Bactérias endofíticas promotoras de crescimento de plantas em mudas de pupunheira

The objective of this work was to isolate endophytic bacteria from peach palm (Bactris gasipaes var. gasipaes) plants and to evaluate the effects of their inoculation on the plant seedlings. Bacteria were isolated from the leaves and roots of the seedlings and from the meristems of peach palm plants in vitro. The isolates were characterized phenotypically and, then, 15 of them, representing different phenotypic groups, were selected and identified by partial sequencing of the 16S rRNA gene. Afterward, these isolates and two commercial strains of Azospirillum brasilense (Ab-V5 and Ab-V6) were inoculated in the peach palm seedlings. After 76 days, the seedlings were evaluated for plant development. The following six genera were identified based on the sequencing: Pseudomonas, Enterobacter, Rhizobium, Stenotrophomonas, Klebsiella, and Erwinia. Out of the 15 inoculated isolates, 9 had a positive effect on the root dry mass of palm peach, with CNPF 77 (Enterobacter sp.), CNPF 100 (Rhizobium sp.), and CNP 179 and CNPF 277 (Stenotrophomonas sp.) standing out. Peach palm seedlings harbor endophytic bacteria which are able to increase root dry matter.O objetivo deste trabalho foi isolar bactérias endofíticas de pupunheira (Bactris gasipaes var. gasipaes) e avaliar os efeitos da inoculação delas em mudas da planta. As bactérias foram isoladas de folhas e raízes das mudas e de meristemas de pupunheira in vitro. Os isolados foram caracterizados fenotipicamente, e, depois, 15 deles, representando grupos fenotípicos distintos, foram selecionados e identificados por meio do sequenciamento parcial do gene 16S rRNA. Em seguida, esses isolados e duas estirpes comerciais de Azospirillum brasilense (Ab-V5 e Ab-V6) foram inoculados em plântulas de pupunheira. Após 76 dias, as mudas foram avaliadas quanto ao desenvolvimento vegetal. Foram identificados os seis seguintes gêneros com base no sequenciamento: Pseudomonas, Enterobacter, Rhizobium, Stenotrophomonas, Klebsiella e Erwinia. Dos 15 isolados inoculados, 9 tiveram efeito positivo sobre a massa de matéria seca de raízes, com destaque para CNPF 77 (Enterobacter sp.), CNPF 100 (Rhizobium sp.), e CNP 179 e CNPF 277 (Stenotrophomonas sp.). Mudas de pupunheira abrigam bactérias endofíticas capazes de aumentar a matéria seca das raízes

Bacillus megaterium: bacteria endofítica de callos de Ilex paraguariensis con actividad de promoción del crecimiento

Los microorganismos endófitos viven dentro de plantas sanas y su aislamiento e identificación pueden favorecer las aplicaciones biotecnológicas. Los microorganismos endofíticos fueron encontrados en callos de Ilex paraguariensis cultivados in vitro durante cinco meses. Se usó la secuenciación de la región 16S rRNA para identificar dos aislados como Bacillus megaterium. La presencia de células bacterianas en los espacios intercelulares de los cultivos de callos se detectó mediante análisis ultraestructurales. Los aislamientos también se evaluaron para la producción de ácido indol acético (AIA) y su potencial en la promoción del crecimiento de las plántulas de Phaseolus vulgaris L. La síntesis de ácido AIA en presencia y ausencia de L-triptófano se detectó por análisis colorimétrico para ambos aislamientos. En presencia de extractos de las cepas IPC06 e IPC07, las plántulas de P. vulgaris crecieron más rápido en comparación con las plantas control sin el extracto en pruebas in vitro.Palabras clave: yerba mate, 16S rRNA, secuenciación, cultivo de tejido

INDIRECT ORGANOGENESIS FROM LEAF EXPLANTS AND IN VITRO SHOOTS LTIPLICATION OF Eucalyptus benthamii X Eucalyptus dunnii

