Effect of exogenous calcium pretreatment on electron transport rate tomato seedlings under LNT.

<p>ETR(II), electron transport rate of PSII; ETR(I), electron transport rate of PSI. CK, the plant grown at optimal temperature, and used for control; CaCl₂+LNT, the plant pretreated with CaCl₂ and grown at low night temperature(LNT); H₂O+LNT, the plant pretreated with H₂O and grown at LNT; EGTA+LNT, the plant pretreated with EGTA and grown at LNT. Data are the means of four replicates with standard errors shown by vertical bars. *indicates significant difference (P≤0.05), and **indicates a highly significant difference (P≤0.01). Comparisons between the figures among all treatments under low night temperature are shown in parentheses.