Metabolic Profile of Strawberry Fruit Ripened on the Plant Following Treatment With an Ethylene Elicitor or Inhibitor.

Strawberry is the most studied nonclimacteric fruit for understanding the role ethylene has in ripening regulation. However, previous studies on the effects of ethylene on strawberry ripening were conducted with detached fruit. Thus, the aim of this work was to determine the effect of ethylene and the ethylene-action inhibitor 1-methylcyclopropene (1-MCP) applied at different developmental stages on important physical-chemical attributes of ripe 'Albion' strawberry. Fruit at four developmental stages that remained attached to the plant were dipped in one of three treatment solutions (Ethephon, 1-methylcyclopropene, and water), plus one absolute control that received no dip. Following treatment, when immature fruit were fully red or 24 h after treatment for red-treated fruit, strawberry fruit were assessed for physicochemical properties (mass, length, diameter, firmness, color, titratable acidity, soluble solids, pH, total phenolics, sugar, organic acid, amino acid, and volatile composition). The days following treatment required for fruit to ripen were also recorded. Treatments did not affect the rate of ripening nor fruit color, titratable acidity, pH, soluble solids, total phenolics, sugars, or organic acids of ripe fruit. Ethephon affected fruit mass, diameter, length, firmness, anthocyanins, amino acids, and volatiles, but these effects were dependent on fruit developmental stage at which the treatment was applied. When green fruit were treated with ethephon, ripe fruit had larger diameter and mass. Ethephon treatment of white fruit resulted in ripe fruit having greater anthocyanin content. Treatment of pink fruit resulted in ripe fruit having smaller diameter, length, and mass and greater firmness. Treatment of red fruit with ethephon altered fruit volatile composition, increasing concentrations of ethyl- and acetate-esters, which were reduced by the 1-MCP treatment. Ethephon treatment increased concentrations of 11 of the 19 free amino acids measured in ripe fruit with treatment of green and white fruit having the greatest effect. A total of 41 volatile compounds had significant correlations with 14 amino acids. While ethylene did not stimulate typical ripening of strawberry fruit, it does appear to alter fruit development and metabolism. The physiological effects of ethylene on strawberry fruit appear to depend on the developmental stage of the fruit.

Genome of Herbaspirillum seropedicae strain SmR1, a specialized diazotrophic endophyte of tropical grasses.

The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme--GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.

Época de poda e quebra de dormência em videiras cv. Niagara Rosada / Times of prunning and budbreaking in Niagara Rosada vines

O experimento foi conduzido com o objetivo de verificar a eficiência da combinação de cinco concentraçõesde cianamida hidrogenada (CH) e quatro épocas de poda, na quebra da dormência e antecipação dacolheita da videira ‘Niagara Rosada’ no município de Ponta Grossa – PR. O delineamento experimentalfoi em blocos casualizados no esquema fatorial 4 x 5 (épocas de poda x concentrações de CH) , com 3repetições e 3 plantas por parcela. Foram analisados a porcentagem de brotação, o número de cachos porplanta, a produção por planta e a massa média dos cachos. Houve efeito da aplicação de cianamidahidrogenada no aumento da brotação das gemas apenas para a primeira época de poda (06/08/2007). Aprimeira época de poda antecipou em uma semana a colheita, embora a ocorrência de geadas tenhaprejudicado a produção. O atraso na época de poda proporcionou um maior número de cachos por plantae a maior produção.

This research work had as the aim of verifying the efficiency of five combined concentrations of hydrogencyanamide (CH) in four consecutive pruning times of sprouting vine and harvest anticipation of 'NiagaraRosada' in the county of Ponta Grossa, PR. The experiment had a factorial design (4 x 5) with 3 replicationsand 3 plants per parcel. The analysis were sprouting percentage, number of clusters per plant, rate ofproduction and average weight per cluster. The effect of CH was shown only at the first pruned timewhen sprouting but the occurrence of frosting decreased the yield. The delay in the process of pruningshowed a higher number of cluster per plant, which consequently resulted in yield increase