May 4, 2008
Source:
Checkbiotech and Nature
Genetics
Natural genetic variant
regulates yield potential in rice
Researchers have identified a gene that has significant effects
on yield potential in rice, as well as adaptability of rice to
temperate climates. The study, published online this week in
Nature Genetics, has
implications for rice productivity.
The productivity of many crop plants, including rice, is
determined by yield potential, plant height and flowering time.
Previous studies have identified a region on chromosome 7 that
affected all three traits, but the specific gene involved has
not yet been pinpointed.
Qifa Zhang and colleagues found that rice plants that are
shorter, have fewer grains per cluster of flowers, and flower
earlier - all traits that reduce yield - have a complete
deletion of the gene Ghd7. The restoration of Ghd7 expression in
plants with the deletion had considerable effects on
yield-related traits, including a doubling of the time to
flowering and a 67% increase in height.
The authors also determined the status of Ghd7 in 19 rice
varieties from rice growing in a wide geographic range in Asia.
Five different versions of Ghd7 were found. The most highly
active versions were present in warmer regions, allowing rice
plants to fully exploit light and temperature by delaying
flowering and increasing yield. Less active or inactive versions
were found in cooler regions, enabling rice to be cultivated in
areas where the growing season is shorter.
Source: Nature
Genetics
Natural variation in Ghd7 is an important
regulator of heading date and yield potential in
rice
Weiya Xue1,2, Yongzhong Xing1,2, Xiaoyu Weng1, Yu
Zhao1, Weijiang Tang1, Lei Wang1, Hongju Zhou1,
Sibin Yu1, Caiguo Xu1, Xianghua Li1 &
Qifa Zhang1
1. National Key Laboratory of Crop Genetic
Improvement, National Centre of Plant Gene Research
(Wuhan)
2. Huazhong
Agricultural University, Wuhan 430070, China.
These authors contributed equally to this work.
Published online: 4 May 2008 | doi:10.1038/ng.143
ABSTRACT
Yield potential, plant height and
heading date are three classes of traits that determine the
productivity of many crop plants. Here we show that the
quantitative trait locus (QTL) Ghd7, isolated from an elite rice
hybrid and encoding a CCT domain protein, has major effects on
an array of traits in rice, including number of grains per
panicle, plant height and heading date. Enhanced expression of
Ghd7 under long-day conditions delays heading and increases
plant height and panicle size. Natural mutants with reduced
function enable rice to be cultivated in temperate and cooler
regions. Thus, Ghd7 has played crucial roles for increasing
productivity and adaptability of rice globally.
Access to full article for subscribers:
http://www.nature.com/ng/journal/vaop/ncurrent/abs/ng.143.html |
Chinese scientists find 'yield-improving rice gene' - The
newly discovered gene may help improve rice yields
Source:
Jia Hepeng,
Sci.DevNet
May 14, 2008
Chinese
scientists have identified a rice gene that could
simultaneously control the crop's yield, plant height, and
number of days to flowering.
Publishing their study in
Nature Genetics online this month (4 May), researchers
from Wuhan-based Huazhong Agricultural University (HZAU) say
the gene could play a role in improving rice productivity.
The scientists found that in individual rice breeds, the
three traits appear strong –– or weak –– simultaneously.
"This fact makes us infer that the three traits were
controlled by a single gene," says Xing Yongzhong, one of
the lead authors and a professor at HZAU.
Previous studies have found that a region on chromosome
seven of rice can regulate all three traits but the specific
gene involved had not been discovered.
The HZAU scientists mapped the relevant gene site on
chromosome seven and located the specific gene named Ghd7.
They discovered that shorter rice plants with fewer grains
per cluster of flowers and earlier flowering do not have the
gene Ghd7.
When they transferred Ghd7 into Ghd7-free varieties of rice,
they found that time to flowering was increased by 105 per
cent, they grew around 70 per cent taller, and the plants
had more rice grains per cluster of flowers.
Numerous rice genes have been reported to control such
traits alone, but Ghd7 is notable because of its large,
multiple effects on an array of traits, write the authors.
Xing told SciDev.Net that the gene could be incorporated
into varieties with traditional breeding. "Although we have
used the genetically modified method in the study, we need
not adopt this method in the practical seeding because the
gene is identified from the rice itself."
The team of scientists also studied the status of Ghd7 in 19
rice varieties from rice growing in a wide geographic range
in Asia and found five different versions of the gene.
"We are exploring the subtypes of Ghd7-containing rice that
are most suitable to their growing regions, so as to
cultivate the most appropriate high-output rice varieties,"
Xing adds.
Huang Dafang, former director of the Institute of
Biotechnologies of the Chinese Academy of Agricultural
Sciences, welcomes the study as a major scientific
breakthrough.
But he says that usually, multiple genes regulate the traits
related to rice yields, and whether the Ghd7 could play its
claimed role in promoting yields needs further research and
seeding tests.
Link to
full paper in Nature Genetics
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