Fig. 2

Effects of exogenous GR24 on the gas exchange parameters Pn (A), Gs (B), Ci (C) and Tr (D) in cucumber seedlings under low light stress. Note: The respective parameters were measured at 0, 1, 4, and 7 days after the start of low light stress and/or 10 μM GR24 treatments. Each histogram represents the mean value of three independent experiments, and the vertical bars indicate SEs (n = 3). Different letters indicate significant differences at P < 0.05, according to Duncan’s multiple range tests. Cont, 0 μM GR24 + 500 μmolm^− 2 s^− 1 PPFD; Cont+GR24, 10 μM GR24 + 500 μmolm^− 2 s^− 1 PPFD; LL, 0 μM GR24 + 60 μmolm^− 2 s^− 1 PPFD; LL + GR24, 10 μM GR24 + 60 μmolm^− 2 s^− 1 PPFD. Here, Pn, net photosynthetic rate; Gs, stomatal conductance; Ci, intercellular CO₂ concentration; Tr, transpiration rate