Boron influence on concentration of polyols and other sugars in Eucalyptus

Abstract

-Although the functions of the element Boron (B) in plants have not been sufficiently clarified, several hypotheses have been raised. Some of the functions attributed to this element are synthesis and transport of carbohydrates. To evaluate the effect of B on the synthesis of some polyols and sugars in Eucalyptus grandis and hybrids "urograndis", these species were submitted to situations of supply and restriction of B. The experiment was carried out in a greenhouse, arranged in a randomized block design in a 2 x 2 factorial scheme, with 5 replicates of each genotype. The B levels were provided in the form of nutrient solution. No significant difference was observed in the content of mannitol, sorbitol, myo-inositol and scyllo-inositol and sugars α-glucose and β -glucose between E. grandis and hybrids. Arabinose was the only one to present a higher content in E. grandis on restriction of B. The effect of the presence of B was very expressive, but regarding B supply, the plants showed significant increase in the synthesis of the compounds evaluated.Keywords: Mannitol, metabolism of sugars in plants and sorbitol. INFLUÊNCIA DO BORO NA SÍNTESE DE POLIÓIS E OUTROS AÇÚCARES EM Eucalyptus RESUMO -Embora a função do elemento Boro (B) nas plantas ainda não tenha sido bem esclarecida, várias hipóteses vêm sido levantadas. Uma das funções atribuídas a esse elemento é a síntese de carboidratos. Com o objetivo de avaliar o efeito do B sobre a síntese de alguns polióis e açúcares em

Aplicación de boro en eucalipto: comparación de fuentes

“…El B es considerado inmóvil a través del floema para la mayoría de las plantas (incluidos los eucaliptos), aunque existen algunos reportes en los cuales muestra mayor movilidad, asociado a la producción de cantidades significativas de polioles (LEITE et al, 2008;BROWN;SHELP, 1997). Cuando se comporta como inmóvil, al no poder ser retranslocado, se requiere un aporte constante que satisfaga las demandas en cada momento (MENGEL; KIRKBY, 2001).…”

Nutrient partitioning among the roots, hedge and cuttings of Corymbia citriodora stock plants

“…The proportion of total plant B removed through the harvest of cuttings (15-31%) reflected the biomass allocation to cuttings (Table 1), as it did during the harvest of cuttings from E. urophylla (Neto et al, 2012). B is an immobile nutrient in many plant species where sucrose is the primary photoassimilate, but it is mobile in species that contain polyols such as sorbitol and mannitol (Miwa et al, 2009;Lehto et al, 2010) E. grandis and E. grandis × E. urophylla are rich in sorbitol and mannitol (Leite et al, 2008(Leite et al, , 2010, and B appears to be mobile in E. grandis × E. urophylla (Mattiello et al, 2009). Consistent relationships between B concentration and rooting percentage have been found in cuttings of C. citriodora, E. cloeziana and E. dunnii (Trueman et al, 2013a, b), and rooting percentages in three E. grandis × E. urophylla clones have been related to the concentration of B but not N, P, K or Ca (Cunha et al,2009a, b).…”

Determinação do teor de carboidratos em minicepas de Eucalyptus benthamii

“…A solução nutritiva isenta de Zn e B (S1) induziu maior acúmulo de frutose nos tecidos foliares das minicepas de Eucalyptus benthamii, indicando uma correlação da nutrição mineral com o acúmulo dessa forma de carboidrato nos tecidos foliares apicais. Resultado semelhante foi reportado por Leite et al (2008) que verificaram aumento do teor foliar de arabinose na ausência de boro para Eucalyptus grandis. Contudo, em outro estudo, a suplementação de B na solução nutritiva induziu aumento do acúmulo dos teores foliares de manitol e sorbitol para Eucalyptus grandis x Eucalyptus urophylla e Eucalyptus grandis (Leite et al, 2010), sendo que os autores sugerem estreita correlação do elemento B com a síntese de carboidratos específicos e a sua mobilidade na planta.…”