Figure 6.

Correlation between Ca²⁺-ATPase activity and pollen germination rate or pollen tube length. (A) Reciprocal effect of ALA on pollen Ca²⁺-ATPase activity. Pollens were evenly placed in petri dishes containing basal medium alone, or with 10 mg/L ALA, 10 mg/L ALA + 10⁻³ M Ca²⁺, 10 mg/L ALA + 10⁻³ M Ca²⁺ + 10⁻³ M EGTA, and incubated at 25°C at 100% humidity, in the dark for 3 h. Then Ca²⁺-ATPase activity was assayed using the Ca²⁺-ATPase assay kit. (B) Negative correlation between Ca²⁺-ATPase activity and pollen germination rate (B₁) or pollen tube length (B₂). Pollens were evenly placed in petri dishes containing basal medium alone, or with 10 mg/L ALA, 10 mg/L ALA + 10⁻⁵ M Ca²⁺, 10 mg/L ALA + 10⁻⁴ M Ca²⁺, 10 mg/L ALA + 10⁻³ M Ca²⁺, 10 mg/L ALA + 10⁻³ M Ca²⁺ + 10⁻³ M EGTA, and incubated at 25°C at 100% humidity, in the dark for 3 h. Then pollen germination rate, pollen tube length, and Ca²⁺-ATPase activity were determined and correlation analysis between them were carried out. Values are the means of 9 measurements ± SE from three independent experiments.