title: Isolation, expression and evolution of FERTILIZATION INDEPENDENT ENDOSPERM homologs in Podostemaceae.
abstract: Podostemaceae is an interesting family of angiosperms with unusual development and morphology. Among these, double fertilization, a defining feature of angiosperms is invariably missing in the family. Consequently, embryo development in the seeds takes place without endosperm. In recent years, the role of polycomb genes has garnered much interest because of their crucial role in seed development. Some of these genes have been reported from many unrelated species, underlining their high conservation. Thus, it becomes exciting to know the role of these genes in podostemads, which are devoid of double fertilization and endosperm. Here, we report the isolation, characterization and expression patterns of homologs of Fertilization Independent Endosperm (FIE) in two species of Podostemaceae, Zeylanidium olivaceum and Polypleurum stylosum. FIE like homologs could be identified in Z. olivaceum (ZoFIE) and P. stylosum (PsFIE). The predicted amino acid sequence of FIE homologs showed similarity to other homologs, containing the conserved seven WD40 repeats. Expression studies revealed that ZoFIE and PsFIE transcripts were present in the vegetative tissue (thallus in Podostemaceae) and the seedlings, similar to the model plants. However, the ZoFIE and PsFIE expression disappeared in the flowering stages. This unique pattern of expression suggests that in the absence of double fertilization and endosperm the expression of FIS complex genes perhaps is obliterated in Podostemaceae.
authors.affiliation: Department of Botany, University of Delhi, Delhi, 110007, India.
authors.forename: Priyanka
authors.initials: P
authors.lastname: Khanduri
authors.affiliation: Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5A8, Canada.
authors.forename: Roopam
authors.initials: R
authors.lastname: Sharma
authors.affiliation: Department of Botany, University of Delhi, Delhi, 110007, India.
authors.forename: Vishnu
authors.initials: V
authors.lastname: Bhat
authors.affiliation: Department of Botany, University of Delhi, Delhi, 110007, India. rjtnd@rediffmail.com.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Tandon
mesh_terms: D000595:Amino Acid Sequence; D005075:Biological Evolution; D056625:Endosperm / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D019684:Magnoliopsida / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D054817:Pollination; D063146:Polycomb-Group Proteins / Q000235:genetics* / Q000378:metabolism; D012098:Reproduction; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D017422:Sequence Analysis, DNA
chemical_list: D010940:Plant Proteins; D063146:Polycomb-Group Proteins
keywords: Aquatic angiosperm; Fertilization Independent Endosperm; Homologs; Podostemaceae