https://revistaschilenas.uchile.cl/handle/2250/42526 2026-05-06T10:55:25Z https://revistaschilenas.uchile.cl/handle/2250/61045 Induced plant secondary metabolites for phytopatogenic fungi control: a review Pathogenic fungi constitute one of the main infectious agents in plants, causing alterations during developmental stages including post-harvest. Phytopathogenic fungi are controlled by synthetic fungicides; however, the use of these is progressively restricted due to both, the harmful effects of pesticides on the environment and human health and the appearance of highly resistant fungal strains. Therefore, there is a great demand for novel natural fungicides. Higher plants are rich source of bioactive secondary metabolites of wide variety such as tannins, terpenoids, saponins, alkaloids, flavonoids, and other compounds, reported to have in vitro antifungal properties. Thus, secondary metabolites with antifungal activity represent an alternative for achieving a sustainable control of phytopathogenic fungi and to reduce the heavy reliance of synthetic pesticides used to control them. Plant antifungal metabolites may be preformed inhibitors that are present constitutively in healthy plants (phytoanticipins), or they may be synthesized de novo in response to pathogen attack or another stress conditions (phytoalexins). These molecules may be used directly or considered as a precursor for developing better fungicidal molecules. This review presents a selection of antifungal agents induced in plants during fungal attack that can be potentially used for phytopathogenic fungi control in crops. https://revistaschilenas.uchile.cl/handle/2250/61041 Soil and starter fertilizer and its effect on yield and protein composition of malting barley Fertilizer application and growing locations are known to influence yield and protein concentration of malting barley. The aim of the present investigation was to evaluate the influence of soil and starter fertilizer on yield and protein composition in mature and maltedbarley. The cultivar Prestige was grown in two different soils (Lunnarp and LaxmansÅkarp) in combination with the use/non-use of starter fertilizer in climate chambers. Yield parameters, protein concentration and composition was measured. Effect of soil on plant emergence, yield and protein composition was significant while the effect of starter fertilizer was not. More nitrogen rich and low humus content soil (Lunnarp) resulted in higher grain yield and polymerization of proteins and lower protein concentration than the other soil. Combination of soil and starter fertilizer influenced protein composition in mature and malted barley. Breakdown of proteins were significantly higher at certain combination of soil and starter fertilizer than with other combinations. The Lunnarp soil combined with starter fertilizer was preferable to obtain high yield, low protein concentration and large grain size in mature grains. When breakdown of proteins at malting was taken into consideration as well, Lunnarp soil together with no starter fertilizer might be the best option. https://revistaschilenas.uchile.cl/handle/2250/61043 Statistical optimization for improved indole-3-acetic acid (iaa) production by Pseudomonas aeruginosa and demonstration of enhanced plant growth promotion The present study was undertaken to study the statistical optimization of medium components for improved Indole-3- acetic acid (IAA) production by Pseudomonas aeruginosa. Colorimetric analysis showed maximum IAA (132 ìg mL-1) in the medium supplemented with tryptophan (0.5 g L-1). The maximum production was achieved after 96 h of incubation. Yeast extract, tryptophan and EDTA were identified as significant components influencing IAA production by Pseudomonas aeruginosa, using the Plackett- Burman method. The statistical optimization approach led to the production of 318 ìg mL-1 of IAA within 24 h of incubation. Statistical approach was found to be very effective in optimizing the medium components in a manageable number of experimental runs with overall 2.4 fold increase in IAA production. TLC and GC- MS analysis further confirmed the IAA production in the cell filtrates of the strain. GC-MS analysis and tryptophan side chain oxidase confirmed the existence of atleast 2 possible pathways for IAA by this strain. Inoculation of P. aeruginosa culture filtrate enhanced seed germination (82.4%) and increase in root length and shoot length (~ 2.6 and ~ 1.1 folds over the control) of cowpea seeds over the control treatment under pot culture conditions. https://revistaschilenas.uchile.cl/handle/2250/61044 Characterization of humic acids derived from rabbit manure treated by composting-vermicomposting process The aim of this work was to evaluate, through different analytical techniques, the evolution of some chemical and physicochemical properties of humic acid (HA)-like fraction extracted from an organic amendment, like rabbit manure, handle with composting followed by vermicomposting process, in comparison with soil HA, in order to reach an appropriate criterion to evaluate the maturity of an organic amendment. The raw material used was rabbit manure treated with composting followed by vermicomposting process. Soil and organic amendments were analyzed by chemical properties. The HA was extracted from the amendments samples and from an Entic Haplustol and analyzed the chemical and physicochemical characteristics by several analytical methods. Through these analytical techniques was possible to follow the evolution of the HA-like fraction during this stabilization-maturation process Through the composting followed by vermicomposting process the HA-like fraction are evolving toward more stable and complex macromolecule resembling native soil HA.