News release 27-may-2022 kkplan liar

 
No photosynthetic improvement in ictB
transformants in field-grown model crop
Peer-Reviewed Publication
CARL R. WOESE INSTITUTE FOR GENOMIC BIOLOGY, UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
CHAMPAIGN, Ill. — It is projected that by the year 2050, the global
food supply will need to increase by 50-80% to keep up with the
growing population. Researchers all over the world have been
working to find ways to sustainably grow food crops to meet this
need, and improving photosynthesis in plants holds great
possibilities to solving these issues.
In a recent study, published in the Journal of Experimental Botany, a
team of Illinois researchers tested the potential for increased plant
productivity and intrinsic water-use efficiency through the
overexpression of inorganic carbon transporter B (ictB) in field-grown
tobacco. However, their results showed no significant difference
between the field-grown ictB expressing tobacco lines and wild-type.
This research was done in collaboration with the University of Essex
researchers Christine Raines, the corresponding author of this study,
alongside Kenny Brown, Chidi Afamefule, Hussein Gherli, Andrew
Simkin, and Tracy Lawson. The tobacco transformants were
produced at Essex, where the ictB single construct was placed in tobacco cv. Samsun background. The tobacco
transformants and wild-type tobacco plants were grown at the Energy Farm at Illinois.
“Our results indicated that ictB overexpression may only benefit crops grown in controlled environments, such as
greenhouses,” said Ursula Ruiz-Vera, a former postdoctoral researcher at the University of Illinois Urbana-Champaign,
who led this study for a research project called Realizing Increased Photosynthetic Efficiency (RIPE). “If the benefits of
the ictB overexpression can only be seen in plants grown in controlled environments, it is worth a deeper exploration
of this method under these conditions which can benefit crops that use environments like greenhouses, like vegetable
crops. However, this method may not be the most efficient way to increase food production under field conditions.”
Ruiz-Vera now works as a Senior Scientist, Control Environment Plant Physiologist at Bayer Crop Science.
RIPE, which is led by Illinois, is engineering crops to be more productive by improving photosynthesis. RIPE is
supported by the Bill & Melinda Gates Foundation, Foundation for Food & Agriculture Research, and U.K. Foreign,
Commonwealth & Development Office.
Plants fall under two main types of photosynthesis, C and C . The difference between these two is that C plants
operate a carbon concentration mechanism (CCM), which increases the CO; concentration around the enzyme
Rubisco. Because of this CCM, C plants tend to have greater water- and nitrogen-use efficiency.
However, most major food crops consumed by humans utilize the less efficient C photosynthetic pathway, prompting
initiatives to improve C crops. Several studies over the years have suggested that overexpressing the ictB gene would
improve photosynthetic efficiency in C plants.
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IMAGE: URSULA RUIZ-VERA COLLECTING SAMPLES
FROM ICTB FIELD TRIAL. view more ;
CREDIT: CLAIRE BENJAMIN/RIPE PROJECT
Much of RIPE’s testing of improvements to photosynthesis has been done using tobacco plants, as they are a
convenient proof-of-concept crop. Since tobacco is easy to genetically transform, due to its ability to produce a large
amount of seed that would shorten testing cycles, this makes it easier to transfer the successful genetic traits to be
mirrored in food crops such as cowpea, cassava, and soybean.
The team tested four tobacco ictB transformants for photosynthetic performance in field-based conditions relative to
wild-type based on previous studies that had shown ictB tobacco transformants increased photosynthetic efficiency
and biomass without affecting water-use efficiency.
“Most of the previous studies have been performed in controlled conditions and it isn’t clear if these improvements in
plant productivity could be translated to crops in the field,” said Liana Acevedo-Siaca, who co-led this study at Illinois
during her time as a postdoctoral researcher. “In this experiment, we wanted to grow ictB tobacco plants in the field to
evaluate if these transgenic plants have a higher photosynthetic efficiency than wild-type under field conditions.”
Overall, their findings suggested that the transformants did not perform better than wild-type on photosynthesis,
biomass, and leaf composition related traits, in contrast to previous studies that suggested otherwise. However, there
remains optimism that ictB still holds value in contributing to the improvement of crop yields, as results from previous
studies had shown significant gains for biomass production with ictB overexpression.
More research should be conducted to fully understand the function of the gene and in which environmental
conditions it offers the greatest benefit to crop performance, helping to meet the increased global demands for food.
“Although previous results showed benefits in greenhouses and controlled environments for ictB transformants, there
is a bright side as well,” said Acevedo-Siaca, who now works as an Associate Scientist in the Global Wheat Program at
the International Maize and Wheat Improvement Center (CIMMYT) in Mexico. “As we look to increase food production
sustainably, agriculture in greenhouses and vertical farming may benefit from ictB overexpression.”
RIPE is led by the University of Illinois in partnership with The Australian National University, Chinese Academy of
Sciences, Commonwealth Scientific and Industrial Research Organisation, Lancaster University, Louisiana State
University, University of California, Berkeley, University of Cambridge, University of Essex, and U.S. Department of
Agriculture, Agricultural Research Service.
JOURNAL
Journal of Experimental Botany
DOI
10.1093/jxb/erac193 ;
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
Not applicable
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ARTICLE TITLE
Field-grown ictB tobacco transformants show no difference in photosynthetic efficiency for biomass relative to
wildtype
ARTICLE PUBLICATION DATE
13-May-2022
COI STATEMENT
No conflicts of interest.
Media Contact
Amanda Nguyen
Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
amandan2@illinois.edu
Office: 773-562-6581
Expert Contact
Christine Raines
University of Essex
rainc@essex.ac.uk