Chin J Plant Ecol ›› 2023, Vol. 47 ›› Issue (3): 374-388.DOI: 10.17521/cjpe.2022.0032

Special Issue: 光合作用

• Research Articles • Previous Articles     Next Articles

Regulation of exogenous hydrogen sulfide on photosynthetic carbon metabolism in Avena nude under saline-alkaline stress

LIU Jian-Xin(), LIU Rui-Rui, LIU Xiu-Li, JIA Hai-Yan, BU Ting, LI Na   

  1. Gansu Key Laboratory of Protection and Utilization for Biological Resources and Ecological Restoration; College of Life Sciences and Technology, Longdong University, Qingyang, Gansu 745000, China
  • Received:2022-01-19 Accepted:2022-07-06 Online:2023-03-20 Published:2022-07-15
  • Contact: LIU Jian-Xin
  • Supported by:
    National Natural Science Foundation of China(31960375);Natural Science Foundation of Gansu Province(20JR5RA491)

Abstract:

Aims The purpose of this study was to investigate the regulatory effect of exogenous H2S on the photosynthetic carbon metabolism of plants under saline-alkali stress.

Methods The Avena nude was selected and a potted soil culture experiment was conducted to study the effects of spraying 50 µmol·L−1 H2S donor sodium hydrosulfide (NaHS) solution on photosynthetic and fluorescence parameters, the contents of monosaccharides, oligosaccharides and starch, the activities of key enzymes in Calvin cycle and sugar metabolism in leaves, and yield components under 3.00 g·kg-1 saline-alkali stress.

Important findings (1) Spraying NaHS significantly decreased chlorophyll content, intercellular CO2 concentration, photosystem II (PSII) initial fluorescence, maximum fluorescence, regulatory energy dissipation, photochemical quenching, non-photochemical quenching, and significantly increased Hill reaction activity, net photosynthetic rate, transpiration rate, stomatal conductance, apparent CO2 utility efficiency, PSII maximum photochemical efficiency, and the activities of ribulose-1,5-bisphophate carboxylase (Rubisco), Rubisco activase, glyceraldehyde-3-phosphate dehydrogenase and transketolase in A. nude leaves under salt-alkali stress. These indicated that exogenous H2S could alleviate saline-alkali stress-induced photoinhibition and photosynthetic rate decrease by reducing light energy absorption and the portion of light energy absorbed by the PSII antenna pigment which was used for photochemical electron transfer, improving primary photochemical efficiency and promoting water photolysis of PSII, regulating key enzyme activities in the Calvin cycle, and enhancing CO2 utility efficiency. (2) Under saline-alkali stress, the activities of α-amylase and sucrose phosphate synthase were significantly increased and the contents of starch and reducing sugar and neutral invertase activities were significantly decreased in A. nude leaves on the 7th day after spraying NaHS. On the 14th day, the contents of total soluble sugar and reducing sugar, and the activities of sucrose synthase and sucrose phosphate synthase decreased significantly, and the activity of neutral invertase increased significantly. The contents of glucose, fructose and galactose on the 7th and 14th days increased to varying degrees, and the content of raffinose decreased significantly, while the activities of total amylase, β-amylase, starch phosphorylase, adenosine diphosphate glucose pyrophosphorylase and acid invertase and the contents of fucose, trehalose and sucrose did not change significantly. These changes suggested that exogenous H2S was involved in the regulation of starch and sucrose metabolism and the conversion between polysaccharides and oligosaccharides in A. nude under saline-alkali stress. (3) Spraying NaHS had no significant effect on plant height, spike numbers per plant, boll numbers per spike, thousand-grain weight and biological yield per plant of A. nude under salt-alkali stress, while grain numbers per spike and grain yield per plant were increased significantly. In summary, exogenous H2S participates in the regulation of photosynthetic carbon metabolism in A. nude under salt-alkali stress, and it can enhance the tolerance of A. nude to saline-alkali stress.

Key words: hydrogen sulfide, Avena nude, saline-alkali stress, photosynthetic parameter, fluorescence parameter, carbon metabolism, yield component