Os objetivos deste trabalho foram avaliar diferentes meios de cultura na organog\ueanese indireta e na multiplica\ue7\ue3o in vitro de brotos de Eucalyptus benthamii x Eucalyptus dunnii . Para organog\ueanese, explantes foliares foram excisados no sentido transversal e cultivados in vitro, sendo os seguintes fatores testados: dois meios de cultura (MS N/2 e JADS) adicionados de 0,1 \u3bcM de ANA, duas concentra\ue7\uf5es de thidiazuron (0,1 e 0,5 \u3bcM) e presen\ue7a ou n\ue3o de PVP-40 (250 mg L-1). Ap\uf3s 70 dias de cultivo foram avaliadas as porcentagens de explantes oxidados totalmente, formando calo, produzindo antocianina, formando gema, formando brota\ue7\uf5es e o n\ufamero de brota\ue7\uf5es formadas por explante regenerando. No experimento de multiplica\ue7\ue3o, brota\ue7\uf5es isoladas foram cultivadas em meio MS, JADS e WPM, adicionados de 1,11 \u3bcM de BAP. Foram realizados quatro subcultivos a cada 28 dias e em cada subcultivo foram avaliados: a porcentagem de oxida\ue7\ue3o, de explantes apresentando clorose total ou parcial, massa fresca e n\ufamero m\ue9dio de brotos por explante. O meio de cultura MS N/2 suplementado com 0,1 \u3bcM de ANA, 0,5 \u3bcM de TDZ e PVP-40 promoveu a maior taxa de organog\ueanese (8,3%). No meio de cultura MS com 1,11 \u3bcM de BAP, a taxa de multiplica\ue7\ue3o foi maior que nos outros meios, no primeiro e segundo subcultivos (9,28 e 9,24 por m\ueas), n\ue3o havendo diferen\ue7a entre os tr\ueas meios nos demais subcultivos.The aims of this research were to evaluate different culture media for indirect organogenesis and shoot multiplication of Eucalyptus benthamii x Eucalyptus dunnii . For organogenesis, leaf explants were used to test the following treatments: two culture media (MS N/2 and JADS) supplemented with 0.1 \u3bcM 1-naphthaleneacetic acid (NAA) and thidiazuron (TDZ) (0.1 or 0.5 \u3bcM), with or without PVP- 40 (250 mg L-1). The percentage of oxidized explants, callus forming explants, explants with anthocyanin, buds, shoots and the shoot number per explant were evaluated. In the multiplication experiment, isolated shoots were cultivated in MS, JADS and WPM media, all supplemented with 1.11 \u3bcM BAP. Four subcultures were carried out every 28 days. In every subculture the explant oxidation, partial or total leaf chlorosis, fresh mass and mean number of shoot per explant were evaluated. The MS N/2 medium supplemented with 0.1 \u3bcM NAA and 0.5 \u3bcM TDZ promoted the highest rate of organogenesis (8.3%) and the culture media MS supplemented with 1.11 \u3bcM BAP the multiplication rate was higher than in the other media, in the first and the second subcultures (9.28 and 9.24, respectively), without differences between the three media in the following subcultures

Efeito do meio de cultura na calogênese in vitro a partir de folhas de erva-mate

Organogenesis is a technique rarely studied in the micro propagation of Ilex paraguariensis. This study evaluated different culture media on callus induction and in vitro organogenesis of this species. Leaves were collected from greenhouse grown plants. Leaves segments were placed on culture media ¼ MS, WPM or JADS, containing zeatin and 2,4-D. The MS medium was more efficient in callus inducing. Rooting was observed in the WPM medium. No buds were formed in any of the media evaluated.A organogênese é uma técnica pouco estudada na micropropagação de erva-mate. Este trabalho objetivou avaliar diferentes meios de cultura na calogênese in vitro e organogênese de Ilex paraguariensis St. Hil. Foram coletadas folhas em plantas em casa-de-vegetação. Segmentos foliares foram colocados em meios de cultura ¼ MS, WPM ou JADS, contendo zeatina e 2,4-D. O meio MS foi mais eficiente na indução de calos. No meio WPM foi observada rizogênese. Nos meios testados não houve formação de brotações adventícias

