@article{liu_franks_feng_liu_fu_(jenny) xiang_2013, title={Characterization of the sequence and expression pattern of LFY homologues from dogwood species (Cornus) with divergent inflorescence architectures}, volume={112}, ISSN={0305-7364, 1095-8290}, url={https://academic.oup.com/aob/article-lookup/doi/10.1093/aob/mct202}, DOI={10.1093/aob/mct202}, abstractNote={BACKGROUND AND AIMS
LFY homologues encode transcription factors that regulate the transition from vegetative to reproductive growth in flowering plants and have been shown to control inflorescence patterning in model species. This study investigated the expression patterns of LFY homologues within the diverse inflorescence types (head-like, umbel-like and inflorescences with elongated internodes) in closely related lineages in the dogwood genus (Cornus s.l.). The study sought to determine whether LFY homologues in Cornus species are expressed during floral and inflorescence development and if the pattern of expression is consistent with a function in regulating floral development and inflorescence architectures in the genus.


METHODS
Total RNAs were extracted using the CTAB method and the first-strand cDNA was synthesized using the SuperScript III first-strand synthesis system kit (Invitrogen). Expression of CorLFY was investigated by RT-PCR and RNA in situ hybridization. Phylogenetic analyses were conducted using the maximum likelihood methods implemented in RAxML-HPC v7.2.8.


KEY RESULTS
cDNA clones of LFY homologues (designated CorLFY) were isolated from six Cornus species bearing different types of inflorescence. CorLFY cDNAs were predicted to encode proteins of approximately 375 amino acids. The detection of CorLFY expression patterns using in situ RNA hybridization demonstrated the expression of CorLFY within the inflorescence meristems, inflorescence branch meristems, floral meristems and developing floral organ primordia. PCR analyses for cDNA libraries derived from reverse transcription of total RNAs showed that CorLFY was also expressed during the late-stage development of flowers and inflorescences, as well as in bracts and developing leaves. Consistent differences in the CorLFY expression patterns were not detected among the distinct inflorescence types.


