flower initiation, developments and senescence mechanism in roses and its regulatory genes were explanined

1. Genetics and genomics of
flower initiation and development in roses
Aparna Veluru
Roll No-10134

2. Schematic representation of major steps of modern rose genealogy
Raymond (1999)

3. Floral initiation and development
Floral initiation Floral organogenesis Visible flower
Dubois et al.,2011

4. Genotypes :
Continuous Vs Once flowering
Single Vs Double flowering
Flowering stages: Floral meristem initiation to flower
senescence
Approach: Affymetrix microarray (Rosa1_Affyarray tool
containing sequences representing 4765 unigenes expressed
during flower development)
RT-PCR analysis validated the mRNA accumulation changes
observed in microarray hybridization for a selection of 24
genes expressed at either high or low levels
Dubois et al.,2011

5. Gene expression associated with rose floral initiation
VM1-VM2-FM: 824 (Rw) 652 (Rh) DE
336 (Rw) , 301 (Rh) UR
488 (Rw), 352 (Rh) DR
Overlapping genes: 222 (91UR, 131 DR)
PFA- Rh SOC1, Rh AP1, auxin induced homologues
PFR- auxin repressed homologues, ACC oxidase, ACC synthase, EIN, EIL
transcription factors
Dubois et al.,2011

6. Gene expression associated with rose floral development
Transcriptome analysis-EF
135-DE- 46(1+2) to (3+4),
105 (3+4) to 5
PUR- ACC synthase, Rh AP3,
Rh AG, Rh PI, extracellular
lipases, xyloglucon endotrans
GS/HL, pectin esterase's,
pectin lyases, gibberellin 2-
oxidase
Early to late floral transition
401 DE- 233DR, 168
UR(stage5-VP)
PUR-carotene and anthocyanin
genes, MYB, SHP, NAC
PDR-Cyclin dependant kinases
Late floral
development
456 DE- similar as
(stg5-vp)
OF-SF- PUR
chlorophyll catabolic
Cellular N2 catabolic
Rb XTH1, Rb EXPA1
Dubois et al.,2011

7. Dubois et al.,2011
q PCR- analysis of six
differentially expressed genes
using rose floral organogenesis,
floral opening and senescence in
R. chinensis OB

8. Recurrent flowering and flowering time in roses
Iwata et al.,2012

9. Iwata et al. (2012)
Continuous flowering habit in rose is controlled by a recessive
major gene- Recurrent blooming (Albani et al., 2004)
The phenotype may have arisen from a mutation in natural
population. The rose mutant was thought to be selected from
wild Rosa chinensis in china (Hurst, 1941)
Continuous flowering habit affects other important
developmental characters
 Short juvenile phase
 Determinate growth habit
 Self- inductive flowering habit

10. Phylogenetic analysis of members of Rose FT and TFL1 family
Iwata et al. (2012)

11. Iwata et al. (2012)
Insertional polymorphism at the Ro KSN locus between OF and CF and Cl roses
PCR amplification of the RoKSN gene in
R. chinensis (CF and Non –CF cultivars)

12. Iwata et al. (2012
Effect of the insertion of the Copia- like retrotransposon on splicing of the
second intron of RoKSN

13. Iwata et al. (2012)
RoKSN
RoFT
RoFLY
Seasonal accumulation
of RoKSN, RoFT and
RoLFY transcripts in the
once-flowering
R. Wichuriana

14. Models showing the control of flowering for once-
and recurrent-flowering Rosa sp.
Iwata et al. (2012) and Koskela et al. (2012)

15. ABCDE modal of flower organ identity
Determination of rose flower organ identity and morphogenesis
A class- Rh AP1, RhAP2
B class- MASAKO B3/ Rh AP3,
MASAKO eu B3/ Rh TM6, MASAKO
BP/ Rh PI
C class- MASAKO C/ Rh AG
D class- MASAKO D/ Rh SHP
Rose floral organ identity genes

16. Dubois, 2010
Simplified
genealogy of roses

17. Floral architecture of Malmaision
and St. Annes
Similarities in volatile components of both the cultivars
Dubois et al.,2010

18. Floral organs
Floral organ number in Malmaision and St. Annes
Dubois et al.,2010

19. Dubois et al.,2010
Longitudinal section of floral meristem and flowers during
floral organogenesis

20. Dubois et al.,2010
Rh AG expression levels in
both the cultivars

21. Dubois et al.,2010
Insitu hybridization using Rh AG antisense probe on early stage flowers of
cultivated roses and their likely wild ancestor

