Auxin flow in anther filaments is critical for pollen grain development through regulating pollen mitosis.
It was well known that auxin is critical for anther/pollen grain development, however, the clear distribution and detailed effects of auxin during floral development are still unclear. We have shown here that, through analyzing GUS activities of Arabidopsis lines harboring auxin response elements DR5-GUS, auxin was mainly accumulated in the anther during flower stages 10-12. Further studies employing the indoleacetic acid-lysine synthetase (iaaL) coding gene from Pseudomonas syringae subsp. savastanoi under control of the promoter region of Arabidopsis phosphatidylinositol monophosphate 5-kinase 1 gene, which conducts the anther filament-specific expression, showed that block of auxin flow of filaments resulted in shortened filaments and significantly defective pollen grains. Similar phenotype was observed in tobacco plants transformed with the same construct, confirming the effects of auxin flow in filaments on anther development. Detailed studies further revealed that the meiosis process of pollen grain was normal while the mitosis at later stage was significantly defected, indicating the effects of auxin flow in filaments on pollen grain mitosis process. Analysis employing [(14)C]IAA, as well as the observation on the expression of AtPIN1, coding for auxin efflux carrier, demonstrated the presence of polar auxin transport in anther filaments and pollen grains.
Feng
Xiao-Li
XL
National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology, Shanghai Institutes for Biological Sciences/SIBS, Chinese Academy of Sciences, PR China.
Ni
Wei-Min
WM
Elge
Stephan
S
Mueller-Roeber
Bernd
B
Xu
Zhi-Hong
ZH
Xue
Hong-Wei
HW
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D035264:Flowers / Q000033:anatomy & histology / Q000254:growth & development; D005966:Glucuronidase / Q000032:analysis; D007210:Indoleacetic Acids / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism; D008938:Mitosis / Q000502:physiology*; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000254:growth & development / Q000378:metabolism; D011058:Pollen / Q000033:anatomy & histology / Q000166:cytology / Q000254:growth & development*; D011401:Promoter Regions, Genetic; D044224:Pseudomonas syringae / Q000201:enzymology / Q000235:genetics
D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; C116363:PIN1 protein, Arabidopsis; D005966:Glucuronidase; D010453:Peptide Synthases; C048911:indoleacetic acid-lysine synthetase