Chin J Plan Ecolo ›› 2015, Vol. 39 ›› Issue (1): 104-109.DOI: 10.17521/cjpe.2015.0011

• Orginal Article • Previous Articles     Next Articles

Analysis of the relationship between cyanide-resistant respiration and photosynthesis under light in Phaseolus vulgaris leaves

FENG Han-Qing*(), GUAN Dong-Dong, JIAO Qing-Song, JIA Ling-Yun, SUN Kun   

  1. College of Life Sciences of Northwest Normal University, Lanzhou 730070, China
  • Received:2014-05-29 Accepted:2014-10-21 Online:2015-01-10 Published:2015-01-22
  • Contact: Han-Qing FENG
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    # Co-first authors

Abstract: Aims

In order to further understand the inner mechanism of plant respiration and the relationship between respiration and photosynthesis of plant under light, our objective was to reveal the relationship between cyanide-resistant respiration and photosynthesis in bean (Phaseolus vulgaris) leaves under light.

<i>Methods</i>

By exposing the dark-grown leaves to light for 10 h, changes in total respiration (Vt), the cyanide-resistant respiration (Valt), photosynthetic O2 evolution, and photosynthetic CO2 fixation, and the effects of inhibitor of the cyanide-resistant respiration on photosynthesis were measured and analyzed. We also measured and analyzed changes in the ratio of cyanide-resistant respiration, total respiration, and photosynthetic CO2 fixation when leaves in the dark were exposed to a brief period (10 min) of light. Important findings After exposing the dark-grown leaves to light for 10 h, Vt, Valt, and the value of Valt/Vt all increased. During the process, time-course analysis after the onset of illumination demonstrated that the induction of the cyanide-resistant respiration in light was prior to the formations of the photosynthetic O2 evolution and CO2 fixation. This observation indicates that the induction of the cyanide-resistant respiration by light is independent of photosynthesis. The dark-grown leaves pretreated with 1 mmol·L-1 salicylhydroxamic acid (SHAM; the inhibitor of the cyanide-resistant respiration) were exposed to illumination for 10 h, and SHAM did not result in apparent modification of the photosynthetic O2 evolution and CO2 fixation in the leaves when exposed to light. This observation also showed that there was no direct linkage between photosynthesis and the cyanide-resistant respiration when the dark-grown leaves were exposed to light. In addition, under the condition of darkness, 10 min of light illumination obviously increased the value of Valt/Vt but did not significantly affect the level of photosynthetic CO2 fixation.

Results

indicate that the induction of the cyanide-resistant respiration by light may be independent of photosynthesis. Light should have a direct influence on induction of the cyanide-resistant respiration.

Key words: cyanide-resistant respiration, light illumination, photosynthesis