Metabolic responses of plant cell culture to hydrodynamic stress

Authors

  • Toshiya Takeda,

    Corresponding author
    1. Department of Chemistry and Bio-technology, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113, Japan
    • Department of Chemistry and Bio-technology, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113, Japan
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  • Takanori Kitagawa,

    1. Department of Chemistry and Bio-technology, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113, Japan
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  • Yoshikuni Takeuchi,

    1. Department of Chemistry and Bio-technology, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113, Japan
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  • Minoru Seki,

    1. Department of Chemistry and Bio-technology, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113, Japan
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  • Shintaro Furusaki

    1. Department of Chemistry and Bio-technology, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113, Japan
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Abstract

The metabolic responses of eucalyptus and safflower cells to hydrodynamic stress in a 550-cm3 stirred tank reactor were investigated. At 0.5 — 2.3 m2/s3 of energy dissipation rate, the decreases in respiration rate and ATP content were larger than the decrease in the membrane integrity. Intracellular NAD(P)H was decreased and cytosolic calcium content was increased by agitation. EGTA, verapamil and W-7 suppressed the decrease in NAD(P)H. These results suggest that the cytosolic calcium, as a second messenger, mediate the signal of the hydrodynamic stress into the metabolism which induces the decrease in respiration rate. Furthermore, a decrease in the filamentous actin content due to agitation was observed.

Abstract

On a étudié les réponses métaboliques de cellules d'eucalyptus et de carthame aux contraintes hydrodynamiqes dans un réacteur agité de 550 cm3. À un taux de dissipation d'énergie de 0,5-2,3 m2/s3, la diminution de la vitesse de respiration et de la teneur en ATP est de la teneur en ATP est plus importante que la diminution de l'intégrité membranaire. Le NAD(P)H intracellulaire a été réduit et la teneur en calcium cytosolique augmentée par agitation. L'EGTA, le verapamil et le W-7 suppriment la baisse du NAD(P)H. Ces résultats suggèrent que le calcium cytosolique, comme deuxième messager, conduit le signal de contrainte hydrodynamique dans le métabolisme, entraœnant la diminution de la vitesse de respiration. En outre, on a observé une baisse de la teneur en actine filamenteux due à l'agitation.

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