Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (9): 961-971.DOI: 10.17521/cjpe.2021.0240

• Research Articles • Previous Articles     Next Articles

Effects of non-structural carbohydrate and nitrogen allocation on the ability of Populus deltoides and P. cathayana to resist soil salinity stress

LIN Xia-Zhen1, LIU Lin2, DONG Ting-Ting2, FANG Qi-Bo2, GUO Qing-Xue2,*()   

  1. 1Teaching Center, Zhejiang Open University, Hangzhou 310012, China
    2College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China
  • Received:2021-06-28 Accepted:2021-08-11 Online:2021-09-20 Published:2021-11-18
  • Contact: GUO Qing-Xue


Aims The increasing level of soil salinization has been one of the most important factors to limit the development of forestry. The fast-growing Populusspp. are widely used for tree plantations and afforestation around the world and play crucial role in economic and ecological functions. Linking carbon and nitrogen metabolism with the resistance to soil salinity stress, will help to well develop the Populus plantations in salinization area.

Methods The present study used P. deltoidesand P. cathayana for materials, while two salt (NaCl) concentrations and two defoliation treatments were applied. The carbon supply ability and allocation, nitrogen metabolism and allocation of the two poplar species were mainly investigated in different treatments.

Important findings We found that the P. deltoides had higher total biomass and photosynthetic rate than P. cathayana under salinity stress. The chlorophyll concentration and the PSII maximum photochemical efficiency of P. deltoides were significantly higher than those of P. cathayana especially under defoliation with salinity stress, which demonstrated stronger damage on P. cathayana. The defoliation treatment aggravated the damage of NaCl on P. cathayana. The Na+ concentration in leaf and stem of P. deltoides was significantly lower than that of P. cathayana under salinity stress, demonstrating that the P. deltoides strongly restricted Na+ up-transport from root. Stem and root of P. deltoides had higher concentrations of starch, soluble sugars and sucrose than P. cathayana under salinity stress. The higher adenosine diphosphate glucose pyrophosphorylase activity facilitated the production of starch in P. deltoides than in P. cathayana. The defoliation greatly reduced the resistant ability of P. cathayana to salinity because of lower supply of non-structural carbohydrate to osmoregulation function. The allocation of nitrogen to sodium dodecyl sulfate-soluble protein of P. cathayana was significantly reduced by increasing salt, whereas NH4+ concentration, glutamate dehydrogenase activity and proline concentration were significantly higher than those of P. deltoides. Our results demonstrated the crucial role of non-structural carbohydrate of plant species in resisting soil salinity stress.

Key words: non-structural carbohydrate, osmoregulation, nitrogen allocation, Populus deltoides, Populus cathayana