title: PwHAP5, a CCAAT-binding transcription factor, interacts with PwFKBP12 and plays a role in pollen tube growth orientation in Picea wilsonii.
abstract: The HAP complex occurs in many eukaryotic organisms and is involved in multiple physiological processes. Here it was found that in Picea wilsonii, HAP5 (PwHAP5), a putative CCAAT-binding transcription factor gene, is involved in pollen tube development and control of tube orientation. Quantitative real-time reverse transcription-PCR showed that PwHAP5 transcripts were expressed strongly in germinating pollen and could be induced by Ca(2+). Overexpression of PwHAP5 in pollen altered pollen tube orientation, whereas the tube with PwHAP5RNAi showed normal growth without diminishing pollen tube growth. Furthermore, PwFKBP12, which encodes an FK506-binding protein (FKBP) was screened and a bimolecular fluorescence complementation assay performed to confirm the interaction of PwHAP5 and PwFKBP12 in vivo. Transient expression of PwFKBP12 in pollen showed normal pollen tube growth, whereas the tube with PwFKBP12RNAi bent. The phenotype of overexpression of HAP5 on pollen tube was restored by FKBP12. Altogether, our study supported the role of HAP5 in pollen tube development and orientation regulation and identified FKBP12 as a novel partner to interact with HAP5 involved in the process.
authors.affiliation: Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, PR China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Yu
authors.forename: Yanze
authors.initials: Y
authors.lastname: Li
authors.forename: Guixue
authors.initials: G
authors.lastname: Huang
authors.forename: Zhaodong
authors.initials: Z
authors.lastname: Meng
authors.forename: Dun
authors.initials: D
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Wei
authors.forename: Kang
authors.initials: K
authors.lastname: Yan
authors.forename: Chengchao
authors.initials: C
authors.lastname: Zheng
authors.forename: Lingyun
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D023081:CCAAT-Binding Factor / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D028222:Picea / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D010940:Plant Proteins; D053205:Pollen Tube / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D011485:Protein Binding; D016415:Sequence Alignment; D022061:Tacrolimus Binding Protein 1A / Q000235:genetics / Q000378:metabolism*
chemical_list: D023081:CCAAT-Binding Factor; D010940:Plant Proteins; D022061:Tacrolimus Binding Protein 1A