The BAM1/BAM2 receptor-like kinases are important regulators of Arabidopsis early anther development.
Anther development involves the formation of several adjacent cell types required for normal male fertility. Only a few genes are known to be involved in early anther development, particularly in the establishment of these different cell layers. Arabidopsis thaliana BAM1 (for BARELY ANY MERISTEM) and BAM2 encode CLAVATA1-related Leu-rich repeat receptor-like kinases that appear to have redundant or overlapping functions. We characterized anther development in the bam1 bam2 flowers and found that bam1 bam2 anthers appear to be abnormal at a very early stage and lack the endothecium, middle, and tapetum layers. Analyses using molecular markers and cytological techniques of bam1 bam2 anthers revealed that cells interior to the epidermis acquire some characteristics of pollen mother cells (PMCs), suggesting defects in cell fate specification. The pollen mother-like cells degenerate before the completion of meiosis, suggesting that these cells are defective. In addition, the BAM1 and BAM2 expression pattern supports both an early role in promoting somatic cell fates and a subsequent function in the PMCs. Therefore, analysis of BAM1 and BAM2 revealed a cell-cell communication process important for early anther development, including aspects of cell division and differentiation. This finding may have implications for the evolution of multiple signaling pathways in specifying cell types for microsporogenesis.
Hord
Carey L H
CL
Department of Biology and the Huck Institutes for the Life Sciences, Pensylvania State University, University Park, Pensylvania 16802, USA.
Chen
Changbin
C
Deyoung
Brody J
BJ
Clark
Steven E
SE
Ma
Hong
H
D017360:Arabidopsis / Q000033:anatomy & histology / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D005075:Biological Evolution; D002454:Cell Differentiation; D002455:Cell Division / Q000502:physiology; D035264:Flowers / Q000254:growth & development* / Q000648:ultrastructure; D008540:Meiosis / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D011494:Protein Kinases / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology
D029681:Arabidopsis Proteins; D009687:Nuclear Proteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D012097:Repressor Proteins; C416221:SPL protein, Arabidopsis; C464786:At5g07280 protein, Arabidopsis; C519658:BAM1 protein, Arabidopsis; C519659:BAM2 protein, Arabidopsis