Proteomic analysis of lettuce seed germination and thermoinhibition by sampling of individual seeds at germination and removal of storage proteins by polyethylene glycol fractionation.
Germination and thermoinhibition in lettuce (Lactuca sativa 'Jianyexianfeng No. 1') seeds were investigated by a proteomic comparison among dry seeds, germinated seeds at 15°C, at 15°C after imbibition at 25°C for 48 h, or at 25°C in KNO3 (all sampled individually at germination), and ungerminated seeds at 25°C, a thermoinhibitory temperature. Before two-dimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two-dimensional gels. A total of 108 protein spots were identified to change more than 2-fold (P<0.05) in abundance in at least one germination treatment. Nineteen proteins increasing and one protein decreasing in abundance during germination had higher abundance in germinated 15°C, 15°C after imbibition at 25°C for 48 h, and 25°C in KNO3 seeds than in ungerminated 25°C seeds. Gene expression of 12 of those proteins correlated well with the protein accumulation. Methionine metabolism, ethylene production, lipid mobilization, cell elongation, and detoxification of aldehydes were revealed to be potentially related to lettuce seed germination and thermoinhibition. Accumulation of three proteins and expression of five genes participating in the mevalonate (MVA) pathway of isoprenoid biosynthesis correlated positively with seed germinability. Inhibition of this pathway by lovastatin delayed seed germination and increased the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination and thermoinhibition.
Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (W.-Q.W., B.-Y.S., Z.-J.D., Y.W., S.-J.L., S.-Q.S.);College of Biology Resources and Environmental Sciences, Jishou University, Jishou 416000, China (B.-Y.S.);College of Forestry and Horticulture, Hubei Minzu University, Enshi 445000, China (Z.-J.D.); andDepartment of Molecular Biology and Genetics, Aarhus University, Flakkebjerg, DK-4200 Slagelse, Denmark (I.M.M.).
Wei-Qing
http://orcid.org/0000-0003-0174-9905
WQ
Wang
Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (W.-Q.W., B.-Y.S., Z.-J.D., Y.W., S.-J.L., S.-Q.S.);College of Biology Resources and Environmental Sciences, Jishou University, Jishou 416000, China (B.-Y.S.);College of Forestry and Horticulture, Hubei Minzu University, Enshi 445000, China (Z.-J.D.); andDepartment of Molecular Biology and Genetics, Aarhus University, Flakkebjerg, DK-4200 Slagelse, Denmark (I.M.M.).
Bin-Yan
BY
Song
Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (W.-Q.W., B.-Y.S., Z.-J.D., Y.W., S.-J.L., S.-Q.S.);College of Biology Resources and Environmental Sciences, Jishou University, Jishou 416000, China (B.-Y.S.);College of Forestry and Horticulture, Hubei Minzu University, Enshi 445000, China (Z.-J.D.); andDepartment of Molecular Biology and Genetics, Aarhus University, Flakkebjerg, DK-4200 Slagelse, Denmark (I.M.M.).
Zhi-Jun
ZJ
Deng
Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (W.-Q.W., B.-Y.S., Z.-J.D., Y.W., S.-J.L., S.-Q.S.);College of Biology Resources and Environmental Sciences, Jishou University, Jishou 416000, China (B.-Y.S.);College of Forestry and Horticulture, Hubei Minzu University, Enshi 445000, China (Z.-J.D.); andDepartment of Molecular Biology and Genetics, Aarhus University, Flakkebjerg, DK-4200 Slagelse, Denmark (I.M.M.).
Yue
Y
Wang
Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (W.-Q.W., B.-Y.S., Z.-J.D., Y.W., S.-J.L., S.-Q.S.);College of Biology Resources and Environmental Sciences, Jishou University, Jishou 416000, China (B.-Y.S.);College of Forestry and Horticulture, Hubei Minzu University, Enshi 445000, China (Z.-J.D.); andDepartment of Molecular Biology and Genetics, Aarhus University, Flakkebjerg, DK-4200 Slagelse, Denmark (I.M.M.).
Shu-Jun
SJ
Liu
Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (W.-Q.W., B.-Y.S., Z.-J.D., Y.W., S.-J.L., S.-Q.S.);College of Biology Resources and Environmental Sciences, Jishou University, Jishou 416000, China (B.-Y.S.);College of Forestry and Horticulture, Hubei Minzu University, Enshi 445000, China (Z.-J.D.); andDepartment of Molecular Biology and Genetics, Aarhus University, Flakkebjerg, DK-4200 Slagelse, Denmark (I.M.M.).
Ian Max
IM
Møller
Key Laboratory of Plant Resources and Beijing Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (W.-Q.W., B.-Y.S., Z.-J.D., Y.W., S.-J.L., S.-Q.S.);College of Biology Resources and Environmental Sciences, Jishou University, Jishou 416000, China (B.-Y.S.);College of Forestry and Horticulture, Hubei Minzu University, Enshi 445000, China (Z.-J.D.); andDepartment of Molecular Biology and Genetics, Aarhus University, Flakkebjerg, DK-4200 Slagelse, Denmark (I.M.M.) sqsong@ibcas.ac.cn.
Song-Quan
SQ
Song
D000040:Abscisic Acid / Q000378:metabolism; D053898:Biosynthetic Pathways; D005591:Chemical Fractionation; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D018525:Germination; D018545:Lactuca / Q000235:genetics / Q000378:metabolism*; D008798:Mevalonic Acid / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011092:Polyethylene Glycols; D040901:Proteomics; D055314:Seed Storage Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000378:metabolism*; D013696:Temperature; D013729:Terpenes / Q000378:metabolism
D005030:Ethylenes; D010937:Plant Growth Regulators; D010940:Plant Proteins; D055314:Seed Storage Proteins; D013729:Terpenes; D011092:Polyethylene Glycols; D000040:Abscisic Acid; C036216:ethylene; D008798:Mevalonic Acid