2011 – 2020
Plants Will Think For Us
FORBES.com, Bruno Giussani, 09.13.10, 6:00 PM ET
You know a plant when you see one. Vegetables. They can’t move, communicate, sense or think.
Actually, Stefano Mancuso would like you to reconsider some of that. The Italian scientist runs a lab just outside Florence focusing on research into plant neurobiology: two words that aren’t obvious companions, given that the latter suggests that the former have some form of intelligence.
“If you define intelligence as the capacity to solve problems, plants have a lot to teach us,” says Mancuso. Ten years ago, while studying some roots, almost incidentally he discovered that a small part of the root called the apex is better protected and consumes more oxygen than the rest of the plant. Superior protection and a relatively higher oxygen consumption are two key characteristics of the animal brain.
Since then, Mancuso and other scientists have developed a body of research pointing convincingly to the fact that plants possess a sophisticated form of distributed intelligence that allows them to gather, process and even share information, as well as act on it.
Plants lack human-like nerves or neurons, but they have a dozen senses (including our five) and harness almost all the same neurotransmitters that we use in our brain. Their intelligence is spread out in the roots. Each root communicates with the nearest one in a network that is not unlike the Internet. If a piece is lost, the whole keeps working, and through this network they transmit electro-chemical signals that prompt very intelligent, and even surprisingly social, behavior.
The intelligence shows through when plants are attacked, says Mancuso, “If an insect is attacking the leaves of a tomato plant, in a few minutes you have all the nearby tomato plants knowing about it and secreting an inhibitor protein that makes the leaves unpalatable to that insect. We are talking about a completely different form of intelligence here. They can’t move, so if they had something like a brain, it could be eaten by a predator and be gone,” Mancuso explains.
“We’re still far from figuring out exactly how plant intelligence works,” says Mancuso. But he believes his research may contribute to the development of new, plant-inspired technologies in fields as diverse as robotics, telecommunication and energy. The most ambitious project ahead will harness some of this research to create plant-inspired robots, which he calls “plantoids.”
Mancuso hopes to be able to show the first of this new class of phytomorphic machines by 2013 or 2014, which will look nothing like human-inspired androids or robots. Maybe three years after his first phytomorphic machines, he envisions the debut of actual hybrids, half-plant, half-machine, giving mobility to the first and a form of intelligence to the second.
Bruno Giussani is the European Director of TED.
Plant’s Ability to Identify, Block Invading Bacteria Examined
This is a flower of the Arabidopsis thaliana plant. (Credit: (USDA-
Agriculture Research Service photo by Peggy Greb).)
ScienceDaily.com — Understanding how plants defend themselves from bacterial infections may help researchers understand how people and other animals could be better protected from such pathogens.
That’s the idea behind a study to observe a specific bacteria that infects tomatoes but normally does not bother the common laboratory plant arabidopsis. Researchers hoped to understand how infection is selective in various organisms, according to a Texas AgriLife Research scientist.
Dr. Hisashi Koiwa collaborated with colleagues in Germany and Switzerland to examine the immune capabilities of different mutations of the arabidopsis plant. Their findings appeared in the Journal of Biological Chemistry.
In this study, the team was trying to figure out how a plant defends itself rather than how it gets sick, said Koiwa, who provided about 10 different lines of mutant arabidopsis plants grown in his lab at Texas A&M University.
“By learning what is wrong with a sick plant,” he said, “we can study how a plant can defend itself, what mechanisms it uses for protection.”
The team had to examine the plants at the cellular level where molecules are busy performing different jobs.
To understand the process, one has to examine components such as “N-glycans, receptors and ligands,” Koiwa said.
The N-glycan is a polysaccharide that is critical in protein folding, a natural process which if it becomes unstable leads to various diseases, Koiwa explained. A receptor is a protein decorated with N-glycans which awaits signals from the ligands that bind and activate receptor molecules.
In viewing this mechanism across various arabidopsis plants that had been mutated to achieve different N-glycan structures, the researchers found one particular N-glycan that was critical in making sure that the receptor molecules can recognize the targeted bacteria molecule, he said.
If that polysaccharide can recognize a pathogen, it can prevent infection thus making the plant immune to that disease, the scientists noted.
“The question is fundamental. Why are we healthy in an environment of so many different bacteria?” Koiwa asked. “Why can one pathogen infect one kind of organism and not others? In this case, the same bacteria normally infects tomato plants but not arabidopsis.”
Koiwa said many researchers are studying the pathway, or molecular road, that a pathogen takes on its journey to infect another organism. They want to find what “gates” exist in an organism that prevent infection with the notion that the same blocks could be adapted in a susceptible organism to prevent disease.
He said eventually using this pathway to develop new plant varieties that do not allow pathogens inside the cells would be better than breeding lines that are merely “resistant” to diseases.
“In the case of resistance, a plant has to try to fend off an infection that has been let in,” Koiwa explained. “But a properly working immunity system does not let the pathogen in, so the plant does not get sick in the first place.”
The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Texas A&M AgriLife Communications.
Texas A&M AgriLife Communications (2010, March 21). Plant’s ability to identify, block invading bacteria examined.
- Southwestern North America and other subtropical regions are going to become increasingly arid as a consequence of rising greenhouse gases.
- The transition to a drier climate should already be underway and will become well established in the coming years to decades, akin to permanent drought conditions.
- This is a robust result in climate model projections that has its source in well represented changes in the atmospheric hydrological cycle related to both rising humidity in a warmer atmosphere and poleward shifts of atmospheric circulation features.
