Fig. 4

Changes of Pro in lithophytic bryophytes in different calcium environments. A The changes of Pro content of three lithophytic bryophytes cultured in different concentrations of Ca²⁺ solution for 7 days. B The change of Pro content of three lithophytic bryophytes after 7 days in Ca²⁺ 50 mmol/L solution. C The change of Pro content of three lithophytic bryophytes after 7 days in Ca²⁺ 100 mmol/L solution. D The change of Pro content of three lithophytic bryophytes after 7 days in Ca²⁺ 200 mmol/L solution. E The change of Pro content of three lithophytic bryophytes after 7 days in Ca²⁺ 400 mmol/L solution. F Changes in Pro content of three lithophytic bryophytes after 7 days of cultivation in Ca²⁺ 800 mmol/L solution