Abstract
Isoprenoids in higher plants are produced independent two pathways, the MVA pathway in cytoplasm and the MEP pathway in plastids. The tapetum is characterized by the accumulation of lipid deposits in tapetosomes and elaioplasts. We tried to know the lipid components originated from whether the MVA or the MEP passway. The hmg1, defects HMGR in the MVA pathway, exhibited that tapetosomes and elaioplasts are morphological abnormality. The cla1, defects DXP synthetase of the MEP pathway, exhibited normal structure in tapetum. This result suggested that the elaioplasts lipids originate from the MVA pathway. The smt1, defects a sterol biosynthesis enzyme of downstream of the MVA pathway, exhibited some abnormality. The hs transgenic plant, the SMT2 overexpressor, showed normal structure, and the hc transgenic plant, the SMT2 co-suppressor, showed some abnormality. We expect that lipids of tapetosomes and elaioplasts originate from the MVA pathway, probably from the sterol biosynthesis pathway.
