J. Phys. IV France 125 (2005) 861-864
DOI: 10.1051/jp4:2005125199

Photoacoustic study of ethylene emission and respiration rate of carbon dioxide from insulin germinated beans (Phaseolus vulgaris L.)

M. Baptista-Filho¹, S.F. Corrêa¹, L.B. da Silva², J. Xavier-Filho², J.G. de Oliveira³ and H. Vargas<sup>1

1</sup>  Laboratório de Ciências Físicas, Universidade Estadual do Norte Fluminense, Rio de Janeiro, Brazil
²  Laboratório de Química e Função de Proteínas e Peptídeos, Universidade Estadual do Norte Fluminense, Rio de Janeiro, Brazil
³  Laboratório de Melhoramento Genético Vegetal, Universidade Estadual do Norte Fluminense, Rio de Janeiro, Brazil

e-mail: vargas@uenf.br

Abstract
Photoacoustic (PA) technique was used to study ethylene and CO₂ respiration emission rates from germinating bean (Phaseolus vulgaris L) seeds. The concentration of ethylene was measured at 10P(12) and 10P(14) lines of the CO₂ laser with the PA cell in the intracavity configuration. On the other hand, the respiration rate of CO₂ was deduced (precision 1 ppm) from the concentration data measured by the commercial PA analyser operating in the infrared range. The objective of this study was to obtain better understanding of insulin signalling in the germinating seeds. The experiments were performed with seeds imbibed either in water or in aqueous solution of insulin (0,9 g.mL^-1 H₂O).

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