Homeostasis in cucumber plants during low temperature stress

Shoots, roots and whole plants of Cucumis sativus L. cv. Inspektowy Warszawski were subjected to different temperatures. The magnitude and direction of alterations of growth depended on the organ that was submitted to stress conditions. Changes in soluble protein level in leaves and in roots were inversely correlated with changes of total organic nitrogen level in both organs. In spite of differentiated temperature conditions between plant organs, the allometric coefficients and the ratio between maintenance respiration in shoot and in roots remained constant. Such constancy may be treated as an indicator of homeostasis of the whole-plant system. The results point to the importance of both shoot and roots in the response of the plant to temperature stress.