Publications by authors named "Pablo M Figueroa"

6 Publications

  • Page 1 of 1

Structural analysis of the woodland strawberry COI1-JAZ1 co-receptor for the plant hormone jasmonoyl-isoleucine.

J Mol Graph Model 2018 10 12;85:250-261. Epub 2018 Sep 12.

Phytohormone Research Laboratory, Institute of Biological Sciences, Universidad de Talca, Talca, Chile. Electronic address:

The phytohormone jasmonoyl-isoleucine (JA-Ile) regulates fundamental plant processes. Fragaria vesca, the woodland strawberry, is a model plant for the Rosaceae family, in which the JA-Ile perception is poorly understood at the molecular level. JA-Ile promotes binding of JAZ repressor to COI1 protein in Arabidopsis to activate jasmonate (JA)-dependent responses. The aim of this work was to understand the molecular basis of the interaction between the F. vesca COI1 (FvCOI1) and JAZ1 (FvJAZ1) promoted by JA-Ile using a computational approach. Multiple sequence alignments and phylogenetic analyses of amino acid sequences were performed for FvCOI1, FvJAZ1 and their ortholog sequences. 3D structures for FvCOI1 and FvJAZ1 proteins were built by methods of homology modeling, using AtCOI1-JA-Ile-AtJAZ1 as template and then they were further refined and validated by molecular dynamics (MD) simulation. A molecular docking approach along with MDS analysis were used to gain insights into the interaction between a putative degron-like sequence present in FvJAZ1 with the FvCOI1-JA-Ile complex. FvCOI1 and FvJAZ1 showed high and moderate sequence identity, respectively, with the corresponding ortholog proteins from other plant species including apple, grape, tomato and Arabidopsis. Moreover, the FvJAZ1 has a variant C-terminal IPMQRK sequence instead of the canonical LPIARR degron sequence located in the Jas domain of AtJAZ1. The MD simulation results showed that the FvCOI1-JA-Ile-FvJAZ1 complex was stable, and the IPMQRK peptide of FvJAZ1 directly interacted with FvCOI1 and JA-Ile. The present research provides novel insight into the molecular interactions among key JA-signaling components in the model plant F. vesca, being few examples of characterized JA-Ile receptors at a structural level in plants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jmgm.2018.09.004DOI Listing
October 2018

Application of a JA-Ile Biosynthesis Inhibitor to Methyl Jasmonate-Treated Strawberry Fruit Induces Upregulation of Specific MBW Complex-Related Genes and Accumulation of Proanthocyanidins.

Molecules 2018 06 13;23(6). Epub 2018 Jun 13.

Phytohormone Research Laboratory, Institute of Biological Sciences, Universidad de Talca, Talca 3465548, Chile.

Fleshy fruits are an important source of anthocyanins and proanthocyanidins (PAs), which protect plants against stress, and their consumption provides beneficial effects for human health. In strawberry fruit, the application of exogenous methyl jasmonate (MeJA) upregulates anthocyanin accumulation, although the relationship between the jasmonate pathway and anthocyanin and PA biosynthesis in fruits remains to be understood. Anthocyanin and PA accumulation is mainly regulated at the transcriptional level through R2R3-MYB and bHLH transcription factors in different plant species and organs. Here, the effect of jarin-1, a specific inhibitor of bioactive JA (jasmonoyl-isoleucine, JA-Ile) biosynthesis, on anthocyanin and PA accumulation was evaluated during strawberry ( × ) fruit development using an in vitro ripening system for 48 h. Also, we observed the effects of MeJA and the application of jarin-1 to MeJA-treated fruits (MeJA + jarin-1 treatment). We assessed changes of expression levels for the JA-Ile and MeJA biosynthetic ( and ), JA signaling-related ( and ), MYB-bHLH-WD40 (MBW) complex-related (, , and repressor ), and anthocyanin and PA biosynthetic , , , and ) genes. In addition, the promoter region of MBW complex-related genes was isolated and sequenced. We found a higher redness of strawberry fruit skin and anthocyanin content in MeJA-treated fruits with respect to jarin-1-treated ones concomitant with an upregulation of and genes. Inversely, the PA content was higher in jarin-1- and MeJA + jarin-1-treated than in MeJA-treated fruits. MeJA + jarin-1 treatment resulted in an upregulation of and associated transcription factors such as and along with and . Finally, we found JA-responsive elements in the promoter regions of genes. It is proposed that PA biosynthesis-related genes can be upregulated by the application of jarin-1 to MeJA-treated fruit, thus increasing PA accumulation in strawberry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules23061433DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6100305PMC
June 2018

Jasmonate signalling pathway in strawberry: Genome-wide identification, molecular characterization and expression of JAZs and MYCs during fruit development and ripening.

PLoS One 2018 10;13(5):e0197118. Epub 2018 May 10.

Phytohormone Research Laboratory, Institute of Biological Sciences, Universidad de Talca, Talca, Chile.

