Soil infertility is a global problem, amendments such as organic fertilizers and mineral fertilizers are used to improve crop yields. However, these fertilizers contain heavy metals as well as essential mineral elements. The objective of the study was to determine the effect of organic and inorganic fertilizer on the accumulation and health risk of heavy metals in tubers. The plants were cultivated at an altitude of 3970 m using four treatments (poultry manure, alpaca manure, island guano and inorganic fertilizer) and a control group. Soil contamination levels and the degree of metal accumulation in the tubers were also determined. As a result, it was found that the use of inorganic fertilizer and poultry manure increased the values of Cu and Zn in soils, exceeding the recommended standards. The accumulation of heavy metals in potato tubers did not exceed the maximum recommended limits with the exception of Pb, which exceeded the limit allowed by the FAO/WHO (0.1 mg kg⁻¹). Poultry manure contributed to the highest accumulation of Zn, Cu and Pb in tubers with 11.62±1.30, 3.48±0.20 and 0.12 ±0.02 mg kg^-1 respectively. The transfer of metals from the soil to the tubers was less than 1. Individual and total non-carcinogenic risk values were less than 1, indicating a safe level of consumption for children and adults. The cancer risk was found to be within an acceptable range. However, poultry manure and inorganic fertilizer treatments had the highest total cancer risk values in both age groups, suggesting a long-term carcinogenic risk.

El género Polylepis (Rosaceae) es el árbol dominante en los ecosistemas altoandinos. Estos ecosistemas están gravemente amenazados y poco se sabe sobre su estructura y funcionamiento. Proporcionamos los primeros reportes de la estructura dasométrica y la distribución espacial de ocho bosques de Polylepis canoi, P. flavipila y P. rodolfo-vasquezii en los Andes Centrales peruanos como información fundamental para el manejo y políticas de conservación. En cada bosque tomamos datos de todos los individuos ≥1 cm de diámetro a nivel del suelo (DNS) en 20 parcelas de 10x10 m y medimos la altura total (AT) y el DNS. Además, mapeamos la distribución espacial de los individuos en dos parcelas de 30x30 m (ejes X e Y). Encontramos diferencias en la estructura dasométrica entre bosques de la misma especie; en algunos casos, estas diferencias se asocian a variables de clima, de suelo o de elevación. Sin embargo, no se encontró un patrón definido. Las relaciones alométricas de los modelos lineales y no lineales no difieren respecto al R2 ni a los valores de Akaike (AIC), lo que indica que los bosques no muestran una saturación de la altura con el incremento del diámetro. En los bosques de P. canoi, los individuos con diámetros ≥10 cm fueron los más abundantes; por el contrario, los bosques de P. rodolfo-vasquezii presentaron predominancia de individuos con diámetros ≤10 cm. Polylepis flavipila mostró una estructura alterada, sin relación entre DNS y AT en uno de los bosques evaluados. Los análisis de distribución espacial según la función K de Ripley a pequeña escala revelaron que P. flavipila y P. canoi poseen patrones aleatorios, mientras que P. rodolfo-vasquezii mostró un patrón agregado. Finalmente, nuestros resultados demuestran que incluso bosques de la misma especie tienen diferentes estructuras dasométricas, mientras que los patrones espaciales difieren sólo entre especies. Por ello, se debe tener cuidado al extrapolar información durante los estudios ecológicos y las acciones de conservación. https://doi.org/10.25260/EA.19.29.3.0.812

RuBisCO is the most abundant enzyme on earth; it regulates the organic carbon cycle in the biosphere. Studying its structural evolution will help to develop new strategies of genetic improvement in order to increase food production and mitigate CO₂ emissions. In the present work, we evaluate how the evolution of sequence and structure among isoforms I, II and III of RuBisCO defines their intrinsic flexibility and residue-residue interactions. To do this, we used a multilevel approach based on phylogenetic inferences, multiple sequence alignment, normal mode analysis, and molecular dynamics. Our results show that the three isoforms exhibit greater fluctuation in the loop between αB and βC, and also present a positive correlation with loop 6, an important region for enzymatic activity because it regulates RuBisCO conformational states. Likewise, an increase in the flexibility of the loop structure between αB and βC, as well as Lys330 (form II) and Lys322 (form III) of loop 6, is important to increase photosynthetic efficiency. Thus, the cross-correlation dynamics analysis showed changes in the direction of movement of the secondary structures in the three isoforms. Finally, key amino acid residues related to the flexibility of the RuBisCO structure were indicated, providing important information for its enzymatic engineering.