RT Journal Article
SR Electronic
T1 Nucleus- and plastid-targeted annexin 5 promotes reproductive development in Arabidopsis and is essential for pollen and embryo formation
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 331249
DO 10.1101/331249
A1 Malgorzata Lichocka
A1 Wojciech Rymaszewski
A1 Karolina Morgiewicz
A1 Izabela Barymow-Filoniuk
A1 Aleksander Chlebowski
A1 Miroslaw Sobczak
A1 Marcus A. Samuel
A1 Elmon Schmelzer
A1 Magdalena Krzymowska
A1 Jacek Hennig
YR 2018
UL http://biorxiv.org/content/early/2018/05/25/331249.abstract
AB Background Pollen development is a strictly controlled post-meiotic process during which microspores differentiate into microgametophytes and profound structural and functional changes occur in organelles. Annexin 5 is a calcium- and lipid-binding protein that is highly expressed in pollen grains and regulates pollen development and physiology. To gain further insights into the role of ANN5 in Arabidopsis development, we performed detailed phenotypic characterization of Arabidopsis plants with modified ANN5 levels. In addition, interaction partners and subcellular localization of ANN5 were analyzed to investigate potential functions of ANN5 at cellular level.Results Here, we report that RNAi-mediated suppression of ANN5 results in formation of smaller pollen grains, enhanced pollen lethality, and delayed pollen tube growth. ANN5 RNAi knockdown plants also displayed aberrant development during the transition from the vegetative to generative phase and during embryogenesis, reflected by delayed bolting time and reduced embryo size, respectively. At the subcellular level, ANN5 was delivered to the nucleus, nucleolus, and cytoplasm, and was frequently localized in plastid nucleoids, suggesting a likely role in interorganellar communication. Furthermore, ANN5-YFP co-immunoprecipitated with RABE1b, a putative GTPase, and interaction in planta was confirmed in plastidial nucleoids using FLIM-FRET analysis.Conclusions Our findings let us to propose that ANN5 influences basal cell homeostasis via modulation of plastid activity during pollen maturation. We hypothesize that the role of ANN5 is to orchestrate the plastidial and nuclear genome activities via protein-protein interactions however not only in maturing pollen but also during the transition from the vegetative to the generative growth and embryo development.AbbreviationsFLIM-FRETFluorescence Lifetime Imaging Microscopy-Förster Resonance Energy Transferldlong dayOEoverexpressionPCAprincipal component analysisRNAiRNA interferencesdshort daySDstandard deviationVCvegetative cell