Communication between the Maternal Testa and the Embryo and/or Endosperm Affect Testa Attributes in Tomato

Authors

A. Bruce Downie, University of Kentucky
Deqing Zhang, University of Kentucky
Lynnette M. A. Dirk, University of Kentucky
Richard R. Thacker, University of Kentucky
Janet A. Pfeiffer, University of Kentucky
Jennifer L. Drake, University of Kentucky
Avraham A. Levy, Weizmann Institute of Science, Israel
D. Allan Butterfield, University of Kentucky
Jack W. Buxton, University of Kentucky
John C. Snyder, University of Kentucky

Abstract

Two tomato (Lycopersicon esculentum) mutants with dark testae displaying poor germination rate and percentage on both water and 100 μM gibberellin_{4 + 7} were recovered. The mutants were allelic (black seed1-1; bks1-1 and bks1-2), inherited in Mendelian fashion as a recessive gene residing on chromosome 11. They are not allelic to bs (brown seed) -1, -2, or -4, which impair seed germination and possess dark testae. The bks/bs mutants accumulated dark pigment in the cell layers of the testa above the endothelium, which itself accumulated proanthocyanidins similar to wild type. The poor germination performance of bks mutant seeds was because of impediment of the mutant testae to radicle egress. Imbibition on gibberellin_{4 + 7} did not ameliorate germination percentage or rate. The toughening of the bks testa and associated poor germination were partially overcome when seeds were not dried before germination or were dried under N₂. The seeds of the bks mutant have elevated activity of at least one enzyme responsible for the detoxification of reactive oxygen species. The bks mutant is epistatic to 12 anthocyaninless mutants of tomato. Bio- and physicochemical analysis of the bks testa determined that it accumulated a melanic substance. Inheritance of bks/bs mutations contrasts with that of the anthocyaninless mutants, which are inherited according to the genotype of the maternally derived testa. This suggests that the testa manufactures components before its demise that can maximize testa strength, whereas the endosperm/embryo produces factors that are conveyed to the testa, mitigating this process.

Document Type

Article

Publication Date

9-2003

Notes/Citation Information

Published in Plant Physiology, v. 133, no. 1, p. 145-160.

© 2003 American Society of Plant Biologists

Digital Object Identifier (DOI)

https:/​/​doi.​org/​10.​1104/​pp.​103.​022632

Repository Citation

Downie, A. Bruce; Zhang, Deqing; Dirk, Lynnette M. A.; Thacker, Richard R.; Pfeiffer, Janet A.; Drake, Jennifer L.; Levy, Avraham A.; Butterfield, D. Allan; Buxton, Jack W.; and Snyder, John C., "Communication between the Maternal Testa and the Embryo and/or Endosperm Affect Testa Attributes in Tomato" (2003). Horticulture Faculty Publications. 11.
https://uknowledge.uky.edu/horticulture_facpub/11