Carlos Gaete-Eastman

Universidad de Talca · Institute of Plan Biology and Biotechnology (IBVB)

Quantitative real-time PCR (RT-qPCR) is used extensively in gene expression studies. For adequate comparisons, the identification and use of reliable reference genes are crucial. Nevertheless, the availability of such genes in strawberry species is limited and has yet to be described for the Chilean strawberry, Fragaria chiloensis. In this study, t...

Fragaria chiloensis (Chilean strawberry) is a native species that produces fruit with an exotic pinkish color and a fruity aroma. It has a non-climacteric pattern of fruit ripening, and it is the mother of the commercial Fragaria x ananassa. The ripening of F. chiloensis fruit seems stimulated by ABA, and a complete set of genes participate in its...

Anthocyanins are plant pigments derived from the phenylpropanoid pathway which are produced in many different species, contributing to defense against stresses by their antioxidant properties. Cultivated tomatoes cannot synthesize flavonoids; however, wild tomatoes such as Solanum chilense and Solanum lycopersicoides have anthocyanin pigmented skin...

Two interesting plants within the Chilean flora (wild and crop species) can be found with a history related to modern fruticulture: Fragaria chiloensis subsp. chiloensis (Rosaceae) and Vasconcellea pubescens (Caricaceae). Both species have a wide natural distribution, which goes from the Andes mountains to the sea (East-West), and from the Atacama...

Expansins are cell wall proteins associated to several processes, including changes in the cell wall during ripening of fruit, which matches softening of the fruit. We have previously reported an increase in expression of specific expansins transcripts during softening of Fragaria chiloensis fruit. Here we characterized three α-expansins. Their ful...

Fruit softening during ripening is mainly a consequence of solubilization and depolymerization of cell wall components mediated by the action of a complex set of enzymes and proteins. In the present work, we performed a comparative study of the changes in physiological properties, cell wall-associated polysaccharide contents and expression of cell...

The equilibrium between protein synthesis and degradation is key to maintaining efficiency in different physiological processes. The proteinase inhibitor cystatin regulates protease activities in different developmental and physiological contexts. Here we describe for the first time the identification and the biological function of the cysteine pro...

Aroma and flavor are important factors of fruit quality and consumer preference. The specific pattern of aroma is generated during ripening by the accumulation of volatiles compounds, which are mainly esters. Alcohol acyltransferase (AAT) (EC 2.3.1.84) catalyzes the esterification reaction of aliphatic and aromatic alcohols and acyl-CoA into esters...

Main distances established between ligands and catalytic residues at the SAAT active site during 5 ns of MD simulations. (A) Distances between the oxygen atom of the alcohols and the carbonylic carbon of the acetyl-CoA (dHO•••O = C-AcCoA); (B) Distances between the oxygen atom of the alcohols and the Nε of the His157 (dHO•••Nε-His157). Distances fo...

Evaluation of non-local environment interactions performed by the atomic empirical mean force potential ANOLEA on each heavy atom in the SAAT model. Negatives energies (on green) represent favorable interactions of the respective residue. (TIFF)

RMSD values of SAAT–acetylCoA–octanol (upper left), SAAT–acetylCoA–hexanol (upper right), SAAT–acetylCoA–benzylalcohol (bottom left) and SAAT–acetylCoA–butanol complexes (bottom right), measured during the 5ns equilibration molecular dynamics simulation. On black is represented the protein backbone, on red the acetylCoA substrate and on green the r...

Ramachandran plot of SAAT model. (TIFF)

Sequence alignment between Vironina synthase (Rauvolfia serpentina) and the AAT of Fragaria ananassa. The highly conserved motifs HXXXD and DFGWG are highlighted in yellow. (TIFF)

2D representation of vdW interactions, between octanol and nonpolar groups in SAAT. The purple arrow represent the hydrogen bond interaction made between the hydroxyl group of octanol and the Nε of His157. (TIFF)

Schematic and 3D representations of the solvent channel in SAAT protein. The upper scheme emphasizes the size difference in volume between the front and back faces of the channel. The former allows the binding of acetyl-CoA and the latter the binding of alcohol substrates. Catalytic residues are represented in sticks and the channel as a molecular...

Average distances for electrostatic interactions made between residues Asp166, Arg177, Arg180 and Asn182 with respect acetyl-CoA during a 5 ns MD simulation (see also Fig 2). (PDF)

Fruit softening is associated to cell wall modifications produced by a set of hydrolytic enzymes and proteins. Expansins are proteins with no catalytic activity, which have been associated with several processes during plant growth and development. A role for expansins has been proposed during softening of fruits, and many fruit-specific expansins...

Mountain papaya ( Vasconcellea pubescens ) is a climacteric fruit that develops a strong and characteristic aroma during ripening. Esters are the main volatile compounds produced by the fruit, and most of them are dependent on ethylene. As esters are synthesized through alcohol acyltransferases (AAT), a full-length cDNA (VpAAT1) was isolated that d...

Fragaria chiloensis is characterized for having great aroma and flavor properties. Using headspace-SPME different volatile compounds were identified and quantified during development and ripening of the fruit. The headspace was dominated by esters, butyl acetate, ethyl acetate, ethyl butanoate and ethyl hexanoate being the most abundant in fully ri...

Fruit softening is associated with cell wall modifications produced by a set of hydrolytic enzymes and proteins. Expansins are proteins with no catalytic activity which have been associated with several processes during plant growth and development. A role for expansins has been proposed during fruit softening, and many fruit-specific expansins hav...

The Chilean strawberry (Fragaria chiloensis) is noted for its good fruit quality characters and is one of the wild parents of the commercial strawberry (Fragaria × ananassa). However, the fruit of the Chilean strawberry shows a higher level of softening than that of F. × ananassa, a factor that can affect its shelf-life and reduce its keeping quali...

Mountain or highland papaya (Vasconcellea pubescens) is a climacteric fruit which develops a strong and characteristic aroma during ripening. The dynamics of aroma volatile production during ripening of whole papaya fruit were analysed by headspace-SPME. The main compounds produced by the fruit were esters (aliphatic and branched) and alcohols: the...

The hypothesis of this research is that the application of time-frequency analysis to the impulse response of mountain papaya (Vasconcellea pubescens) reduces the variability associated with the firmness index measurement yet retains the benefits of a non-destructive technique. Fruit specimens were nondestructively tested for firmness during 14 day...

Mountain papaya fruits (Vasconcella pubescens) were tested for firmness with a nondestructive acoustic method for 14 days after harvest. The response of each fruit was analyzed with the Fourier transform to obtain a firmness index (FI) based on the second resonant frequency and with the Short Time Fourier Transform (STFT) to obtain a spectrogram fr...

Herbivorous insect species with narrow diet breadth are expected to be more prone to genetic differentiation than insect species with a wider diet breadth. However, a generalist can behave as a local specialist if a single host-plant species is locally available, while a specialist can eventually behave as a generalist if its preferred host is not...