Irene Villalta - Academia.edu (original) (raw)

Papers by Irene Villalta

Plant Physiology, Oct 16, 2015

Theoretical and Applied Genetics, Oct 10, 2008

Poster presentado en el 17th International Workshop on Plant Membrane Biology June 5-10, 2016 Ann... more Poster presentado en el 17th International Workshop on Plant Membrane Biology June 5-10, 2016 Annapolis (Maryland), USA

ABSTRACTThe precise timing of flowering in adverse environments is critical for plants to secure ... more ABSTRACTThe precise timing of flowering in adverse environments is critical for plants to secure reproductive success. We report a novel mechanism controlling the time of flowering by which the palmitoylation-dependent nuclear import of protein SOS3/CBL4, a Ca2+-signaling intermediary in the plant response to salinity, results in the selective stabilization of the flowering time regulator GIGANTEA inside the nucleus under salt stress, while degradation of GIGANTEA in the cytosol releases the protein kinase SOS2 to achieve salt tolerance. S-acylation of SOS3 was critical for its nuclear localization and the promotion of flowering, but dispensable for salt tolerance. SOS3 interacted with the photoperiodic flowering components GIGANTEA and FKF1 on the CONSTANS gene promoter to sustain the transcription of CO and FT under salinity. Thus, SOS3 acts as a Ca2+- and palmitoylation-dependent molecular switch that fine-tunes flowering in a saline environment through the shared spatial separat...

Journal of Animal Ecology

Plant Physiology

Rice (Oryza sativa) stands among the world's most important crop species. Rice is salt sensitive,... more Rice (Oryza sativa) stands among the world's most important crop species. Rice is salt sensitive, and the undue accumulation of sodium ions (Na +) in shoots has the strongest negative correlation with rice productivity under long-term salinity. The plasma membrane Na + /H + exchanger protein Salt Overly Sensitive 1 (SOS1) is the sole Na + efflux transporter that has been genetically characterized to date. Here, the importance of SOS1-facilitated Na + flux in the salt tolerance of rice was analyzed in a reversegenetics approach. A sos1 loss-of-function mutant displayed exceptional salt sensitivity that was correlated with excessive Na + intake and impaired Na + loading into the xylem, thus indicating that SOS1 controls net root Na + uptake and long-distance Na + transport to shoots. The acute Na + sensitivity of sos1 plants at low NaCl concentrations allowed analysis of the transcriptional response to sodicity stress without effects of the osmotic stress intrinsic to high-salinity treatments. In contrast with that in the wild type, sos1 mutant roots displayed preferential down-regulation of stress-related genes in response to salt treatment, despite the greater intensity of stress experienced by the mutant. These results suggest there is impaired stress detection or an inability to mount a comprehensive response to salinity in sos1. In summary, the plasma membrane Na + /H + exchanger SOS1 plays a major role in the salt tolerance of rice by controlling Na + homeostasis and possibly contributing to the sensing of sodicity stress.

Journal of chemical ecology, 2018

Ant queen pheromones (QPs) have long been known to affect colony functioning. In many species, QP... more Ant queen pheromones (QPs) have long been known to affect colony functioning. In many species, QPs affect important reproductive functions such as diploid larvae sexualization and egg-laying by workers, unmated queens (gynes), or other queens. Until the 1990s, these effects were generally viewed to be the result of queen manipulation through the use of coercive or dishonest signals. However, in their seminal 1993 paper, Keller and Nonacs challenged this idea, suggesting that QPs had evolved as honest signals that informed workers and other colony members of the queen's presence and reproductive state. This paper has greatly influenced the study of ant QPs and inspired numerous attempts to identify fertility-related compounds and test their physiological and behavioral effects. In the present article, we review the literature on ant QPs in various contexts and pay special attention to the role of cuticular hydrocarbons (CHCs). Although the controversy generated by Keller and Nona...

Plant physiology, Jan 11, 2018

KEA4, KEA5, and KEA6 are members of the Arabidopsis thaliana K+ efflux antiporter (KEA) family th... more KEA4, KEA5, and KEA6 are members of the Arabidopsis thaliana K+ efflux antiporter (KEA) family that share high sequence similarity, but whose function remains unknown. Here, we show their gene expression pattern, subcellular localization, and physiological function in Arabidopsis. KEA4, KEA5, and KEA6 had a similar tissue expression pattern and the three KEA proteins localized to the Golgi, the trans-Golgi network (TGN), and the pre-vacuolar compartment (PVC)/multivesicular bodies (MVB), suggesting overlapping roles of these proteins in the endomembrane system. Phenotypic analyses of single, double, and triple mutants confirmed functional redundancy. The triple mutant kea4 kea5 kea6 had small rosettes, short seedlings, and was sensitive to low K+ availability and to the sodicity imposed by high salinity. Also, the kea4 kea5 kea6 mutant plants had a reduced luminal pH in the Golgi, TGN, PVC, and vacuole, in accordance with the K/H exchange activity of KEA proteins. Genetic analysis i...