Effect of carbon source on somatic embryogenesis of Bactris gasipaes

A metodologia de camada fina de células foi utilizada com sucesso para indução de embriogênese somática em região do meristema apical de plantas de pupunha mantidas em casa-de-vegetação. O efeito de três fontes de carbono: sacarose, glicose e manitol na indução de embriogênese somática foi avaliado. Embriões somáticos foram observados após a indução apenas nos meios contendo sacarose ou glicose em igual proporção.Thin cell layer of meristematic region was successfully used to induce somatic embryogenesis in greenhouse-grown plants of pejibaye. The effects of three sources of carbohydrates, sucrose, glucose and mannitol on induction of somatic embryogenic calli were evaluated. Somatic embryos were observed on media containing either sucrose or glucose

<i>Bacillus megaterium</i>: bacteria endofítica de callos de <i>Ilex paraguariensis</i> con actividad de promoción del crecimiento

Los microorganismos endófitos viven dentro de plantas sanas y su aislamiento e identificación pueden favorecer las aplicaciones biotecnológicas. Los microorganismos endofíticos fueron encontrados en callos de Ilex paraguariensis cultivados in vitro durante cinco meses. Se usó la secuenciación de la región 16S rRNA para identificar dos aislados como Bacillus megaterium. La presencia de células bacterianas en los espacios intercelulares de los cultivos de callos se detectó mediante análisis ultraestructurales. Los aislamientos también se evaluaron para la producción de ácido indol acético (AIA) y su potencial en la promoción del crecimiento de las plántulas de Phaseolus vulgaris L. La síntesis de ácido AIA en presencia y ausencia de L-triptófano se detectó por análisis colorimétrico para ambos aislamientos. En presencia de extractos de las cepas IPC06 e IPC07, las plántulas de P. vulgaris crecieron más rápido en comparación con las plantas control sin el extracto en pruebas in vitro. Palabras clave: yerba mate, 16S rRNA, secuenciación, cultivo de tejido

OPTIMIZATION OF FACTORS AFFECTING THE Agrobacterium tumefaciens- MEDIATED TRANSFORMATION OF Eucalyptus saligna

ABSTRACT This study aimed to evaluate the effect of factors that may affect the genetic transformation of cotiledonary explants of Eucalyptus saligna mediated by EHA105 strain of Agrobacterium tumefaciens. The vector pBI121 carrying gus gene under control of 35S CaMV promoter was used. The effect of the following factors was evaluated: explant pre-culture, use of different antibiotics and presence of acetosyringone (AS) in co-culture media. An antioxidant solution was also used during excision, containing ascorbic acid (250mg.L-1), citric acid (25mg.L-1) and PVP-40 (1g.L-1). Pre-culture of the explants before the co-culture with bacteria was done over a 4-day period in MS culture medium supplemented with 4.4µM BAP and 2.7ìM NAA. After theco-culture period, three concentrations of kanamycin (12.5;25 and 50mg.L-1) combined with 300mg.L-1 Augmentin® in the culture medium were tested The influence of the antibiotic was also evaluated by keeping the explants in a medium containing 50mg.L-1 Km and 300mg.L-1 Augmentin® or 500mg.L-1 cefotaxime. It was concluded that Augmentin® stimulates organogenesis, that a Km concentration of 12.5mg.L-1 allows selection of explants transformed with gus gene and, finally, the addition of AS (50ìM) to the liquid and solid co-culture media has a positive effect on gus gene expression. Moreover, the use of an antioxidant solution during cotyledon excision is dispensable and the pre-culture of the explants has no effect on bud regeneration or gus gene expression. A transformation efficiency of 1.5% was reached