Carbon pools and microbial indicators in vineyard soils under organic and conventional fertilization in the São Francisco Valley, in a semi-arid tropical climate.

Soil management systems that do not prioritize conservation contribute to carbon (C) depletion in tropical environments. In the semi-arid region of Brazil, fruit farming has been a key driver for economic development, yet high agricultural yields depend on the use of costly inputs. We conducted a groundbreaking study in São Francisco Valley, northeastern Brazil, to investigate the effects of organic (OF) and synthetic fertilizers (CF) on carbon stock and stability, organic matter fractions, microorganismal carbon biomass (C-mic) and quality indexes, and C-CO emissions up to the 1 m of depth in grapevine soils.

Screening cv. Suvernola Endophytic Bacteria for Maize Growth Promotion.

The search for sustainable agriculture has increased interest in using endophytic bacteria to reduce fertilizer use and increase stress resilience. Stress-adapted plants are a potential source of these bacteria. Some species of these plants have not yet been evaluated for this, such as pangolão grass, from which we considered endophytic bacteria as potential plant growth promoters.

The role of dung beetle species in nitrous oxide emission, ammonia volatilization, and nutrient cycling.

This study evaluated the role of dung beetle species alone or associated under different species on nitrous oxide (NO) emission, ammonia volatilization, and the performance of pearl millet [Pennisetum glaucum (L.)]. There were seven treatments, including two controls (soil and soil + dung without beetles), single species of Onthophagus taurus [Shreber, 1759] (1), Digitonthophagus gazella [Fabricius, 1787] (2), or Phanaeus vindex [MacLeay, 1819] (3); and their assemblages (1 + 2 and 1 + 2 + 3).

Gene expression analyses in tomato near isogenic lines provide evidence for ethylene and abscisic acid biosynthesis fine-tuning during arbuscular mycorrhiza development.

Plant responses to the environment and microorganisms, including arbuscular mycorrhizal fungi, involve complex hormonal interactions. It is known that abscisic acid (ABA) and ethylene may be involved in the regulation of arbuscular mycorrhiza (AM) and that part of the detrimental effects of ABA deficiency in plants is due to ethylene overproduction. In this study, we aimed to determine whether the low susceptibility to mycorrhizal colonization in ABA-deficient mutants is due to high levels of ethylene and whether AM development is associated with changes in the steady-state levels of transcripts of genes involved in the biosynthesis of ethylene and ABA.

Legume-rhizobia signal exchange: promiscuity and environmental effects.

Although signal exchange between legumes and their rhizobia is among the best-known examples of this biological process, most of the more characterized data comes from just a few legume species and environmental stresses. Although a relative wealth of information is available for some model legumes and some of the major pulses such as soybean, little is known about tropical legumes. This relative disparity in current knowledge is also apparent in the research on the effects of environmental stress on signal exchange; cool-climate stresses, such as low-soil temperature, comprise a relatively large body of research, whereas high-temperature stresses and drought are not nearly as well understood.

Mimosa caesalpiniifolia rhizobial isolates from different origins of the Brazilian Northeast.

Biological nitrogen fixation from the legume-rhizobia symbiosis is one of the main sources of fixed nitrogen on land environments. Diazotrophic bacteria taxonomy has been substantially modified by the joint use of phenotypic, physiological and molecular aspects. Among these molecular tools, sequencing and genotyping of genomic regions such as 16S rDNA and repetitive conserved DNA regions have boosted the accuracy of species identification.