CONCLUSIONS
The results suggest a role for CorLFY genes during floral and inflorescence development in dogwoods. However, the failure to detect expression differences between the inflorescence types in the Cornus species analysed suggests that the evolutionary shift between major inflorescence types in the genus is not controlled by dramatic alterations in the levels of CorLFY gene transcript accumulation. However, due to spatial, temporal and quantitative limitations of the expression data, it cannot be ruled out that subtle differences in the level or location of CorLFY transcripts may underlie the different inflorescence architectures that are observed across these species. Alternatively, differences in CorLFY protein function or the expression or function of other regulators (e.g. TFL1 and UFO homologues) may support the divergent developmental trajectories.}, number={8}, journal={Annals of Botany}, publisher={Oxford University Press (OUP)}, author={Liu, Juan and Franks, Robert G. and Feng, Chun-Miao and Liu, Xiang and Fu, Cheng-Xin and (Jenny) Xiang, Qiu-Yun}, year={2013}, month={Nov}, pages={1629–1641} }
 @article{liu_feng_franks_qu_xie_xiang_2013, title={Plant regeneration and genetic transformation of C. canadensis: a non-model plant appropriate for investigation of flower development in Cornus (Cornaceae)}, volume={32}, ISSN={0721-7714, 1432-203X}, url={http://link.springer.com/10.1007/s00299-012-1341-x}, DOI={10.1007/s00299-012-1341-x}, abstractNote={KEY MESSAGE : Efficient Agrobacterium -mediated genetic transformation for investigation of genetic and molecular mechanisms involved in inflorescence architectures in Cornus species. Cornus canadensis is a subshrub species in Cornus, Cornaceae. It has recently become a favored non-model plant species to study genes involved in development and evolution of inflorescence architectures in Cornaceae. Here, we report an effective protocol of plant regeneration and genetic transformation of C. canadensis. We use young inflorescence buds as explants to efficiently induce calli and multiple adventitious shoots on an optimized induction medium consisting of basal MS medium supplemented with 1 mg/l of 6-benzylaminopurine and 0.1 mg/l of 1-naphthaleneacetic acid. On the same medium, primary adventitious shoots can produce a large number of secondary adventitious shoots. Using leaves of 8-week-old secondary shoots as explants, GFP as a reporter gene controlled by 35S promoter and hygromycin B as the selection antibiotic, a standard procedure including pre-culture of explants, infection, co-cultivation, resting and selection has been developed to transform C. canadensis via Agrobacterium strain EHA105-mediated transformation. Under a strict selection condition using 14 mg/l hygromycin B, approximately 5 % explants infected by Agrobacterium produce resistant calli, from which clusters of adventitious shoots are induced. On an optimized rooting medium consisting of basal MS medium supplemented with 0.1 mg/l of indole-3-butyric acid and 7 mg/l hygromycin B, most of the resistant shoots develop adventitious roots to form complete transgenic plantlets, which can grow normally in soil. RT-PCR analysis demonstrates the expression of GFP transgene. Green fluorescence emitted by GFP is observed in transgenic calli, roots and cells of transgenic leaves under both stereo fluorescence microscope and confocal microscope. The success of genetic transformation provides an appropriate platform to investigate the molecular mechanisms by which the various inflorescence forms are developed in Cornus plants.}, number={1}, journal={Plant Cell Reports}, publisher={Springer Science and Business Media LLC}, author={Liu, Xiang and Feng, Chun-Miao and Franks, Robert and Qu, Rongda and Xie, De-Yu and Xiang, Qiu-Yun Jenny}, year={2013}, month={Jan}, pages={77–87} }
 @article{feng_liu_yu_xie_franks_xiang_2012, title={Evolution of bract development and B‐class MADS box gene expression in petaloid bracts of
            Cornus
            s. l. (Cornaceae)}, volume={196}, ISSN={0028-646X 1469-8137}, url={http://dx.doi.org/10.1111/j.1469-8137.2012.04255.x}, DOI={10.1111/j.1469-8137.2012.04255.x}, abstractNote={Despite increasing interest in the molecular mechanisms of floral diversity, few studies have investigated the developmental and genetic bases of petaloid bracts. This study examined morphological patterns of bract initiation and expression patterns of B-class MADS-box genes in bracts of several Cornus species. We suggest that petaloid bracts in this genus may not share a single evolutionary origin. Developmental pathways of bracts and spatiotemporal expression of B-class genes in bracts and flowers were examined for four closely related dogwood species. Divergent morphological progressions and gene expression patterns were found in the two sister lineages with petaloid bracts, represented by Cornus florida and Cornus canadensis. Phylogeny-based analysis identified developmental and gene expression changes that are correlated with the evolution of petaloid bracts in C. florida and C. canadensis. Our data support the existence of independent evolutionary origins of petaloid bracts in C. canadensis and C. florida. Additionally, we suggest that functional transference within B-class gene families may have contributed to the origin of bract petaloidy in C. florida. However, the underlying mechanisms of petaloid bract development likely differ between C. florida and C. canadensis. In the future this hypothesis can be tested by functional analyses of Cornus B-class genes.}, number={2}, journal={New Phytologist}, publisher={Wiley}, author={Feng, Chun‐Miao and Liu, Xiang and Yu, Yi and Xie, Deyu and Franks, Robert G. and Xiang, Qiu‐Yun (Jenny)}, year={2012}, month={Aug}, pages={631–643} }
 @article{feng_xiang_franks_2011, title={Phylogeny-based developmental analyses illuminate evolution of inflorescence architectures in dogwoods (Cornus s. l., Cornaceae)}, volume={191}, ISSN={["1469-8137"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79960555236&partnerID=MN8TOARS}, DOI={10.1111/j.1469-8137.2011.03716.x}, abstractNote={• Inflorescence architecture is important to angiosperm reproduction, but our knowledge of the developmental basis underlying the evolution of inflorescence architectures is limited. Using a phylogeny-based comparative analysis of developmental pathways, we tested the long-standing hypothesis that umbel evolved from elongated inflorescences by suppression of inflorescence branches, while head evolved from umbels by suppression of pedicels. • The developmental pathways of six species of Cornus producing different inflorescence types were characterized by scanning electron microscopy (SEM) and histological analysis. Critical developmental events were traced over the molecular phylogeny to identify evolutionary changes leading to the formation of umbels and heads using methods accounting for evolutionary time and phylogenetic uncertainty. • We defined 24 developmental events describing the developmental progression of the different inflorescence types. The evolutionary transition from paniculate cymes to umbels and heads required alterations of seven developmental events occurring at different evolutionary times. • Our results indicate that heads and umbels evolved independently in Cornus from elongated forms via an umbellate dichasium ancestor and this process involved several independent changes. Our findings shed novel insights into head and umbel evolution concealed by outer morphology. Our work illustrates the importance of combining developmental and phylogenetic data to better define morphological evolutionary processes.}, number={3}, journal={NEW PHYTOLOGIST}, author={Feng, Chun-Miao and Xiang, Qiu-Yun and Franks, Robert G.}, year={2011}, pages={850–869} }
 @article{feng_manchester_xiang_2009, title={Phylogeny and biogeography of Alangiaceae (Cornales) inferred from DNA sequences, morphology, and fossils}, volume={51}, ISSN={["1095-9513"]}, DOI={10.1016/j.ympev.2009.01.017}, abstractNote={Alangiaceae, in the basal Asterid clade Cornales, consists of only one genus, Alangium. The genus has approximately 24 species distributed mainly in tropical and subtropical regions of the Old World and is well represented in the Tertiary fossil record of the northern hemisphere. We conducted phylogenetic and biogeographic analyses for Alangium by integrating data from DNA sequences, morphology, and fossils to evaluate systematic and biogeographic hypotheses. The results largely agree with the traditional classification of four sections within the genus, and suggest sects. Conostigma and Rhytidandra are successive sister taxa to a clade containing sects. Marlea and Alangium. Our results also indicate that the widespread species A. chinense consists of at least two lineages meriting recognition as distinct species. Biogeographic analysis using DIVA and divergence time dating with the Bayesian method (MULTIDIVTIME) resolved the ancestor of Alangium as being in S.E. Asia in the Late Cretaceous. Several intercontinental migrations involving the margin of the Tethys seaway (TESW), the North Atlantic land bridge (NALB) or the Bering land bridge (BLB), and long-distance dispersals are suggested. The results support TESW for plant migration of thermophilic (including evergreen) taxa in the early Tertiary.}, number={2}, journal={MOLECULAR PHYLOGENETICS AND EVOLUTION}, author={Feng, Chun-Miao and Manchester, Steven R. and Xiang, Qiu-Yun}, year={2009}, month={May}, pages={201–214} }