biostudies-literatureJin SNHLBI NIH HHSNIHNIGMS NIH HHS1274-85https://www.ebi.ac.uk/biostudies/studies/S-EPMC4247799biostudies-literatureUnknown12(9)The γ-tocopherol methyltransferase (γ-TMT) is an important enzyme regulating synthesis of four tocopherols (α, γ, β and δ). In this report, we investigated the role of γ-TMT in regulating abiotic stress within chloroplasts. The At γ-tmt overexpressed via the tobacco chloroplast genome accumulated up to 7.7% of the total leaf protein, resulting in massive proliferation of the inner envelope membrane (IEM, up to eight layers). Such high-level expression of γ-TMT converted most of γ-tocopherol to α-tocopherol in transplastomic seeds (~10-fold higher) in the absence of abiotic stress. When grown in 400 mm NaCl, α-tocopherol content in transplastomic TMT leaves increased up to 8.2-fold and 2.4-fold higher than wild-type leaves. Likewise, under heavy metal stress, α-tocopherol content in the TMTPlant biotechnology journalExpression of γ-tocopherol methyltransferase in chloroplasts results in massive proliferation of the inner envelope membrane and decreases susceptibility to salt and metal-induced oxidative stresses by reducing reactive oxygen species.PMC4247799R01 HL 109442R01 GM063879R01 HL 107904R01 GM 63879R01 HL109442R01 HL107904Jin SDaniell HfalseExpression of γ-tocopherol methyltransferase in chloroplasts results in massive proliferation of the inner envelope membrane and decreases susceptibility to salt and metal-induced oxidative stresses by reducing reactive oxygen species.The γ-tocopherol methyltransferase (γ-TMT) is an important enzyme regulating synthesis of four tocopherols (α, γ, β and δ). In this report, we investigated the role of γ-TMT in regulating abiotic stress within chloroplasts. The At γ-tmt overexpressed via the tobacco chloroplast genome accumulated up to 7.7% of the total leaf protein, resulting in massive proliferation of the inner envelope membrane (IEM, up to eight layers). Such high-level expression of γ-TMT converted most of γ-tocopherol to α-tocopherol in transplastomic seeds (~10-fold higher) in the absence of abiotic stress. When grown in 400 mm NaCl, α-tocopherol content in transplastomic TMT leaves increased up to 8.2-fold and 2.4-fold higher than wild-type leaves. Likewise, under heavy metal stress, α-tocopherol content in the TMT2014-01-01T00:00:00Z2014 Dec2025-04-19T23:09:45.197Z2019-03-27T01:40:29ZS-EPMC42477992505189810.1111/pbi.12224