Chinese Bulletin of Botany ›› 2018, Vol. 53 ›› Issue (6): 773-781.DOI: 10.11983/CBB17195

• EXPERIMENTAL COMMUNICATIONS • Previous Articles     Next Articles

Differences in Photosynthetic Pigments and Photosynthetic Enzyme Activities in Different Internodes of Phyllostachys edulis During Rapid Growth Stage

Sun Jianfei, Zhai Jianyun, Ma Yuandan*(), , Fu Lucheng, Bu Keli, Wang Keyang, Gao Yan, Zhang Rumin   

  1. The State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and Forestry University, Lin'an 311300, China
  • Received:2017-10-22 Online:2018-11-01 Published:2018-12-05
  • Contact: Ma Yuandan

Abstract:

This study aimed to reveal the characteristics of photosynthetic carbon assimilation and the change regulation in different internodes of Phyllostachys edulis stems during their rapid growth stage. We analyzed the photosynthetic pigment content and activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), phosphoenolpyruvate carboxylase (PEPC), NADP-malate dehydrogenase (NADP-MDH), NADP-malic enzyme (NADP-ME), phosphoenolpyruvate carboxykinase (PEPCK) and pyruvate, and orthophosphate dikinase (PPDK) in stems with different internodes. With increasing internode number of P. edulis stems, the content of chlorophyll a, chlorophyll b and carotenoid was all significantly reduced and the ratio of chlorophyll a/b showed a gradual upward trend. The activities of Rubisco, PEPC and PPDK in stems of P. edulis decreased significantly from the 1st to the 10th internode, then the rate of decrease gradually slowed down. The activities of NADP-ME declined significantly from the 1st to the 13th internode; after the 13th internode, the enzyme activities tended to be stable. The activities of NADP-MDH decreased markedly from 1st to the 25th internode of stems. The ratio of PEPC/Rubisco increased gradually and the range was between 18.37 and 65.09, which was significantly larger than that in typical C3 plants. The research showed that the assimilating capacity with carbon differed in different internodes, and the middle and lower stems grew relatively fast. The result of many C4 enzymes and activities being significantly high provided strong evidence for the existence of a C4 photosynthetic pathway in the stems of P. edulis.

Key words: chlorophyll, C4 pathway, photosynthetic enzyme, Phyllostachys edulis, internode