Biology subjects

Rodrigues, P. A. P.

Publications and source records attributed to Rodrigues, P. A. P..

2 recordsLinked to original sources

bioRxiv2026

Higher Lipid Saturation in Well-Irrigated Georgia Cotton Plants: A Field-Based NMR Metabolomics Study

Cotton (Gossypium hirsutum) is an economically important crop, but it faces increasing pest outbreaks, especially in non-irrigated areas. In this study, 20 cotton farms using center-pivot irrigation were sampled in southern Georgia to assess chemical differences between non-irrigated and irrigated areas. Proton (1H) nuclear magnetic resonance (NMR) data were obtained from cotton leaves, and Principal Component Analysis (PCA) was performed to assess differences in chemical composition. Across all samples, farm site accounted for most of the variability, but within each farm site, the PCA scores plots showed clear separation between non-irrigated and irrigated conditions in 10 sites. Inspecting the PCA loadings revealed significant resonances resembling a lipid-like signal. After reverse-phase fractionation, we observed that many of these resonances appeared together in later fractions, suggesting a lipid, specifically a fatty acid such as linoleic acid. We hypothesized that differences in net lipid saturation level may drive separation between non-irrigated and irrigated samples. Six farm sites had a significantly or marginally significantly higher degree of unsaturation in irrigated samples, while one farm site had significantly higher unsaturation in non-irrigated samples. Our results indicate that drought stress likely affects lipid profile composition, which could be driving higher herbivorous pest densities in drought-stressed crops.

plant biology↗

bioRxiv2023

Host plant affects the larval gut microbial communities of the generalist herbivores Helicoverpa armigera and Spodoptera frugiperda

Investigations on symbiotic associations between Lepidoptera and bacteria have been inconclusive as to whether these microorganisms represent transient or persistent associations. One reason for this is that most studies have sampled the microbiota from only a few species and frequently from laboratory-reared animals. We sequenced the 16S rRNA gene to profile the gut microbiome of the field collected, agricultural pests Helicoverpa armigera and Spodoptera frugiperda. We found that variation in the structure of bacterial communities is in great part associated with their host diet. Moreover, Enterococcus, among a few other taxa, is consistently present in all samples regardless of the plant hosts were collected. The larval gut bacteria composition matches previously published data in the same or related species, indicating that associations with bacteria taxa such as Enterococcus are persistent despite geographical variation and sampling techniques. Based on our phylogenetic analysis it is not clear, however, if Enterococci associated with Lepidoptera are necessarily different from environmental bacteria. We conclude that to fully understand the nature of Lepidoptera - gut bacteria associations it will be necessary to conduct larger sampling efforts and combine them with identification methods of bacterial strains that go beyond screening of the 16S rRNA gene.

microbiology↗