physical, enzymatic, and genetic characterization of perturbations in the seeds of the brownseed tomato mutants

• Published in: Journal of experimental botany 2004-05, Vol.55 (399), p.961-973
• Main Authors: Downie, A.B, Dirk, L.M.A, Xu, Q, Drake, J, Zhang, D, Dutt, M, Butterfield, A, Geneve, R.R, Corum, J.W. III, Lindstrom, K.G
• Format: Article
• Language: English
• Subjects: Anthocyanins - genetics; Biological and medical sciences; Catalase; Developmental biology; electron paramagnetic resonance (EPR); Enzymes; Expressed Sequence Tags; free radicals; Fruits; Fundamental and applied biological sciences. Psychology; Genotypes; Germination; Imbibition; Kinetics; Libraries; Lycopersicon esculentum; Lycopersicon esculentum - genetics; Lycopersicon esculentum - physiology; macro‐array; Messenger RNA; Metabolism; Mutation; Nucleic Acid Hybridization; peroxidase; Plant physiology and development; Reactive oxygen species; Research Papers: Cell and Molecular Biology, Biochemistry and Molecular Physiology; seed; Seeds; Seeds - physiology; subtractive‐suppressive PCR; Testa
• ISSN: 0022-0957; 1460-2431; 1460-2431
• DOI: 10.1093/jxb/erh112

The brownseed mutants (bs1, bs2, and bs4) of tomato all possess dark testae and deleteriously affect seed germination speed and/or final percentage. Poor germination performance of the bs1 but not the bs4 mutant, was due to greater impediment to radicle egress. Testa toughening (bs1) was prevented by drying in N2. However, poor germination speed was hardly affected by drying. GA(4+7) did not ameliorate germination percentage or speed (bs1, bs2), whereas bs4 seeds commenced radicle protrusion sooner and had a greater germination percentage. bs1 mutant seeds have two times more catalase activity while those of bs4 contained six times more peroxidase and almost two times more catalase activity than WTs. bs4 release only half of the reactive oxygen species into the media than WT during imbibition. EPR detected the presence of free radicals in bs1 and its WT. bs mutants were epistatic to 12 anthocyaninless mutations, at least some of which produce seeds of lighter than usual testa colour. Macro-arrays of subtractive, suppressive PCR products identified differentially regulated transcripts between seeds of bs4 and WT. EST identity suggests bs4 does not exit the developmental programme upon attaining maturity.