Molecular phylogenetics and evolution, 2018

The creation of geographic barriers has long been suspected to contribute to the formation of new... more The creation of geographic barriers has long been suspected to contribute to the formation of new species. We investigated the phylogeography of desert ants in the western Mediterranean basin in order to elucidate their mode of diversification. These insects which have a low dispersal capacity are recently becoming important model systems in evolutionary studies. We conducted an extensive sampling of species belonging to the Cataglyphis albicans group in the Iberian Peninsula (IP) and the northern Morocco (North Africa; NA). We then combined genetic, chemical and morphological analyses. The results suggest the existence of at least three and five clades in the IP and NA, respectively, whose delineation partially encompass current taxonomic classification. The three Iberian clades are monophyletic, but their origin in NA is uncertain (79% and 22% for Bayesian and Maximum Likelihood support, respectively). The estimation of divergence time suggests that a speciation process was initia...

Behavioral Ecology and Sociobiology, 2016

Consistent individual differences in personality traits should be favoured when those traits cont... more Consistent individual differences in personality traits should be favoured when those traits contribute to consistent individual fitness differences. However, how variations in behaviours are related to productivity remains scarcely explored in social species, particularly in insects. Here, we investigated whether exploratory, boldness and brood rescue behaviours expressed at the colony-level are associated with group productivity that is, colony growth, queen and worker production, and larvae survival in the gypsy ant Aphaenogaster senilis. We found that group-level exploratory activity, boldness, and brood rescue efficiency were highly correlated. Furthermore, both exploratory activity and brood rescue efficiency were significantly consistent across 11 weeks. Finally, differences in brood rescue efficiency correlated positively with colony growth, queen and worker production, and larvae survival. These results show that colony-level personality may be linked with differences in colony life-history strategy, which may promote the emergence and maintenance of personality traits in group-living species.

Ecological Entomology, 2016

The Science of Nature, 2016

Behavioral Ecology and Sociobiology, 2015

Plant physiology, Jan 16, 2015

Plant growth and development requires efficient acquisition of essential elements. Potassium (K+)... more Plant growth and development requires efficient acquisition of essential elements. Potassium (K+) is an important macronutrient present in the soil solution at a wide range of concentrations. Regulation of the K+ uptake systems in the roots is essential to secure K+ supply. It has been shown in Arabidopsis that when the external K+ concentration is very low (<10 µM), K+ nutrition depends exclusively on the high-affinity K+ transporter HAK5. Low-K+ induced transcriptional activation of the gene encoding HAK5 has been previously reported. Here we show the posttranscriptional regulation for HAK5 transport activity by phosphorylation. Expression in a heterologous system showed that the Ca2+ sensors CBL1, CBL8, CBL9 and CBL10, together with CBL-interacting kinase CIPK23 activated HAK5 in vivo. This activation produced an increase in the affinity and the Vmax of K+ transport. In vitro experiments show that the N-terminus of HAK5 is phosphorylated by CIPK23. This supports the idea that ...

Theoretical and Applied Genetics

The rootstock effect on the fruit yield of a grafted tomato variety was genetically analyzed unde... more The rootstock effect on the fruit yield of a grafted tomato variety was genetically analyzed under salinity using as rootstock two populations of F(9) lines developed from a salt sensitive genotype of Solanum lycopersicum var. cerasiforme, as female parent, and two salt tolerant lines, as male parents, from S. pimpinellifolium, the P population (123 lines), and S. cheesmaniae, the C population (100 lines). There were rootstock lines from the two populations (up to 65% in the P population) that raised the fruit yield of the commercial hybrid under saline conditions. It is shown that this salt tolerance rootstock effect is a heritable trait (h (2) near 0.3), governed by at least eight QTLs. The most relevant component was the number of fruits. Thus most detected QTLs correspond to this component. In general, QTL gene effects are medium-sized, with contributions from 8.5 up to 15.9% at most, and the advantageous allele comes from the wild, salt tolerant species. Only two fruit yield QT...

Molecular Techniques in Crop Improvement, 2009

To maintain the quality of life on earth, agriculture has to colonize marginal areas and decrease... more To maintain the quality of life on earth, agriculture has to colonize marginal areas and decrease its dependence on pesticides, herbicides, fertilizers and water. Plant breeding should integrate the latest innovations in biology and genetics to better face this challenge. Quantitative trait loci (QTL) analysis allows the location and effect-estimation of the genetic elements controlling any trait by the joint study of segregation of marker genotypes and of phenotypic values of individuals or lines. QTL analysis is now seen as a procedure to fill the gap between "omics" and the field. This chapter is focused on recent advances of three applications of QTL analysis in plants: (1) the genetic integration of agronomical, physiological and gene expression related traits (the scientific value of QTL analysis); (2) Marker-assisted selection (MAS) in breeding programs and (3) the utilization of wild germplasm to improve quantitative traits with breeding tomato for salt tolerance as an example.

Theoretical and Applied Genetics, 2005