Overexpression of TAPETUM DETERMINANT1 alters the cell fates in the Arabidopsis carpel and tapetum via genetic interaction with excess microsporocytes1/extra sporogenous cells.
Previously, we reported that the TAPETUM DETERMINANT1 (TPD1) gene is required for specialization of tapetal cells in the Arabidopsis (Arabidopsis thaliana) anther. The tpd1 mutant is phenotypically identical to the excess microsporocytes1 (ems1)/extra sporogenous cells (exs) mutant. The TPD1 and EMS1/EXS genes may function in the same developmental pathway in the Arabidopsis anther. Here, we further report that overexpression of TPD1 alters the cell fates in the Arabidopsis carpel and tapetum. When TPD1 was expressed ectopically in the wild-type Arabidopsis carpel, the number of cells in the carpel increased significantly, showing that the ectopic expression of TPD1 protein could activate the cell division in the carpel. Furthermore, the genetic analysis showed that the activation of cell division in the transgenic carpel by TPD1 was dependent on EMS1/EXS, as it did not happen in the ems1/exs mutant. This result further suggests that TPD1 regulates cell fates in coordination with EMS1/EXS. Moreover, overexpression of TPD1 in tapetal cells also delayed the degeneration of tapetum. The TPD1 may function not only in the specialization of tapetal cells but also in the maintenance of tapetal cell fate.
Yang
Shu-Lan
SL
Institute of Molecular and Cell Biology, Singapore.
Jiang
Lixi
L
Puah
Ching San
CS
Xie
Li-Fen
LF
Zhang
Xue-Qin
XQ
Chen
Li-Qun
LQ
Yang
Wei-Cai
WC
Ye
De
D
D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002455:Cell Division; D035264:Flowers / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009154:Mutation; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*
D029681:Arabidopsis Proteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; C483722:Tapetum determinant1 protein, Arabidopsis; C464786:At5g07280 protein, Arabidopsis