Study On Substance Metabolism Changes In Endosperm Of Tilia Miqueliana Seeds During Dormancy Releasing

Substance metabolism changes were studied by measuring the changes of respiration metabolism, the stored substances contents, hydrolysis enzymes activities, and endogenous hormone contents in endosperm of Tilia miqueliana seeds during dormancy releasing,the results were showed as follows:1. The moisture contents and respiratory intensity rose slowly of Tilia miqueliana seeds without treatment during stratification 75 days. The PGI activities rose , but the MDH and G-6-PDH+6-PGDH activities kept steady,which indicated that the respiration did not change obviously.The stored substances were utilized a few.The contents of soluble sugar, soluble protein and fat declined slowly,but the free amino acids and starch increased in the endosperm of Tilia miqueliana seeds without treatment.The activities of amylase,β-amylase, proteinase and acid phosphoesterase increased gradually,but the activities ofα-amylase reduced. The contents of GA3,ZR and ABA were not obviousle change.2. The moisture contents and respiratory intensity increased, and the G-6-PDH+6-PGDH activities increased,but the PGI and MDH activities increased at first then decreased,which indicated the activation of TCA and PPP pathway was the key factor to dormancy releasing of Tilia miqueliana seeds with soaking by 98% sulphuric acid(H2SO4) and GA3. The contents of soluble sugar, soluble protein,free amino acids,starch and fat in endosperm of Tilia miqueliana seeds with soaking by 98% sulphuric acid(H2SO4)and GA3 increased at first then declined,which indicated that the storage materials were utilized gradually. The metabolism of endosperm was enhanced, and the activities of amylase,α,β-amylase, proteinase and acid phosphoesterase increased. The contents of GA3,ZR and ABA declinded obviously, which indicated abrupt changes of endogenous hormones had a positive effect to release dormancy and germinate for Tilia miqueliana seeds.3. The activities of amylase,αandβ-amylase of Tilia miqueliana seeds with soaking by concentrated H2SO4 increased as a whole ,and the higher than the untreatment,which indicated that the activities of amylase,αandβ-amylase could be enhanced with GA3.