Journal of Plant Ecology

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Stem photosynthesis is an important factor in the regulation of biomass accumulation and allocation in Rosa chinensis

Hui-Ying Ye1, Zheng-Bing Yan2, Su-Hui Ma1, Xue-Mei Yang1, Chen Yang1, Dan-Hua Zhang1, Jiang-Ling Zhu1, Cheng-Jun Ji1,* and Jing-Yun Fang1   

  1. 1Institute of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China
    2State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China

    *Correspondence: Cheng-Jun Ji
    Email: jicj@pku.edu.cn
    Tel: +86 10 62765578
    Fax: + 86 10 62756560
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (32271668) and the National Key R&D Program of China (2022YFF0802304).

Abstract: Green stem photosynthesis is well known, but the effect of stem photosynthesis on plant growth and development remains uncertain. In this study, green stems of semiannual Rosa chinensis were subjected to a shading treatment to explore the effect of stem photosynthesis on the growth and biomass accumulation. The results showed that (1) Stem photosynthesis affected biomass accumulation and allocation in R. chinensis. The stem shading treatment decreased the biomass of R. chinensis by approximately 18.7%. The proportion of biomass allocated to the stems increased while the proportion of biomass allocated to the leaves and roots decreased. (2) Stem photosynthesis facilitates an increase in nonstructural carbohydrate concentration, chlorophyll a concentration and chlorophyll a/b of R. chinensis. (3) The net photosynthesis in the stems of R. chinensis was negative, and biomass accumulation was significantly positively correlated with the dark respiration rate in stems, indicating that stem photosynthesis fixed CO2 released internally by respiration. This study reveals that stem photosynthesis in R. chinensis enhances biomass accumulation by promoting chlorophyll fluorescence and dark respiration rates in the stems. Furthermore, stem photosynthesis contributes to the balanced allocation of biomass by enhancing the proportional distribution of biomass to leaves and roots.

Key words: Stem photosynthesis, Biomass accumulation, CO2 refixation, Rosa chinensis, Chlorophyll concentration, Nonstructural carbohydrates