Lamont-Doherty Earth Observatory of Columbia University
Low water at Lake Powell (April 2003. Farley Canyon), photo by Eric Nyre, Canoe Colorado.
Projections of anthropogenic climate change conducted by nineteen different climate modeling groups around the world, using different climate models, show widespread agreement that Southwestern North America – and the subtropics in general – are on a trajectory to a climate even more arid than now. According to the models, human-induced aridification becomes marked early in the current century. In the Southwest the levels of aridity seen in the 1950s multiyear drought, or the 1930s Dust Bowl, become the new climatology by mid-century: a perpetual drought.
Mechanisms of Southwest and subtropical drying
Drying of the Southwest and the subtropics are caused by large scale changes in the atmospheric branch of the hydrological cycle. There are two aspects of this:
- The subtropics are already dry because the mean flow of the atmosphere moves moisture out of these regions whereas the deep tropics and the higher latitudes are wet because the atmosphere converges moisture into those regions. As air warms it can hold more moisture and this existing pattern of the divergence and convergence of water vapor by the atmospheric flow intensifies. This makes dry areas drier and wet areas wetter.
- As the planet warms, the Hadley Cell, which links together rising air near the Equator and descending air in the subtropics, expands poleward. Descending air suppresses precipitation by drying the lower atmosphere so this process expands the subtropical dry zones. At the same time, and related to this, the rain-bearing mid-latitude storm tracks also shift poleward. Both changes in atmospheric circulation, which are not fully understood, cause the poleward flanks of the subtropics to dry.
Besides Southwestern North America other land regions to be hit hard by subtropical drying include southern Europe, North Africa and the Middle East as well as parts of South America.
Future drying: historical droughts and Medieval megadroughts
The dynamical causes of imminent subtropical drying appear distinct from the causes of historical North American droughts such as occurred in the 1950s and during the 1930s Dust Bowl. Climate modeling has led to those being related to small, naturally occurring, changes in tropical Pacific (and, to a lesser extent, tropical Atlantic) sea surface temperature that also drive a change in atmospheric circulation that places anomalous descent over Southwestern North America..
The succession of ‘megadroughts’ – droughts like the Dust Bowl but which lasted for decades at a time – that occurred in the West in Medieval times have also been linked to equally persistent La Nina-like conditions in the tropical Pacific. However it is thought that the Sun was relatively strong at this time and volcanism weak which both would have resulted in positive radiative forcing of the climate system akin to rising greenhouse gases today. The differences and similarities of future drying with the Medieval megadroughts, and their global atmosphere-ocean contexts, needs to be determined.
In contrast to historical droughts, future drying is not linked to any particular pattern of change in sea surface temperature but seems to be the result of an overall surface warming driven by rising greenhouse gases. Evidence for this is that subtropical drying occurs in atmosphere models alone when they are subjected to uniform increases in surface temperature.
Will this really happen and what are the implications?
Imminent drying of the Southwest and subtropics in the models is such a robust result because it does not depend on poorly understood and highly parameterized parts of the model (such as cloud physics) but instead arises as a response of the large scale atmospheric dynamics – which we think is quite well represented in models – to a warming world. Similarly there is little reason to think that the models are wrong to have this response even if the dynamics involved need to be fully worked out.
Change in precipitation (P) minus surface evaporation (E) for the 2021-2040 period minus the average over 1950-2000. Results are averaged over simulations with 19 different climate models. P-E is the net flux of water at the surface that, over land, sustains soil moisture, groundwater and river runoff. Figure by N. Naik.
Drying of arid lands in the southwestern United States and northern Mexico will have important consequences for water resources, regional development and cross border relations and migration. According to the models the drying should already be underway and, over the length of time it takes to plan significant changes in water resource engineering and allocation (years to a few decades), will become well established.
The historical droughts were forced by natural variability of the tropical atmosphere-ocean system: persistent La Nina-like events in the tropical Pacific with a warm subtropical North Atlantic sometime playing a supporting role. Future drying is caused by overall warming. The aspect of the atmospheric circulation common to both is poleward shifted jet streams and mid-latitude storm tracks. But there are important differences that may allow identification of whether any drought that occurs is a naturally occurring one – and can be expected to end – or is anthropogenic – and can be expected to continue. For example droughts associated with persistent La Nina events involve increased heat uptake in the eastern and central equatorial Pacific Ocean and, hence, a cool tropical troposphere. The atmospheric dynamical response to this induces warming in the mid-latitudes. In contrast anthropogenic droughts will go along with warming almost everywhere and a maximum warming in the upper tropical troposphere. The tropical and subtropical zonal mean zonal winds are, necessarily, also distinct for natural and anthropogenic droughts. These differences may allow identification of onset of anthropogenic drying. Why La Nina events and global warming both induce subtropical drying is an active topic of research in atmospheric dynamics.
See also the GFDL Climate Modeling Research Highlight (volume 1, n5): Will the wet get wetter and the dry drier?
This work was performed as a collaboration of the scientists at Lamont-Doherty Earth Observatory (R. Seager, M.F. Ting, Y. Kushnir, H.-P. Huang, J. Velez, C. Li, N. Naik) NOAA Geophysical Fluid Dynamics Laboratory (I.M. Held, G. Vecchi, N.-C. Lau, A. Leetmaa) the National Center for Atmospheric Research (J. Lu) and Tel-Aviv University (N. Harnik).
Projected change in precipitation for the 2021-2040 period minus the average over 1950-2000 as a percent of the 1950-2000 precipitation. Results are averaged over simulations with 19 different climate models. Figure by G. Vecchi.