Diurnal variation in the activity of enzymes of sucrose catabolism in Hymenaea courbaril L. plantlets during storage xyloglucan mobilization

Author(s)

Fábio Reis Dalle Molle ^[1] ; Aline Dias Brandão ^[2] ; Marco Aurélio Silva Tiné ^[3]

Affiliation

^[1] Instituto de Botânica. Seção de Fisiologia e Bioquímica de Plantas - Brasil

^[2] Universidade Estadual de Campinas. Instituto de Biologia. Programa de Pós-Graduação em Biologia Celular e Estrutural - Brasil

^[3] Instituto de Botânica. Seção de Fisiologia e Bioquímica de Plantas - Brasil

• Document type: Journal article
• Source: Rev. bras. Bot.; v. 32, n. 1, p. 143-153, 2009-03-00.

Abstract

Seeds of Hymenaea courbaril L. have a storage polysaccharide that is mobilized after germination, when the first leaf is already photosynthetic. During reserve mobilization, the seedling has to coordinate two carbohydrate sources: photosynthesis and storage mobilisation. Both use sucrose to export carbon. To understand the allocation of carbon resources in the seedling, therefore, it is essential to study the catabolism of sucrose in the organs. In the present work, the low molecular weight carbohydrates were analyzed, as well as the activity of sucrose synthase and of the three isoforms of invertase in organs of Hymenaea courbaril L. seedlings along a day. The analysis was made each 6 hours, with an extra analysis at 2 am. Each enzyme had a characteristic variation pattern along the day, suggesting distinct and independent functions for each organ. The carbohydrate analysis showed higher concentration of sucrose in the sink-organs, while the cotyledons had high concentration of free monosaccharides. The existence of isoforms with distinct properties and cellular distribution varying in independent ways along the day suggests that these isoforms may have distinct physiological functions in the plant. (AU)

• FAPESP's process: 04/10159-8 - Control of the genetic expression of the metabolism of carbohydrates by auxin during the mobilization of reserves and the development of plant embryos of jatoba (Hymenaea courbaril var. Stilbocarpa)
• Grantee: Aline Dias Brandão
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 04/12194-5 - Mapping of the enzymes of the metabolism of sucrose in plantules of Hymenaea courbaril L. during the mobilization of reserve xyloglucan
• Grantee: Fábio Reis Dalle Molle
• Support Opportunities: Scholarships in Brazil - Master