Abolition of the tapetum suicide program ruins microsporogenesis.
Microsporogenesis in angiosperms takes places within the anther. Microspores are surrounded by a layer of cells, the tapetum, which degenerates during the later stages of pollen development with cytological features characteristic of programmed cell death (PCD). We report herein that the expression of AtBI-1, which suppresses Bax-induced cell death, in the tapetum at the tetrad stage inhibits tapetum degeneration and subsequently results in pollen abortion, while activation of AtBI-1 at the later stage does not. Our results demonstrate that the PCD signal commences at the tetrad stage and that the proper timing of PCD in the tapetum is essential for normal microsporogenesis.
Kawanabe
Takahiro
T
Laboratory of Environmental Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555 Japan.
Ariizumi
Tohru
T
Kawai-Yamada
Maki
M
Uchimiya
Hirofumi
H
Toriyama
Kinya
K
D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000502:physiology; D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000502:physiology; D017343:Genes, Plant / Q000235:genetics; D020287:In Situ Nick-End Labeling; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology; D051379:Mice; D011058:Pollen / Q000166:cytology* / Q000254:growth & development* / Q000502:physiology; D013997:Time Factors; D051028:bcl-2-Associated X Protein / Q000494:pharmacology
C491862:ATBI-1 protein, Arabidopsis; D051017:Apoptosis Regulatory Proteins; D029681:Arabidopsis Proteins; D008565:Membrane Proteins; C483722:Tapetum determinant1 protein, Arabidopsis; D051028:bcl-2-Associated X Protein