RESUMO
The relationship between agriculture and wildlife can be both synergetic and challenging, as the increased surface of agricultural land makes it increasingly important for agriculture and wildlife to coexist. This study aims to describe the use of freshly drilled dry bean fields by birds and mammals in Brazilian Cerrado and Atlantic Forest sites and their diversity and abundance within in-crop and off-crop areas (with native permanent vegetation and other surrounding crop fields) at four different farms. A comprehensive survey was conducted, using various sampling methods, including point counts, foraging counts, trail cameras, and occasional encounters. In all, contacts for 12 518 birds across 306 species and 313 mammals across 34 species were registered. The off-crop areas exhibited greater species richness, abundance, and diversity than the in-crop areas on all farms. For birds, 47 species were recorded in-crop, of which 15 were classified as insectivores, 15 as granivores, seven as omnivores, seven as carnivores, and three as frugivores. The number of in-crop observations per species was small. The abundance off-crop was greater for 31 species observed in-crop, indicating that dry bean fields are probably not a preferred habitat for those species. Species classified as granivorous are most likely to feed on dry bean seeds. However, almost all granivorous species observed in-crop areas are too small to be able to feed on dry bean seeds. For mammals, nine species were recorded in-crop, of which four were classified as carnivores, three as omnivores, one as insectivore, and one as granivore. Additionally, despite the considerable effort in this study, no evidence was found that birds and mammals feed on dry bean seeds. The results highlight the importance of off-crop areas in dry bean fields, characterized by a more diverse and abundant bird community than in-crop. Integr Environ Assess Manag 2024;20:864-874. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
RESUMO
The first step in sucrose use by maize kernels produces fructose, regardless of whether the initial reaction is catalyzed by an invertase or the reversible sucrose synthase. This fructose can enter subsequent metabolism via hexokinase, or in maize kernels, by a sorbitol dehydrogenase that reversibly converts fructose + NADH to sorbitol + NAD. High levels of SDH activity suggest that kernels synthesize considerable amounts of sorbitol, but the molecular mechanism and functional role for this process have remained equivocal. To gain insights on the role of sorbitol synthesis in maize endosperm we cloned and characterized the transcriptional control of the maize sorbitol dehydrogenase (Sdh1) gene. Data indicated that Sdh1 was essentially kernel- and endosperm-specific, with maximal expression at both the mRNA and enzyme activity levels during early kernel development. Expression was elevated in high-sugar mutants (sugary1, shrunken2), also by sugar injections, and was more pronounced when transfected tissues were incubated at low oxygen concentrations. Control of Sdh1 expression in our transient assays was largely dependent on the first intron of Sdh1. We speculate that SDH activity may represent an adaptation to the high-sugar/low-oxygen environment of the endosperm. Under these conditions, the NADH-dependent reduction of fructose to sorbitol would regenerate NAD[+], thus contributing to the maintenance of the redox and energy status of the cell.
