Sorghum variety Longza 17 was used as the experimental organism in a study of the effects of different types of sodium salt (two neutral salts, NaCl and Na₂SO₄; and two alkaline salts, NaHCO₃ and Na₂CO₃), at an equivalent Na⁺ concentration (100 mmol·L⁻¹) on leaf growth parameters and PSII and PSI function by using the Fast Chlorophyll Fluorescence Induction Dynamics technique and 820 nm light reflectance curves. The results showed that at Na⁺ concentration of 100 mmol·L⁻¹, different types of sodium salt stress significantly inhibited the growth of sorghum plants. Different types of sodium salt stress showed significant inhibition on the activities of PSII and PSI in sorghum leaves, the impact of different types of sodium salt on the activities of PSII and PSI in sorghum leaves was consistent, listed from greatest to least impact as Na₂CO₃ > NaHCO₃ > Na₂SO₄ > NaCl. The effects of alkaline salt stress on the growth and photosynthetic properties of sorghum were greater than those under the neutral salt stress, therefore, in addition to considering the impact of Na⁺ concentration in the sorghum planting area, emphasis should also be given to the influence of the degree of alkalization, especially the higher alkalinity of Na₂CO₃.

Drought stress led to a decrease in PSII photochemical activity in tobacco leaves and the blockage of electron transfer, especially from Q_A to Q_B on PSII acceptor side. In addition, drought stress caused a dramatic increase in H₂O₂ and MDA contents. However, the overexpression of 2-Cys Prx significantly reduced the H₂O₂ accumulation in tobacco seedlings and alleviated the degree of oxidative damage under drought stress. It also improved stomatal limitation and net photosynthetic rate of tobacco seedlings and reduced its PSII photoinhibition under drought stress which promoted the ability of PSII electron transfer.