TY  - JOUR
A1  - Feng, Xiao-Li
A1  - Ni, Wei-Min
A1  - Elge, Stephan
A1  - Müller-Röber, Bernd
A1  - Xu, Zhi-Hong
A1  - Xue, Hong-Wei
T1  - Auxin flow in anther filaments is critical for pollen grain development through regulating pollen mitosis
N2  - 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 [C-14]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
Y1  - 2006
UR  - http://www.springerlink.com/content/100330
U6  - https://doi.org/10.1007/s11103-006-0005-z
SN  - 0167-4412
ER  - 
TY  - GEN
A1  - Lou, Ying
A1  - Ma, Hui
A1  - Lin, Wen-Hui
A1  - Chu, Zhao-Quing
A1  - Müller-Röber, Bernd
A1  - Xu, Zhi-Hong
A1  - Xue, Hong-Wei
T1  - The highly charged region of plant beta-type phosphatidylinositol 4-kinase is involved in membrane targeting and phospholipid binding
N2  - In Arabidopsis thaliana and Oryza sativa, two types of PI 4-kinase (PI4Ks) have been isolated and functionally characterized. The alpha-type PI4Ks (similar to 220 kDa) contain a PH domain, which is lacking in beta-type PI4Ks (similar to 120 kDa). beta-Type PI4Ks, exemplified by Arabidopsis AtPI4K beta and rice OsPI4K2, contain a highly charged repetitive segment designated PPC (Plant PI4K Charged) region, which is an unique domain only found in plant beta-type PI4Ks at present. The PPC region has a length of similar to 300 amino acids and harboring 11 (AtPI4K beta) and 14 (OsPI4K2) repeats, respectively, of a 20-aa motif. Studies employing a modified yeast-based "Sequence of Membrane- Targeting Detection'' system demonstrate that the PPC(OsPI4K2) region, as well as the former 8 and latter 6 repetitive motifs within the PPC region, are able to target fusion proteins to the plasma membrane. Further detection on the transiently expressed GFP fusion proteins in onion epidermal cells showed that the PPC(OsPI4K2) region alone, as well as the region containing repetitive motifs 1-8, was able to direct GFP to the plasma membrane, while the regions containing less repetitive motifs, i.e. 6, 4, 2 or single motif(s) led to predominantly intracellular localization. Agrobacterium-mediated transient expression of PPC-GFP fusion protein further confirms the membrane-targeting capacities of PPC region. In addition, the predominant plasma membrane localization of AtPI4Kb was mediated by the PPC region. Recombinant PPC peptide, expressed in E. coli, strongly binds phosphatidic acid, PI and PI4P, but not phosphatidylcholine, PI5P, or PI(4,5) P-2 in vitro, providing insights into potential mechanisms for regulating sub- cellular localization and lipid binding for the plant beta-type PI4Ks
Y1  - 2006
UR  - http://www.springerlink.com/content/100330
U6  - https://doi.org/10.1007/s11103-005-5548-x
SN  - 0167-4412
ER  -