Can Plants Learn and Remember?

[Pythagorean]

Experience teaches plants to learn faster and forget slower in environments where it matters

Plants may lack brains and neural tissues but they do possess
a sophisticated Ca-signalling network in their cells
(Yang and Poovaiah 2003) similar to those underlying
memory processes in animals (Perisse et al. 2009). Specifically,
intracellular Ca ([Ca2+]i) signals are known to
regulate a large variety of functions in all biological organisms
(Berridge et al. 2000), including memory processing
and formation of memory imprints of past events ranging
from minutes to generations through gene expression (Perisse
et al. 2009; Gális et al. 2009). Interestingly in animals,
fluctuations in [Ca2+]i during learning seem to be essential
in priming the organism for the formation of long-term
memory, without affecting short-term memory (Perisse
et al. 2009; Bauer et al. 2002). In plants, this same [Ca2+]i
system is already known to contribute to the formation of
stress imprints (Conrath et al. 2001) and may be responsible
for the long-term memory we observed in Mimosa. As
a matter of fact, in both animals and plants, fluctuations in
[Ca2+]i levels are directly linked to stimulus–response coupling
through changes in the concentration of small molecules
and proteins, including calmodulin (CaM).

Gagliano, M, et al. (2013). Experience teaches plants to learn faster and forget slower in environments where it matters. Oecologia, Epub.

 

[jim mcnamara]

Another of Gagliano's papers. IMO, he is over-reaching for something the data may not support.

https://www.ncbi.nlm.nih.gov/pubmed/28382479 Plants find water using sound (?)

 

[Ygggdrasil]

Here's a provocative article from the New Yorker that addresses some research about whether plants exhibit behaviors like learning and memory. Here's an exerpt:

The quotation about self-censorship appeared in a controversial 2006 article in Trends in Plant Science proposing a new field of inquiry that the authors, perhaps somewhat recklessly, elected to call “plant neurobiology.” The six authors—among them Eric D. Brenner, an American plant molecular biologist; Stefano Mancuso, an Italian plant physiologist; František Baluška, a Slovak cell biologist; and Elizabeth Van Volkenburgh, an American plant biologist—argued that the sophisticated behaviors observed in plants cannot at present be completely explained by familiar genetic and biochemical mechanisms. Plants are able to sense and optimally respond to so many environmental variables—light, water, gravity, temperature, soil structure, nutrients, toxins, microbes, herbivores, chemical signals from other plants—that there may exist some brainlike information-processing system to integrate the data and coordinate a plant’s behavioral response. The authors pointed out that electrical and chemical signalling systems have been identified in plants which are homologous to those found in the nervous systems of animals. They also noted that neurotransmitters such as serotonin, dopamine, and glutamate have been found in plants, though their role remains unclear.

Hence the need for plant neurobiology, a new field “aimed at understanding how plants perceive their circumstances and respond to environmental input in an integrated fashion.” The article argued that plants exhibit intelligence, defined by the authors as “an intrinsic ability to process information from both abiotic and biotic stimuli that allows optimal decisions about future activities in a given environment.” Shortly before the article’s publication, the Society for Plant Neurobiology held its first meeting, in Florence, in 2005. A new scientific journal, with the less tendentious title Plant Signaling & Behavior, appeared the following year.

The full article is definitely worth a read: http://www.newyorker.com/magazine/2013/12/23/the-intelligent-plant

Of course, there is definitely a lot of pseudoscience and crackpottery in this area, but also a lot of legitimate research.

 

[Pythagorean]

Hello 2014!

I think one thing that probably gets easily equivocated is concepts like "learning" and "memory". Not to each other, each concept get equivocated with their own analogues. Memory has a pretty broad range of definitions, including computing and materials science. It's a ubiquitous concept. Even in a single organism, there's many kinds of memory, some of which may overlap with plants. Learning is similar, but a bit more nuanced; we do now speak of machines learning. As top level concepts, neither of these, as they may exist in plants, are necessarily the same as human learning and memory. There's no evidence there's an experience involved for the plants, for example, but humans tend to think of learning and memories as experiences and that will always be a tempting leap. Journalists (and some researchers, whether implicitly in scope or explicitly in the discussion section) and the public will inevitably anthropomorphize it, anyway.