Transcript Dwarfism in Sorghum bicolor converted by Dw3

Dwarfism in Sorghum bicolor
converted by dw3
http://millbafs.com/for
age-seeds/
Sorghum bicolor
•
•
•
•
•
North - African origin
5th most important cereal crop in the world
Multipurpose crop (forage, biofuel, food)
Poaceae family
Wide range of adaptation, drought resistance,
and salinity tolerance
• 2007 whole genome sequenced (730 mbp)
Dwarfing alleles
• Culms 0.6 – 5 m tall
• 4 height loci (Dw1 , Dw2 , Dw3 and Dw4 )
with 4 independent dwarfing mutations (dw1,
dw2, dw3 and dw4)
• Plant height reduction from 3m to 60 cm
• Reduction of the length of the internodes
without affecting other agronomic traits
http://southeastfarmpress.com
dw3
• 2003 Dw3 gene was cloned
• Encodes a transmembrane protein of the
adenosine triphosphate-binding cassette (ABC)
transporter superfamily involved in auxin efflux
• Recessive dw3 mutant allele contains an 882 bp
tandem duplication in exon 5 resulting in a
nonfunctional enzyme
 Reduction in seedling auxin transport
 Reduced stalk height and thicker stems
Instability of dw3
• Reversion to wild-type at a frequency from
0.166 to 0.3%
• dw3 can undergo unequal crossing over
during meiosis
• The reversion rate is genotype dependent
(Multani et. al, 2013)
Solving the instability problem
• Identification of natural variants of dw3
• Stable mutant phenotype
• No duplication event - No spontaneous
reversion to Dw3
• new alleles: dw3-sd1, dw3-sd2
References
• Multani DS et al., 2003, Loss of an MDR transporter in compact stalks of
maize br2 and sorghum dw3 mutants. Science. Oct 3;302(5642):81-4.
• Geoffrey P. Morris et al., 2013, Population genomic and genome-wide
association studies of agroclimatic traits in sorghum. PNAS 453/8
• B. George-Jaegglia, 2011, Decrease in sorghum grain yield due to the dw3
dwarfing gene is caused by reduction in shoot biomass. ELSEVIER
• Ivan D. Barrero Farfan et al. (2012), A Stable dw3 Allele in Sorghum and a
Molecular
• Marker to Facilitate Selection. Crop Science , Vol . 52 ,
September/October
• Patrick J. Brown et al., 2008, Efficient Mapping of Plant Height
Quantitative Trait Loci in a Sorghum Association Population With
Introgressed Dwarfing Genes. Genetics 180: 629–637 (September)
• Hari D. Upadhyaya et al., 2010, Association mapping of maturity and plant
height using SNP markers with the sorghum mini core collection. Springer,
Theor Appl Genet (2013) 126:2003–2015,
• http://plants.usda.gov/plantguide/pdf/pg_sobi2.pdf