Jasmonates (JAs) are signalling molecules involved in stress responses, development and secondary metabolism biosynthesis, although their roles in fleshy-fruit development and ripening processes are not well known. In strawberry fruit, it has been proposed that JAs could regulate the early development through the activation of the JAs biosynthesis. Moreover, it has been reported that JA treatment increases anthocyanin content in strawberry fruit involving the bioactive jasmonate biosynthesis. Nevertheless, JA signalling pathway, of which main components are the COI1-JAZ co-receptor and the MYC transcription factors (TFs), has not been characterized in strawberry until now. Here we identified and characterized the woodland strawberry (Fragaria vesca) JAZ and MYC genes as well as studied their expression during development and ripening stages in commercial strawberry (Fragaria × ananassa) fruit. We described twelve putative JAZ proteins and two MYC TFs, which showed high conservation with respect to their orthologs in Arabidopsis thaliana and in other fleshy-fruit species such as Malus × domestica, Vitis vinifera and Solanum lycopersicum as revealed by gene synteny and phylogenetic analyses. Noteworthy, their expression levels exhibited a significant decrease from fruit development to ripening stages in F. × ananassa, along with others of the JA signalling-related genes such as FaNINJA and FaJAMs, encoding for negative regulators of JA responses. Moreover, we found that main JA signalling-related genes such as FaMYC2, and FaJAZ1 are promptly induced by JA treatment at early times in F. × ananassa fruit. These results suggest the conservation of the canonical JA signalling pathway in strawberry and a possible role of this pathway in early strawberry fruit development, which also correlates negatively with the beginning of the ripening process.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0197118PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5944998PMC
July 2018

Independent Preharvest Applications of Methyl Jasmonate and Chitosan Elicit Differential Upregulation of Defense-Related Genes with Reduced Incidence of Gray Mold Decay during Postharvest Storage of Fragaria chiloensis Fruit.

Int J Mol Sci 2017 Jul 3;18(7). Epub 2017 Jul 3.

Phytohormone Research Laboratory, Institute of Biological Sciences, University of Talca, Talca 3465548, Chile.

The Chilean strawberry () fruit has interesting organoleptic properties, but its postharvest life is affected by gray mold decay caused by . The effect of preharvest applications of methyl jasmonate (MeJA) or chitosan on the molecular defense-related responses and protection against gray mold decay were investigated in Chilean strawberry fruit during postharvest storage. Specifically, we inoculated harvested fruit with spores and studied the expression of genes encoding for the pathogenesis-related (PR) proteins β-1,3-glucanases (, and ) and chitinases ( and ), and for polygalacturonase inhibiting proteins ( and ) at 0, 2, 24, 48, and 72 h post inoculation (hpi). Remarkably, MeJA- and chitosan-treated fruit exhibited a lower incidence of infection than the control-treated at 48 and 72 hpi. At the molecular level, both are efficient elicitors for priming in fruit since we observed an upregulation of the , , and at 0 hpi. Moreover, a chitosan-mediated upregulation of s at early times post inoculation (2-24 hpi) and MeJA upregulated s (24-72 hpi) and at later times could contribute to reduce incidence by differential upregulation of defense genes. We concluded that preharvest applications of MeJA or chitosan had a long-lasting effect on the reduction of incidence during postharvest as well as an enhancer effect on the induction of and gene expression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms18071420DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5535912PMC
July 2017

Salt stress response triggers activation of the jasmonate signaling pathway leading to inhibition of cell elongation in Arabidopsis primary root.

J Exp Bot 2016 07 23;67(14):4209-20. Epub 2016 May 23.

Instituto de Ciencias Biológicas, Universidad de Talca, Talca 3465548, Chile

Salinity is a severe abiotic stress that affects irrigated croplands. Jasmonate (JA) is an essential hormone involved in plant defense against herbivory and in responses to abiotic stress. However, the relationship between the salt stress response and the JA pathway in Arabidopsis thaliana is not well understood at molecular and cellular levels. In this work we investigated the activation of JA signaling by NaCl and its effect on primary root growth. We found that JA-responsive JAZ genes were up-regulated by salt stress in a COI1-dependent manner in the roots. Using a JA-Ile sensor we demonstrated that activation of JA signaling by salt stress occurs in the meristematic zone and stele of the differentiation zone and that this activation was dependent on JAR1 and proteasome functions. Another finding is that the elongation zone (EZ) and its cortical cells were significantly longer in JA-related mutants (AOS, COI1, JAZ3 and MYC2/3/4 genes) compared with wild-type plants under salt stress, revealing the participation of the canonical JA signaling pathway. Noteworthy, osmotic stress - a component of salt stress - inhibited cell elongation in the EZ in a COI1-dependent manner. We propose that salt stress triggers activation of the JA signaling pathway followed by inhibition of cell elongation in the EZ. We have shown that salt-inhibited root growth partially involves the jasmonate signaling pathway in Arabidopsis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/jxb/erw202DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5301928PMC
July 2016
-->