22. Dubois et al.,2010
Model for selection of double flowers

23. Anthocyanin biosynthetic pathway Katsumuto et al., 2007
Flower colour

24. Rose flower as machinery for scent production

25. Floral volatiles in rose –Terpenoids, phenyl propanoids and fatty acid derivatives
European origin- 2-PE, terpenoids Chinese origin- PME (DMT,TBB)
A. Origin of Tea scented roses, B. Proposed path way for the synthesis of DMT

26. Molecular modelling of
OOMT1,OOMT2
Substrate specificity of OOMTs
TLC analysis of reaction products
produced after incubation of native
and mutant OOMTs with Orcinol
Characterization of OOMT like proteins
A. Specific activities of OOMT like enzymes
with Orcinol, MHT
B. Western blot analysis of OOMT
expression in selected rose Sps
(R. banksiae, R.bracteata, R. canina, Ra,
R. majalis, R.marette, R.rugosa, R.gallica,
R.beggerian, R.chinensis OB, R.chinensis SN,
R.gigantea, R.odorata HB, R.odorata PYCR,
R.hugonis, R.wichuriana, R.roxburghii )

27. Flower senescence
Increased ABA, H2O2, reduced water potential, anti oxidant
enzymes (Kumar et al., 2006)
Action of ABA remain uncharacterized, no repot on
autophagy, protein and nucleic acid degradation, protein turn
over and nutrient remobilization
Expansin 1A (Rb EXPA1), Pectic lyase 1( Rb PEL1) increases
in abscission zone during the course of natural abscission
Xyloglucon endotrans glucosylase/ hydrolase (Rb XTH1 and
Rb XTH2 shown to be induced in senescing petals

28. Singh et al., 2012
Comparative transcriptome analysis
of different Rb XTH genes in
ethylene untreated and treated
tissues of R. bourboniana
determined by RT-PCR when cut
roses are treated with 0.5µl/L
A family of xyloglucon endo transglycosylase/ hydrolase genes were studied to
understand their role in petal abscission in flowers of R .bourboniana and R.
hybrida
Identified nine new XTHs genes showed differential expression during flower
opening and abscission

29. Singh et al., 2012
RT-PCR analysis of RbXTH4,
RbXTH7, Rb XTH9 transcript
accumulation in abscission
zones in 0.5µl/L ethylene
treated flowers and natural
abscised flower
RT-PCR analysis of RbXTH3, RbXTH6,
transcript accumulation in abscission
zones in 0.5µl/L ethylene treated flowers
and natural abscised flower

30. Singh et al., 2012
RT-PCR analysis of RbXTH5, Rb XTH
12, transcript accumulation in
abscission zones in 0.5µl/L ethylene
treated flowers and natural abscised
flower
RT-PCR analysis of RbXTH
transcript accumulation in
abscission zones in 15µl/L ethylene
treated flowers of R. bourboniana
compared with untreated control

31. Trait Linkage group authors
Recurrent blooming
(RB)
LG-3 Spiller et al., 2011
Double flower
(d6)
LG-3 Crespel., 2002
Pink flower (Blfo) LG-2 Debener and
Mattiesh., 1999
Nerol LG-3 Spiller., 2012
Nerol acetate LG-4 Spiller., 2012
Qualitative genes of roses

32. Blush Noisette (D10)
2n=14
Rosa wichuriana (E15)
2n=14
X
98 F1 segregating progeny
Flower colour-Pink
flower type :Double
Thorny type
Plant type- Spreading
Blooming-recurrent
PM-susceptibility
Flower colour-white
flower type :single
Thorn less type
Plant type- Creeping
Blooming-once in a year
PM- resistant
Dugo et al, 2005
133 (130 RAPD, 1morphological, 2 microsatellites

33. 388 cM
260 cM
Dugo et al, 2005

34. Conclusions
Past decade witnessed the development of number of molecular and
genetic tools for the study of rose
The identification of genes whose expression correlates with important
ornamental traits can facilitate and accelerate candidate gene identification
for rose breeding by marker assisted selection
Recently , the ‘Rose genome sequencing initiative (RGSI) initiated the rose
genome sequencing, this will help to understand the molecular bases for
important ornamental traits