Comparative proteomic analysis of papaya bud flowers reveals metabolic signatures and pathways driving hermaphrodite development.

Papaya (Carica papaya) is a trioecious species with female, male, and hermaphrodite plants. Given the sex segregation, selecting hermaphroditic plants is vital for orchard establishment due to their greater commercial value. However, selecting hermaphrodite plants through sexing is laborious and costly. Moreover, environmental stressors can exacerbate the issue by potentially inducing abnormal flower development, thus affecting fruit quality. Despite these challenges, the molecular mechanisms governing sex development in papaya remain poorly understood. Thus, this study aimed to identify proteins associated with sex development in female and hermaphrodite flowers of papaya through comparative proteomic analysis. Proteins from flower buds at the early and late developmental stages of three papaya genotypes (UENF-CALIMAN 01, JS12, and Sunrise Solo 72/12) were studied via proteomic analysis via the combination of the shotgun method and nanoESI-HDMSE technology. In buds at an early stage of development, 496 (35.9%) proteins exhibited significantly different abundances between sexes for the SS72/12 genotype, 139 (10%) for the JS12 genotype, and 165 (11.9%) for the UC-01 genotype. At the final stage of development, there were 181 (13.5%) for SS72/12, 113 (8.4%) for JS12, and 125 (9.1%) for UC-01. The large group of differentially accumulated proteins (DAPs) between the sexes was related to metabolism, as shown by the observation of only the proteins that exhibited the same pattern of accumulation in the three genotypes. Specifically, carbohydrate metabolism proteins were up-regulated in hermaphrodite flower buds early in development, while those linked to monosaccharide and amino acid metabolism increased during late development. Enrichment of sporopollenin and phenylpropanoid biosynthesis pathways characterizes hermaphrodite samples across developmental stages, with predicted protein interactions highlighting the crucial role of phenylpropanoids in sporopollenin biosynthesis for pollen wall formation. Most of the DAPs played key roles in pectin, cellulose, and lignin synthesis and were essential for cell wall formation and male flower structure development, notably in the pollen coat. These findings suggest that hermaphrodite flowers require more energy for development, likely due to complex pollen wall formation. Overall, these insights illuminate the molecular mechanisms of papaya floral development, revealing complex regulatory networks and energetic demands in the formation of male reproductive structures.

Diversity and genetic structure of natural populations of the palm tree Euterpe precatoria (Arecaceae) / Diversidad y estructura genética de poblaciones naturales de la palmera Euterpe precatoria (Arecaceae)

Abstract Introduction: The natural ecosystems of northern Mato Grosso, Brazil, are in process of fragmentation, mainly due to population growth and the expansion of agriculture. This endangers the palm Euterpe precatoria (locally known as açaí), used for construction, palm hearts, juices and ice cream. Objective: To evaluate the local diversity and genetic structure in native populations of E. precatoria. Methods: We collected leaves from 106 fruiting palms from five populations in Mato Grosso State, for analysis of microsatellite markers with Polymerase Chain Reaction. Results: The five SSR loci revealed a total of 30 alleles, ranging from 5 (EE23 and EE43) to 7 (EE2 and EE15), with an average of 6 alleles per locus. The mean PIC was 0.74 and confirmed low heterozygosity and inbreeding. The UPGMA dendrogram produced two groups and molecular variance revealed greater genetic differentiation within populations. The high levels of homozygous microsatellite loci indicate low genetic diversity. Conclusions: These populations have low gene diversity, high average number of alleles per locus, and rare and exclusive alleles. We recommend the establishment of permanent conservation units with corridors among them.

