the effect of acid rain of seedings

This is a biological question, placing it in biology discussion group will be better.
Reason (1) When seed is germinating, it imbibes water through the testa. Once water is presence, an hormone called gibberellins (GAs) will be secreted from the embryo. GAs will then be translocated to the aleurone layer. GAs makes this layer form an enzyme, amylase, to digest the stored food - starch in the endosperm. The amylase converts starch to maltose and then to glucose which will finially be transported to support the growth of growing points of the seed such as shoot ,root and leaves. Since enzyme, amylase, is pH sensitive, any acidic medium will affect its work. Hence the growth of the shoot from plumule , root from radicle and plant tissue such as chlorophyll of leaves will be hindered.
Reason (2). When rain becomes acidic such as due to the burning of coal, dilute sulphuric acid will be formed. When H2SO4 is dissolved in water, it undergoes dissoication. Eqt: H2SO4 + H2O →H3O+ + HSO4-. And HSO4- + H2O →H3O+ + SO42-. If seed requires calcium ion to grow, it can't get it. This is because the calcium ions will form an insoluble product with sulphate ions. Ca2+(aq)+SO42- (aq)→CaSO4(s). Acid rain hinders the absorption of ions from water by root hair of the plants.
I hope you will find them helpful.