healthy controls. Allelic combinations (haplotypes) of VEGF were carried out. Comparisons were performed between patients with GCA and healthy controls as well as between patients with GCA stratified according to the clinical phenotype and the presence of severe ischaemic manifestations. No significant differences in genotype, allele, and haplotype frequencies of VEGF were found between patients with GCA and healthy controls as well as between GCA patients with the classic cranial pattern and the extracranial LVV-GCA pattern of the disease. However, the VEGF CGC haplotype (OR= 1.63 [1.05-2.53]) and the CGT haplotype (OR= 2.55 [1.10-5.91]) were significantly more frequent in GCA patients with severe ischaemic complications compared to those patients without these complications. VEGF haplotypes seem to play a role in the development of severe ischaemic manifestations in GCA patients, regardless of the clinical phenotype of expression of the disease

Considerations and consequences of allowing DNA sequence data as types of fungal taxa

Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.Peer reviewe