ABSTRACT
It is known that members of the bacterial genus Azospirillum can promote the growth of a great variety of plants, an ability harnessed by the industry to create bioproducts aimed to enhance the yield of economically relevant crops. Its versatile metabolism allows this bacterium to adapt to numerous environments, from optimal to extreme or highly polluted. The fact of having been isolated from soil and rhizosphere samples collected worldwide and many other habitats proves its remarkable ubiquity. Azospirillum rhizospheric and endophytic lifestyles are governed by several mechanisms, leading to efficient niche colonization. These mechanisms include cell aggregation and biofilm formation, motility, chemotaxis, phytohormone and other signaling molecules production, and cell-to-cell communication, in turn, involved in regulating Azospirillum interactions with the surrounding microbial community. Despite being infrequently mentioned in metagenomics studies after its introduction as an inoculant, an increasing number of studies detected Azospirillum through molecular tools (mostly 16S rRNA sequencing) as part of diverse, even unexpected, microbiomes. This review focuses on Azospirillum traceability and the performance of the available methods, both classical and molecular. An overview of Azospirillum occurrence in diverse microbiomes and the less-known features explaining its notorious ability to colonize niches and prevail in multiple environments is provided.
Subject(s)
Azospirillum , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 16S/metabolism , Azospirillum/genetics , Azospirillum/metabolism , Plant Growth Regulators/metabolism , Plants/microbiology , Signal Transduction , Rhizosphere , Plant Roots/microbiology , Soil MicrobiologyABSTRACT
The use of Azospirillum brasilense as a crop inoculant has increased in recent years. Thus, the compatibility of the inoculation technology with seed treatments using pesticides needs to be evaluated. In this study, we evaluated the effect of an insecticide and fungicide formulation on A. brasilense strain FP2 population by culturing and culture-independent approaches. In addition, we evaluated the impact of these pesticides on the ability of A. brasilense to promote plant growth by monitoring biometric traits (root and shoot dry mass and length) of wheat grown in Greenhouse conditions. Seed pesticide dressings, mainly fungicide, led to a significant mortality of A. brasilense over time. The ability of A. brasilense to promote wheat growth also decreased due to pesticide treatments combined with sowing delay. Considering that pesticides confer fitness advantages to the wheat in field condition, our results suggest that sowing within the first 4 h after inoculation maintain the beneficial effects of A. brasilense on wheat growth promotion. Furthermore, we conclude that inoculation and treatment of seeds with pesticides may be compatible techniques when carried out immediately before sowing.
Subject(s)
Azospirillum brasilense , Fungicides, Industrial , Insecticides , Fungicides, Industrial/pharmacology , Insecticides/pharmacology , Plant Roots , Seeds , TriticumABSTRACT
Twenty-one eyes of 21 patients with refractory glaucoma underwent glaucoma surgery involving placement of a modified Molteno implant and intraoperative application of mitomycin C. Sixteen eyes (76.2%) had an intraocular pressure (IOP) of 21 mm Hg or less after a mean follow up of 9.4 +/- 6.4 months; additional medication was needed in six eyes. Major complications included early flat anterior chamber (42.9%), implant plate erosion (9.5%), tube erosion (4.8%), late hypotony (4.8%), tube-corneal touch (4.8%), and phthisis bulbi after choroidal hemorrhage (4.8%). Only one patient had a high IOP due to decreased filtration through the implant. These results suggest that glaucoma implant surgery with the adjunctive use of mitomycin C may be useful in eyes with refractory glaucoma.
Subject(s)
Glaucoma/surgery , Mitomycin/therapeutic use , Molteno Implants , Adult , Aged , Biocompatible Materials , Chemotherapy, Adjuvant , Female , Fibrosis/drug therapy , Follow-Up Studies , Humans , Intraocular Pressure , Male , Middle Aged , Postoperative Complications/drug therapy , Prognosis , Silicone ElastomersSubject(s)
Middle Aged , Humans , Female , Vitreous Body , Surgical Equipment , Surgical Instruments , Surgical Procedures, OperativeABSTRACT
26 pacientes (27 olhos) que apresentaram degrau nasal bem definido no campo visual foram estudados com o intuito de se verificar com quais miras o degrau nasal e mais encontrado e em que posicao do campo visual incide com maior frequencia. Em 70,3% o degrau foi detectado com a mira de 12e e encontra-se mais ou menos homogeneamente distribuido dos 20 graus aos 50 graus. O presente trabalho enfatiza a necessidade de estudo cuidadoso do campo visual com varias isopteras, para que nao se considere como normal um campo visual nitidamente alterado pelo glaucoma
Subject(s)
Visual Field Tests , Visual FieldsABSTRACT
12 pacientes portadores da arteria cilio-retiniana observados pela oftalmoscopia foram estudados do ponto de vista angiofluoresceinografico. Em 4 (33,3%) pacientes constatou-se a presenca de arteria cilio-retiniana falsa. Nao houve diferenca entre as pressoes medidas com oftalmodinamometro de Bailliart nas arteria central de retina e cilio-retiniana verdadeira
Subject(s)
Arteries , Fluorescein Angiography , RetinaABSTRACT
O endotelio de corneas de coelhos foi submetido a perfusao "in vitro" utilizando-se o sistema de perfusao com microscopia especular de Maurice. As solucoes utilizadas como perfusato foram GBR e prostaglandinas. Nao se conseguiu evidenciar uma possivel acao das prostaglandinas nas alteracoes da espessura corneana
Subject(s)
Cornea , ProstaglandinsABSTRACT
Apresentacao de 1 caso de coloboma do nervo optico com descolamento total de retina, estando a mesma situada dentro do canal optico, com aspecto lobulado. A raridade do processo e a possivel confusao diagnostica com tumoracao intra-ocular e lembrada
Subject(s)
Coloboma , Optic Nerve , Retinal DetachmentABSTRACT
39 estereofotos do nervo optico foram selecionadas todas de pacientes com defeito de campo visual. A incidencia do defeito localizado na camada de fibras nervosas foi de 6%.Em um caso, havia no local correspondente no disco optico uma hemorragia recente. Estes achados foram discutidos
Subject(s)
Glaucoma , Nerve Fibers , Optic NerveABSTRACT
Os autores apresentam um estudo comparativo da flutuacao da pressao intra ocular entre os dois olhos de individuos com hipertensao ocular. 62,9% das medidas de pressao realizadas atraves da curva tensional diaria mostraram flutuacoes sincronicas. 32,4% apresentaram aumento ou diminuicao em um olho enquanto o olho contra lateral mantinha-se inalterado.Apenas 4,6% mostraram inversao dos padroes de flutuacao, fato este que podera ter importancia na avaliacao da eficacia da droga a ser utilizada em pacientes que precisam ter seus niveis pressoricos oculares reduzidos
