SCIenTIFIC REPORTS | (2018) 8:4415 | DOI:10.1038/s41598-018-22798-5
Transcriptomic analysis of
transgressive segregants revealed
the central role of photosynthetic
capacity and eciency in biomass
accumulation in sugarcane
, Tyler Jones
, Ching Man Wai
, John Jifon
, Chifumi Nagai
, Ray Ming
Sugarcane is among the most ecient crops in converting solar energy into chemical energy. However,
due to its complex genome structure and inheritance, the genetic and molecular basis of biomass yield
in sugarcane is still largely unknown. We created an F2 segregating population by crossing S. ocinarum
and S. spontaneum and evaluated the biomass yield of the F2 individuals. The F2 individuals exhibited
clear transgressive segregation in biomass yield. We sequenced transcriptomes of source and sink
tissues from 12 selected extreme segregants to explore the molecular basis of high biomass yield for
future breeding of high-yielding energy canes. Among the 103,664 assembled unigenes, 10,115 and 728
showed signicant dierential expression patterns between the two extreme segregating groups in the
top visible dewlap leaf and the 9
culm internode, respectively. The most enriched functional categories
were photosynthesis and fermentation in the high-biomass and the low-biomass groups, respectively.
Our results revealed that high-biomass yield was mainly determined by assimilation of carbon in source
tissues. The high-level expression of fermentative genes in the low-biomass group was likely induced by
their low-energy status. Group-specic expression alleles which can be applied in the development of
new high-yielding energy cane varieties via molecular breeding were identied.
Sugarcane (Saccharum spp. Poaceae), the world’s leading biofuel crop, is among the most ecient crops in con-
verting solar energy into chemical energy and has a favorable input/output energy ratio
. e level of the input/
output energy ratio depends on cultural practices and the cropping cycle. It has been reported that the rst gen-
eration ethanol production sugarcane grown in Brazil under a 12 month crop cycle has an energy balance with
a greater than 1:8 energy input/output ratio
, while the input/output ratio in Louisiana (~9 month crop cycle), is
, both of which are much more energy ecient than corn at about 1:1.5-3
Sugarcane belongs to the genus Saccharum L. in the Poaceae family. e genus Saccharum includes six poly-
ploid species with variable size and number of chromosomes, namely S. spontaneum, S. robustum, S. ocinarum,
S. barberi, S. sinense, and S. edule
. Among these six species, S. spontaneum (2n = 40 to 128) and S. robustum
(2n = 60, 80, and up to 200) are wild species and the remaining four species, S. ocinarum, S. barberi, S. sin-
ense, and S. edule, are domesticated
. e initial high sugar content species S. ocinarum (2n = 80, x = 10) was
domesticated in New Guinea about 10,000 years ago, likely selected from a high sugar content S. robustum
Texas A&M AgriLife Research Center at Dallas, Texas A&M University System, Dallas, TX, 75252, USA.
Agriculture Research Center, Kunia, HI, 96759, USA.
Department of Plant Biology, University of Illinois at Urbana-
Champaign, Urbana, IL, 61801, USA.
Texas A&M AgriLife Research Center at Weslaco, Texas A&M University
System, Weslaco, TX, 78596, USA.
Center for Genomics and Biotechnology, Fujian Provincial Key laboratory of
Haixia applied plant systems biology, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry
University, Fuzhou, Fujian Province, China.
Department of Plant Pathology & Microbiology, Texas A&M University,
College Station, TX, 77843, USA. Correspondence and requests for materials should be addressed to Q.Y. (email:
Received: 16 October 2017
Accepted: 1 March 2018
Published: xx xx xxxx