Plants Spring into Action 03/26/2011 March 26, 2011 — We shouldn’t take plants for granted. They seem so slow
and stationary, but actually they move and breath and carry on their lives in
truly amazing ways. Plants really show off their glory in the spring. But how
do they know, without eyes, what time it is? In “The science of spring,”
PhysOrg
explored how plants know when to spring into action when it’s time to come out
of their winter slowdown. Siburn Sung [U of Texas, Austin] found that an
interplay of genes responds to the temperature. In the lab plant
Arabidopsis, he found that a special molecule named COLDAIR is repressed
in winter, inhibiting the plant’s ability to produce flowers. After 20 days of
frigid temperatures, the molecule gets turned back on; but it takes another
10-20 days to prime itself for the warmth of spring. This begs the question,
though, of how genes respond to external factors, and how they measure the
days. “Well, we know that there are several things done by cold – but
how? That we don’t really know yet,” Sung remarked. Then he speculated
about the evolution of flowering plants. They evolved 150 million years ago, he
claimed, but had to learn how to deal with winter relatively recently.
Once it’s time to bloom, how do plants do it? Scientists from Harvard and
China, reporting in PNAS,1 tried to figure that
out. “Despite the common use of the blooming metaphor, its floral
inspiration remains poorly understood,” they began. They studied an Asiatic
lily and found that, contrary to earlier hypotheses about differential growth of
layers, “the edges of the petals wrinkle as the flower opens,
suggesting that differential growth drives the deployment of these
laminar shell-like structures.” This gave them some ideas: “This
functional morphology suggests new biomimetic designs for
deployable structures using boundary or edge actuation rather than
the usual bulk or surface actuation.” In Science this
week,2 Sarah Wyatt celebrated plant movement by
reviewing a new book called The Restless Plant by Dov Koller (Harvard,
2011). We need to unload our childhood impressions of plants as inanimate
objects, she said, and dance with the plants: “plants move. They just do so
on their own time scale and in their own way.” With the advent of
time-lapse photography, we can now appreciate their clever ways of getting
around.
The Restless Plant presents a “guided tour
of plant movements.” Koller starts with the classic, rapid leaf movements of the
sensitive plant and [Venus] flytrap but then provides a broader understanding of
plant movement that includes growth responses, expansion of plant
organs, and movements of individual cells and organelles. The world of
plants becomes a fascinating dance with many movements: contractile roots
pulling a bulb into the soil; the folding of leaves and flowers at
nightfall; leaves and flowers tracking the Sun; roots searching for
water and nutrients; the explosion of seeds into the world at large;
and growth responses to light, gravity, water, temperature, and touch.
Wyatt referenced Roger Hangarter’s Plants-in-Motion
web site that has time-lapse videos of plant movements (the one of morning
glory twining is pretty cool); the site actually includes an educational
green-screen tutorial on how students can actually dance with time-lapse videos
of plants in motion. Wyatt also referred to David Attenborough’s TV episode,
“The Private Life of Plants,” parts of which are viewable on YouTube.
Wyatt described plant movements as motorized to solve the physics
problems of mechanical motion:
“Motors” provide these movements, and,
although the use of the term for some of the responses is not without
controversy, the analogy is sound. For more rapid, reversible
movements, motors involve turgor-driven responses in specific
cells (pulvini) that are filled or drained of water as needed for movement. For
the slower growth movements, the tropisms, the motors are
growing cells within specific regions of the plant.
Some of the most basic things about plants remain
mysterious, she said; “the roots go down and the plant goes up and
nobody really knows how or why,” one botanist said. Wyatt was clearly
impressed with the “intricacies and beauty” of plant movements after
reading Koller’s book. “You will never look at plants the same way
again,” she said. If plants are so smart, maybe they like music,
too. The Royal Philharmonic Orchestra in London is trying to find out. PhysOrg
reported that “One of Britain’s most prestigious orchestras has performed to
a rather unusual audience – row upon row of plants, in an attempt to see
whether the music helps them grow.” The music, Mozart’s Eine Kleine
Nachtmusik and Symphony No. 40 is available for download on QVC
UK for gardeners who would like to continue the experiment. The site
includes a video clip of the orchestra playing the first movement of the 40th to
its leafy audience. Whether the plants responded is not yet known (they didn’t
applaud), but human viewers will get a kick out of the unusual experiment, and
will enjoy the timeless beauty of Mozart’s music while watching.
1. Liang and Mahadevan, “Growth, geometry, and mechanics of a
blooming lily,” Proceedings
of the National Academy of Sciences, published online before print March
21, 2011, doi: 10.1073/pnas.1007808108. 2. Sarah Wyatt, “Plant Science: A
Ballet of Plant Movement,” Science,
25 March 2011: Vol. 331 no. 6024 p. 1520, DOI: 10.1126/science.1203705.
Evolutionists are clueless about the evolution
of plants (12/30/2010, 09/22/2010, 07/03/2009), so run them out of symphony
hall so they won’t upset the daisies. Moody Institute of Science made one
of their most beautiful and intriguing films about plant movements back in the
1990s: Journey of Life (available from Christian
Book.com and Amazon). Parts of this were also incorporated in Wonders of
God’s Creation (see Moody
Publishers). Get these evergreen videos for your home library, and then get
into the garden or forest and look at your fellow travelers on God’s green Earth
with new appreciation.
[2011/03/26] Plants Spring into Action
