Nav: Home

Soybean plants with fewer leaves yield more

November 18, 2016

Using computer model simulations, scientists have predicted that modern soybean crops produce more leaves than they need to the detriment of yield--a problem made worse by rising atmospheric carbon dioxide. They tested their prediction by removing about one third of the emerging leaves on soybeans and found an 8% increase in seed yield in replicated trials. They attribute this boost in yield to increased photosynthesis, decreased respiration, and diversion of resources that would have been invested in more leaves than seeds.

"The reduction in leaves allows more sun light to penetrate through the canopy making the whole plant more productive, and it also reduces crop water demand," said the project lead Praveen Kumar, Lovell Professor of Civil and Environmental Engineering at the University of Illinois.

Currently, we only achieve a 1% annual increase in yields due to crop improvements, which has slowed in the last decade. "This rate is insufficient to fulfill the needs for global food security, where we need to produce 70-100% more food by 2050 to feed an estimated 9.7 billion people," said project co-lead Steve Long, Gutgsell Endowed Professor of Plant Biology and Crop Sciences at the Carl R. Woese Institute for Genomic Biology at Illinois.

"We are trying to identify non-conventional techniques that can give us a quick boost in yield so that we can get closer to those predicted demands," said first author Venkatraman Srinivasan, a postdoctoral researcher at Illinois. "Soybeans are one of the four major staple crops and also the most important vegetable protein source in the world. If we can increase the yield of soybeans, we can solve the problems of protein demand and food production at the same time."

Published in Global Change Biology, their paper found that soybean plants produce too many leaves, most of which are shaded and inefficient, thereby wasting resources like water, carbon and nitrogen. "The model shows that by investing less in leaves, the plant can produce more seeds," Srinivasan said.

The model predicted that a 30-40% decrease in leaf area would increase yields by 8-10%. In field trials, they decreased leaf area (by manually cutting off new leaflets) by just 5% and still increased yields by 8%.

"The experiment indicates that that our model is conservative," Srinivasan said. "We hypothesize that plants with fewer leaves need less water, which requires fewer roots. Cutting down on roots could produce additional carbon savings that the plant can invest towards boosting yield. Alternatively, plants with fewer leaves are more water efficient, and thereby may be potentially drought tolerant."

Next, the researchers will bioengineer plants or search for varieties that naturally have fewer leaves to test these preliminary findings on a larger scale. They will also continue exploring ways to optimize other aspects of this crop's canopy of leaves--such as the distribution and angle of leaves--to design better soybean plants that yield more without the need for more water and other resources.

Srinivasan said, "We want to optimize the plant's canopy structure so that we can get as much photosynthesis as possible out of the crop to increase the food supply."
-end-
This work is part of Realizing Increased Photosynthetic Efficiency (RIPE), a multi-institutional research project that is developing high-yielding crops for farmers in Sub-Saharan Africa and Southeast Asia. Learn more about the project at http://ripe.illinois.edu/.

The paper "Decreasing, not increasing, leaf area will raise crop yields under global atmospheric change" was published in Global Change Biology (DOI: 10.1111/gcb.13526) and is available online or upon request. Funding from the National Science Foundation and RIPE project supported this research.

Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

Related Carbon Articles:

The carbon dioxide loop
Marine biologists quantify the carbon consumption of bacterioplankton to better understand the ocean carbon cycle.
Transforming the carbon economy
A task force commissioned in 2016 by former US Secretary of Energy Ernest Moniz has proposed a framework for evaluating R&D on recycling carbon dioxide and removing large amounts of CO2 from the atmosphere.
Closing the carbon loop
Research at the University of Pittsburgh's Swanson School of Engineering focused on developing a new catalyst that would lead to large-scale implementation of capture and conversion of carbon dioxide (CO2) was recently published in the Royal Society of Chemistry journal Catalysis Science & Technology.
An overlooked source of carbon emissions
Nations that pledged to carry out the Paris climate agreement have moved forward to find practical ways to reduce greenhouse gas emissions, including efforts to ban hydrofluorocarbons and set stricter fuel-efficiency standards.
Enabling direct carbon capture
Researchers have developed a solid material that can capture carbon dioxide from the atmosphere, even at very low concentrations.
More Carbon News and Carbon Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Teaching For Better Humans
More than test scores or good grades — what do kids need to prepare them for the future? This hour, guest host Manoush Zomorodi and TED speakers explore how to help children grow into better humans, in and out of the classroom. Guests include educators Olympia Della Flora and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#535 Superior
Apologies for the delay getting this week's episode out! A technical glitch slowed us down, but all is once again well. This week, we look at the often troubling intertwining of science and race: its long history, its ability to persist even during periods of disrepute, and the current forms it takes as it resurfaces, leveraging the internet and nationalism to buoy itself. We speak with Angela Saini, independent journalist and author of the new book "Superior: The Return of Race Science", about where race science went and how it's coming back.