Resumen Introducción: Los ecosistemas naturales del norte de Mato Grosso, Brasil, están en proceso de fragmentación, principalmente debido al crecimiento de la población y la expansión de la agricultura. Esto pone en peligro la palma Euterpe precatoria (localmente conocida como açaí), utilizada para la construcción, extracción de palmito, preparación de jugos y helados. Objetivo: Evaluar la diversidad local y estructura genética en poblaciones nativas de E. precatoria. Métodos: Recolectamos hojas de 106 palmas fructíferas de cinco poblaciones en el estado de Mato Grosso, para análisis de marcadores microsatélites con el método de Reacción en Cadena de la Polimerasa (PCR). Resultados: Los cinco loci SSR revelaron un total de 30 alelos, que van desde 5 (EE23 y EE43) hasta 7 (EE2 y EE15), con un promedio de 6 alelos por locus. El PIC medio fue de 0.74 y confirmó baja heterocigosidad y endogamia en las poblaciones. El dendrograma UPGMA produjo dos grupos y la varianza molecular reveló una mayor diferenciación genética dentro de las poblaciones. Los loci de microsatélites presentaron un alto nivel de homocigotos lo que indica una baja diversidad genética. Conclusiones: Estas poblaciones tienen baja diversidad genética, alto promedio de alelos por locus y alelos raros y únicos. Recomendamos el establecimiento de unidades de conservación permanentes con corredores entre ellas.

Avaliação do potencial citogenotóxico de Zingiber officinale Roscoe (gengibre), Zingiberaceae / Evaluation of the cytogenotoxic potential of Zingiber officinale Roscoe, Zingiberaceae (ginger)

Introdução: A história da civilização humana está intimamente relacionada à utilização de plantas para prevenção e tratamento de doenças. Dentre as plantas utilizadas pela medicinal tradicional está o Zingiber officinale Roscoe (Zingiberaceae), que apresenta-se também como uma espécie promissora no combate ao câncer. Objetivo: Avaliar o potencial citotóxico e genotóxico de extratos aquosos e hidroalcoólico de Z. officinale. Métodos: Bulbos de Allium cepa L. (Amaryllidaceae) foram submetidos ao tratamento descontínuo e, após o enraizamento, transferidos para cinco concentrações dos extratos de Z. officinale , para o controle negativo (água destilada) e para o controle positivo (glifosato 1 %). O experimento foi mantido em câmara de germinação, com temperatura controlada (± 25 °C) e ausência de luz, por um período de 48 horas após exposição aos extratos. Resultados: O índice mitótico foi afetado por todas as concentrações e extratos testados, diferindo significativamente do controle negativo. O extrato hidroalcoólico promoveu maior redução no índice mitótico, não diferindo estatisticamente do controle positivo. A quantidade de células com anormalidades e aberrações cromossômicas foi pequena e não significativa. Conclusão: A espécie apresenta potencial para pesquisas relacionadas à prevenção e ao tratamento de tumores e os resultados obtidos reiteram a importância de estudos sobre a toxicidade de plantas medicinais e a orientação para utilização adequada pela medicina tradicional.

Introduction: The history of human civilization is closely linked to the use of plants for disease prevention and treatment. One of the plants used in traditional medicine is Zingiber officinale Roscoe (Zingiberaceae), which is also a promising species against cancer. Objective: Evaluate the cytotoxic and genotoxic potential of Z. officinale aqueous and hydroalcoholic extracts. Methods: Allium cepa L. (Amaryllidaceae) bulbs were subjected to discontinuous treatment and after rooting they were transferred to five different concentrations of Z. officinale extracts. Distilled water was used as negative control and 1 % glyphosate as positive control. The experiment was kept in a germination chamber at controlled temperature (± 25 °C) and absence of light for a period of 48 hours after exposure to the extracts. Results: The mitotic index was affected by all the concentrations and extracts tested, and it was significantly different from the negative control. The hydroalcoholic extract caused a greater reduction in the mitotic index, but it was not statistically different from the positive control. The number of cells with chromosomal abnormalities and aberrations was small and non-significant. Conclusions: The study species is a potential topic for future research about tumor prevention and treatment. The results obtained confirm the importance of further studies on the toxicity of medicinal plants and the indications for their appropriate use in traditional medicine.