Researchers from Purdue University and the University of Nebraska-Lincoln have discovered a soybean gene whose mutation affects plant stem growth, a finding that could lead to the development of improved soybean cultivars for the northern United States.
Purdue agronomy professor Jianxin Ma (pronounced Jen-SHIN' Ma) and collaborators identified a gene known as Dt2, which causes semideterminacy in soybean plants. Semideterminate soybean plants - mid-size plants that continue vegetative growth even after flowering - can produce as many or more pods than current northern cultivars but do not grow as tall. Their reduced height makes them more resistant to lodging, a bending or breaking of the main plant stem.
"This gene could help us improve the yield potential and adaptability of soybeans for specific growing areas," Ma said. "We can now focus on developing a variety of elite semideterminate soybean cultivars, which could perform very well in high-yielding, irrigated environments such as Nebraska and northeastern Indiana."
Soybean cultivars are often divided into two groups: indeterminate - tall plants whose main stem continues to grow after flowering - and determinate - shorter, bushier plants whose main stem halts growth when blossoms begin to form.
Determinate soybean plants thrive in the longer growing season of the south while indeterminate plants' overlapping vegetative and reproductive stages make them better suited to the north. But the height of indeterminate cultivars renders them prone to lodging.
For northern soybean producers, semideterminate soybean plants could represent a "Goldilocks" cultivar, a "just right" alternative between the two. Semideterminate soybeans are easy to manage, have similar or better yields than indeterminate plants and can handle a short growing season, Ma said.
Only one semideterminate soybean cultivar, NE3001, is common in the United States. Having pinpointed Dt2 will enable Ma and his researchers to use natural plant breeding methods to develop a variety of semi-determinate cultivars.
"The potential for soybean yield productivity in the U.S. has not been fully explored, in part because of the lack of semideterminate cultivars," he said. "We're now working on converting high-yielding indeterminate cultivars to semideterminate types to test their yield potential."
Ma - who had previously identified Dt1, the gene that causes indeterminancy in soybeans - used an integrated genetic approach to isolate and characterize Dt2. After identifying the gene, he inserted it into indeterminate cultivars to confirm that it caused the plants to become semideterminate. Dt2 suppresses the expression level of Dt1, causing soybean plants to grow shorter.
Ma said this type of mutation appears to be unique to soybeans as semideterminancy in other plants such as tomatoes and chickpeas is caused by a different genetic mechanism.
Study co-author James Specht, a professor of agronomy and horticulture at the University of Nebraska-Lincoln, said the identification of Dt2 gives soybean breeders a powerful tool for breeding new cultivars.
"This provides breeders with a perfect genetic marker for identifying semideterminancy in soybean seeds and seedlings," he said.
The paper was published in The Plant Cell and is available at http://www.plantcell.org/content/early/2014/07/08/tpc.114.126938.full.pdf+html
Other collaborators on the study are Thomas Clemente at the University of Nebraska-Lincoln, Randall Nelson at the U.S. Department of Agriculture and the University of Illinois and Lijuan Qiu at the Chinese Academy of Agricultural Sciences.
Funding for the research was provided mainly by the United Soybean Board and partially by the Partnership for Research and Education in Plant Breeding and Genetics program of the U.S. Department of Agriculture’s National Institute of Food and Agriculture, Ag Alumni Seed, AgReliant Genetics, Beck’s Hybrids, ConAgraFoods, Dow AgroSciences, Indiana Crop Improvement Association and Pioneer Hi-Bred International.
Writer: Natalie van Hoose, 765-496-2050, email@example.com
Sources: Jianxin Ma, 765-496-3662, firstname.lastname@example.org
James Specht, 402-472-1536, email@example.com
Dt2 is a gain-of-function MADS-domain factor gene that specifies semideterminancy in soybean
Jieqing Ping 1; Yunfeng Liu 1; Lianjun Sun 1; Meixia Zhao 1; Yinghui Li 2; Maoyun She 1; Yi Sui 1; Feng Lin 1; Xiaodong Liu 1; Zongxiang Tang 1; Hanh Nguyen 3; Zhixi Tian 1; Lijuan Qiu 2; Randall L. Nelson 4; Thomas E. Clemente 3; James E. Specht 3; Jianxin Ma 1
1 Department of Agronomy, Purdue University, West Lafayete, Indiana 47907
2 Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
2 Department of Agronomy and Horticulture/Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, Nebraska 68583
4 Soybean/Maize Germplasm, Pathology, and Genetics Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801
Similar to Arabidopsis thaliana, the wild soybeans (Glycine soja) and many cultivars exhibit indeterminate stem growth specified by the shoot identity gene Dt1, the functional counterpart of Arabidopsis TERMINAL FLOWER1 (TFL1). Mutations in TFL1 and Dt1 both result in the shoot apical meristem (SAM) switching from vegetative to reproductive state to initiate terminal flowering and thus produce determinate stems. A second soybean gene (Dt2) regulating stem growth was identified, which, in the presence of Dt1, produces semideterminate plants with terminal racemes similar to those observed in determinate plants. Here, we report positional cloning and characterization of Dt2, a dominant MADS domain factor gene classified into the APETALA1/SQUAMOSA (AP1/SQUA) subfamily that includes floral meristem (FM) identity genes AP1, FUL, and CAL in Arabidopsis. Unlike AP1, whose expression is limited to FMs in which the expression of TFL1 is repressed, Dt2 appears to repress the expression of Dt1 in the SAMs to promote early conversion of the SAMs into reproductive inflorescences. Given that Dt2 is not the gene most closely related to AP1 and that semideterminancy is rarely seen in wild soybeans, Dt2 appears to be a recent gain-of-function mutation, which has modified the genetic pathways determining the stem growth habit in soybeans.
Ag Communications: (765) 494-2722;
Keith Robinson, firstname.lastname@example.org
Natalie van Hoose | Eurek Alert!
Study shines light on brain cells that coordinate movement
26.06.2017 | University of Washington Health Sciences/UW Medicine
New insight into a central biological dogma on ion transport
26.06.2017 | Aarhus University
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology